Nuclear Strategy Archives - Texas National Security Review

A Primer on Analyzing Nuclear Competitions

Nuclear Strategy July 2019

Bruce Sugden offers a nuclear primer for analysts studying nuclear competition, urging them to broaden the range of plausible “what if” questions around which their studies are structured.

How to Think About Nuclear Crises

Nuclear Strategy February 2019

Mark S. Bell, Julia Macdonald

How dangerous are nuclear crises? What dynamics underpin how they unfold? Recent tensions between North Korea and the United States have exposed disagreement among scholars and analysts regarding these questions. We reconcile these apparently contradictory…

Rethinking the Bomb: Nuclear Weapons and American Grand Strategy

Nuclear Strategy January 2019

Francis J. Gavin

Nuclear weapons have long played a central but often unappreciated role in American grand strategy. In spite of the unimaginable consequences of their use in war, we know far less about how the bomb shapes U.S. national security and world politics than we…

Marching Toward a U.S.-North Korea Summit: The Historical Case for Optimism, Pessimism, and Caution

Nuclear Strategy May 2018

Patrick McEachern

The history of denuclearization efforts on the Korean peninsula gives reason for pessimism, caution, and optimism. Attempting to critically engage that history can help the United States narrow uncertainty, prepare for a long diplomatic process should one…

North Korea Defied the Theoretical Odds: What Can We Learn from its Successful Nuclearization?

Nuclear Strategy February 2018

Nicholas L. Miller, Vipin Narang

How well do the existing theories about nuclear proliferation predict North Korea's successful nuclearization?

Just because nuclear war is undesirable and the probabilities of it occurring are very low is no reason not to think about it.[1]

—Secretary of Defense James Schlesinger (1974)

The U.S. government has recognized that great power competition is the principal feature of the international security environment that puts U.S. national interests at risk. Every public strategy document released in the last two years, including the 2017 National Security Strategy, the 2018 National Defense Strategy, and the 2019 Missile Defense Review, has highlighted the centrality of great power competition.[2] The 2018 Nuclear Posture Review clearly extends the centrality of that competition to the realm of nuclear forces.[3] However, while identifying the challenges of nuclear competition — between the United States and Russia on the one hand, and the United States and China on the other — is a crucial first step for making strategic assessments, these strategy documents provide little in the way of guidance for analyzing nuclear competition. This article aims to fill that gap by discussing a strategic-analytic framework for generating useful research on the U.S. competitive position relative to its potential nuclear adversaries.[4] Several elements of the framework are discussed within the context of exploring the approaches to analyzing military competitions and, in particular, identifying the key features of a nuclear competition. The final section provides the reader with several cautionary notes for how to avoid analytic traps in designing a strategic assessment of a nuclear competition.

The Role of Nuclear Competitions Between Great Powers

Perhaps beginning with President Barack Obama’s foreign policy initiative to “rebalance to Asia and the Pacific,” the United States government has been recovering from its post-Cold War holiday. This was a time in which a large proportion of U.S. national security departments and agencies abstained from analyzing and preparing for the potential strategic implications of the growth of the Chinese economy and military, the stabilization of the Russian political economy and the ascendance of the regime of Vladimir Putin, and the decline of the U.S. nuclear weapons enterprise for America’s standing in the international security environment and its national security interests.[5] A key step in that recovery has been acknowledging, as formalized in the 2017 National Security Strategy, that the United States must be an active great power competitor if it wants to safeguard its worldwide strategic interests and maintain the credibility of its defense commitments to allies in Europe and in East Asia in the face of challenges from Russia and China. Since their advent in 1945, nuclear weapons have been part and parcel of great power competition, though as the United Kingdom, France, India, Pakistan, and North Korea demonstrate, nuclear weapons are not the exclusive province of great powers. Like military forces in general, nuclear weapons are tools of statecraft, and, since 1945, great powers have wielded them for a variety of purposes:[6] to deter nuclear and non-nuclear attacks against a great power’s homeland and that of its allies, to conduct military missions and achieve wartime objectives if deterrence fails, to act as a visible sign of assurance to weaker allies of the security patron’s commitment to their defense, to coerce other states, and to hedge against geopolitical and technological surprises.[7] Relatedly, great powers have used their nuclear forces to compensate for what they have perceived as the relative military inferiority of their conventional forces. Take, for example, the U.S. military posture and force planning of the 1950s and 1960s, or Russia’s post-Soviet-era reliance on nuclear weapons in its force structure.[8] Nuclear competitions involving the United States have been a feature of the international security environment for decades.[9] Russia has remained an active nuclear competitor since the end of the Cold War — it has sustained and modernized a robust nuclear arsenal along with the applicable military doctrine, training, and exercises.[10] China’s rise as a major regional power — including its deployment of a diverse array of military forces to deny U.S. forces access to the waters and airspace between its coastline and the Second Island Chain (stretching roughly from the Japanese island of Honshu, through Guam and on to Indonesia) and its military encroachments on disputed territories within the South China Sea — has corresponded with significant qualitative improvements to its nuclear forces.[11] One notable improvement has been the deployment of road-mobile launchers for intercontinental ballistic missiles (ICBMs) and associated hardened underground facilities to enhance their survivability against attack. This development could diminish the effectiveness of a U.S. counterforce attack against Chinese nuclear forces and affect U.S. planning for the defense of regional allies and the U.S. homeland. In sum, nuclear weapons have gone hand-in-hand with great power competitions since the end of World War II. Because the great powers have continued to strengthen their nuclear forces and use them as tools of statecraft in various ways since the end of the Cold War, nuclear competitions continue to be salient in great power military competitions. With several public U.S. strategy documents pointing to a reinvigorated great power competition, the next section addresses the nature of great power military competitions.

What Are Great Power Military Competitions?

In the nuclear era, a great power can be defined as either the leading state in terms of relative military power, or a state that has sufficient relative military power that it could fight the leading state to the degree that a war of attrition could result. A great power must also maintain a secure nuclear second-strike capability,[12] without which the leading state could effectively disarm it. The literature on great power competition and rivalry makes clear that such a competition is a “political-military-economic competition between two states. This competition extends over many decades, even prospectively a century or more.”[13] Great power competition, however, does not necessarily imply conflict. It lies on a spectrum whose extremes are marked by both conflict and cooperation.[14] In some areas of international politics, two great powers can have a convergence of interests that enables cooperation, such as in nonproliferation of nuclear weapons or in counter-terrorism efforts, while in other areas they can have a conflict of interests, such as in territorial disputes between themselves or between their client states. As the U.S.-China competition demonstrates, competitors can trade goods while also equipping themselves for war with one another. The underlying source of tension remains fear and mistrust between two great powers that cannot be easily subdued with military force and whose intentions cannot be discerned with high confidence.[15] [quote id="1"] The literature points to a multitude of reasons why great powers compete with one another. Paul Kennedy, for example, finds that the sources of the competition between Britain and Germany in the late 19th century were economic, geographic, and ideological. As he puts it,

[T]he Anglo-German antagonism basically arose from the fact that in the half-century under scrutiny Germany grew out of its position as ‘a cluster of insignificant States under insignificant princelings’; and from the further facts that this growth gradually threatened to infringe perceived ‘British interests’, that these economic shifts increased the nervousness of British decision-makers already concerned about ‘saving the Empire’, and that they were accompanied by ideas about a German mission which could be adopted by political forces grappling with severe domestic problems.[16]

Aaron Friedberg echoes Kennedy in describing the causes of the U.S.-China competition.[17] Friedberg argues that, notwithstanding the zero-sum nature of the economic and military aspects of the competition, a central element is that the United States and China maintain a different set of core political beliefs and ideologies. America’s post-Cold War policy for dealing with China has been tied to liberal ideas about the interconnectedness of trade, economic growth, democracy, and the protection of human rights, while China — a single-party state led by the Chinese Communist Party, which is fixated on maintaining its hold on power — has pursued policies that reflect the ruling regime’s authoritarian and illiberal character.[18] In order to understand what a military competition is, analysts can turn to the writings of Andrew Marshall, who was a member of the first generation of analysts seeking to understand the nature of the U.S.-Soviet military competition and, most important, how to assess the relative standings of the competitors over time.[19] In his 1966 study, Marshall describes military competition as two countries, or groups of countries, organizing, training, and equipping their military forces to deal effectively with the military forces of the other in one or more potential contingencies.[20] This definition encompasses not only weapons systems, but also doctrine, military education and training, command and control, logistics, and military exercises. Moreover, by using the term “military competition,” Marshall makes clear that his focus is on the military sector of the larger strategic competition. The focus on the military aspects of the strategic competition is especially important, as Marshall and James Roche argued in 1976, if the analytic objective is to understand and improve how the Defense Department might better position its investments portfolio for the strategic competition (the Defense Department, after all, is responsible to the president for the military arm of national power).[21] Analyzing Military Competitions How, then, should one analyze military competitions and estimate a competitor’s relative military power? There are three analytic approaches to this question, which aim to either forecast a competitor’s future military posture and capabilities or understand the potential outcome of a combat interaction between the competitors’ military forces in a specific military contingency or group of contingencies. For a comprehensive understanding of military competition, it is necessary to incorporate all three approaches. First, in exploring and characterizing military competitions to forecast a competitor’s future military capabilities and posture, Marshall found that a promising approach is to start with a detailed historical analysis of the evolution of the competitors’ military forces. This analysis ought to, in turn, highlight whatever is known about asymmetries between competitors’ military thinking, in tactical doctrine, in organizational practices and styles of command and control, as well as the historical preferences of the relevant organizations that provide input or make decisions about military capabilities and posture.[22] Such an in-depth and lengthy study, Marshall believed, was needed to understand the long-term decision-making behavior of military organizations and other organizations relevant to shaping a state’s military forces and posture, in order to forecast a competitor’s military power beyond five years. A second approach is to study the interaction of military forces in a particular military contingency (e.g., the interaction of U.S. and Chinese nuclear forces in a conflict over Taiwan that begins with conventional combat). When Marshall offered a framework of what such an assessment might look like in 1983, he used the military balance in Europe between the North Atlantic Treaty Organization (NATO) and the Warsaw Pact as an example.[23] To conduct such a study, an analyst would begin by selecting a geographic area that can be distinguished from others by the nature of its military problem and then determine and compare what objectives the opposing forces would try to achieve and with what ways and means. If, in such a comparison, the U.S. objective is to deter a military attack, then the analysis would initially emphasize the competitor’s assessment of the military balance. The competitor’s assessment should be that the balance favors the United States — that is, the competitor cannot achieve its objectives through military operations. In analyzing the balance of military forces, the analyst should select a military contingency that covers a range of plausible situations that will test the capabilities of the forces: for example, U.S. power projection to a region not normally considered a likely combat zone, or the competitor’s military deception operations.[24] Interestingly, some analysts make the mistake of characterizing conventional balances as being set in stone and unable to evolve.[25] To these analysts, the United States has enjoyed such significant and enduring conventional advantages over potential nuclear adversaries since the early 1990s that it may safely dismantle its nuclear capabilities or force-employment capacities, or impose upon itself doctrinal restraints with minimal or no consideration for how long it might take to reconstitute these capabilities or capacity levels. Yet, in the span of less than 10 years, amid signs that the U.S. competitive position in the military balances in Europe and East Asia has declined, it appears that those analysts’ earlier assessments of the conventional balances have not withstood the test of time. It is important to recognize that military balances — whether conventional or nuclear — between the United States and its military competitors change in reaction to various actions taken by competitors, including procurement of different types of weapon systems, training military forces for particular missions, and developing and exploiting technological breakthroughs.[26] The evidence since 1995, for example, suggests that China’s investment in conventional precision-strike capabilities has eroded U.S. military advantages in plausible Western Pacific conflict scenarios.[27] The Chinese military is better equipped in 2019 than it was in 1995 to at least delay the sustained intervention of U.S. air and naval surface forces in a China-Taiwan theater of operations — if not completely deny them access.[28] In addition, China’s deployment of mobile ICBM launchers, which increases the survivability of its nuclear forces, suggests the nuclear balance between China and the United States might be less favorable to the latter than it was 20 years ago. [quote id="2"] Likewise, the conventional military balance in Europe between the United States and Russia does not favor U.S. forces in 2019 to the same degree that it did two decades ago.[29] Gen. Philip Breedlove, former commander of U.S. European Command, stated in 2015 that U.S. European Command was seeing growing Russian capabilities and significant military modernization. As a result of those developments, Breedlove characterized U.S. European Command as assuming “significantly greater risk. Our timelines are longer, our preparations are less robust, and our fundamental ability to deter and defeat in a timely and effective manner is less sure than it could be.”[30] In 2018, Gen. Curtis Scaparrotti, Breedlove’s successor at U.S. European Command, clarified that understatement in testimony before the U.S. Congress: “I don't have all the forces I need in Europe today, and we have got to continue to invest and establish the posture that is required.”[31] Military balances in general are not based solely on the number of units or weapon systems each competitor has deployed in likely theaters of operations. To be comprehensive, any analysis of a military balance should incorporate the competitors’ concepts of operations and how they practice warfare.[32] Other useful elements to consider might include, but are not limited to, the readiness levels of theater-based forces, the rates at which the competitors could reinforce those forces, the security of their lines of communications, abilities to sustain effective combat units, and command-and-control capabilities. For protracted war scenarios that could include the intermittent use of nuclear weapons, understanding the abilities of competitors’ conventional forces to fight amidst the after-effects of a nuclear weapon strike (i.e., blast, thermal radiation, prompt and residual radiation, and electromagnetic pulse) could be critical to developing an accurate assessment of the military balance. Interestingly, Richard Betts’ 1980s argument remains relevant to thinking about contemporary and emerging conventional military balances: History demonstrates that the initial phase of war might be as bad for the defender — even one that enjoys a numerical advantage — as worst-case estimates would suggest for two reasons. First, a defense posture and plan cannot account for all plausible regional military contingencies with a given competitor. Rather, strategists and planners will whittle down plausible contingencies to those most likely to occur. Second, attackers have time to assess the defense and develop offensive operations that will exploit observable weaknesses.[33] In the end, it pays to take a long view of the balance of military forces between the United States and its competitors, rather than painting a static picture. A 2016 Institute for Defense Analyses report showed that, since the late 1980s, the median time required for major defense acquisition programs (including initial development) to reach initial operational capability was approximately eight years. This included aircraft, ground systems, space systems, and ships.[34] Therefore, analysts should look at key trends that will shape particular military balances over a minimum of 10 years to give Defense Department senior managers sufficient time to direct changes in investment portfolios to sustain U.S. advantages or to develop new ones. The third analytic approach to understanding military competition is to describe and assess the implications of the military investment balance.[35] Undertaking such an assessment will require looking at the allocation of national resources to research and development efforts in technological areas that might serve as latent military power (i.e., designed but unproduced military capabilities) that a competitor could exploit in the future, perhaps during a protracted conflict. An assessment of the military investment balance can shed light on how seemingly nonmilitary investments, such as those from a nondefense organization, might have utility in a military balance or its evolution. It would also better capture a competitor’s defense-related investments and how that competitor might seek to sustain or gain advantages in particular areas of a military competition. For example, a country’s deep underground facilities are also a means to defend senior leaders or other critical personnel against conventional and nuclear attack. Or consider this: During the Cold War, the U.S. nuclear weapons complex — a Department of Energy responsibility — exercised all phases of its nuclear weapons life-cycle process, from the research phase, all the way through production, and eventually, retirement and dismantlement. However, according to the Defense Department, “U.S. nuclear weapons have not undergone the full life-cycle phase process since the completion of the W88 [warhead] Phase 5 in 1991.”[36] What if U.S. competitors have been exercising all, or most, of the life-cycle phases for their nuclear weapons, particularly research and development of different weapon designs and effects, something that the United States has abstained from for nearly thirty years? What might be the implications for how nuclear competitions will evolve? Moreover, what might disparities in dormant weapons-production capacity mean for a nuclear competition if one competitor mobilizes that capacity during a crisis or conflict?[37] Prior to discussing the remaining elements of a framework for analyzing nuclear competitions, it is important to keep in mind that military competition occurs within a broader strategic competition wherein the economic resources of the competitors need to be addressed. A comparative economic analysis should shed light on how efficient and effective competitors are relative to one another in allocating a proportion of their economic resources for a long-term military competition.[38] Marshall suggested that there are several components to being an effective and efficient competitor: being a low-cost producer of effective military forces while bringing about higher costs for the competitor; maintaining the health of key areas of the defense-industrial base; steering the competition into areas where one has advantages and enjoys enduring technological leadership; and choosing to trail in areas of military competition where one might be much less effective and efficient in sustaining a military advantage.[39] Relatedly, at a broader level, analyzing the political economy of a competitor can serve as a backdrop to understanding its “fitness” for long-term military competition. David D’Lugo and Ronald Rogowski’s analysis of the Anglo-German naval race offers insights into thinking about the extent to which a competitor’s political institutions and social actors (e.g., labor unions or industrial blocs) support resource extraction from the economy to generate military power.[40] In another case, there is evidence suggesting that the U.S. nuclear force structure and posture during the Cold War were principally driven by the political economy of U.S. military commitments to Europe.[41]

Key Features of Nuclear Competitions

What is special about nuclear competitions? First, nuclear weapons possess enormous destructive power and, when mated to high-speed missiles, can be quickly delivered to targets over long distances. The speed of delivery makes a nuclear strike extremely difficult to defend against. Second, nuclear weapons, unlike conventional weapons, have the potential to produce long-term, wide-area effects due to radioactive fallout. Finally, in most, if not all, nuclear states, the policy for using nuclear weapons is determined to a great extent at the most senior level of leadership.[42] Lower-level officials, planners, and analysts in military organizations — and some in nonmilitary organizations — however, are the ones generating the options that are ultimately presented to senior leaders in order to make these policy decisions. The next three features to be discussed are applicable to all military competitions, not just to nuclear ones. Nevertheless, some arguments and debates about U.S. nuclear policy and strategy and the state of nuclear competitions have obscured or ignored these features. Therefore, they will be described and analyzed in terms of how they relate to understanding a nuclear competition. The Importance of the Competitive Context When Considering Nuclear Strategy A key feature of nuclear competition — oftentimes obscured by histrionics in debates about nuclear policy, strategy, and forces — is that competitive interaction is the foundation for thinking through the issues surrounding nuclear forces and doctrine. U.S. nuclear forces and nuclear doctrine are not designed in a vacuum. And yet, some analysts have given short shrift to the competitive political and military setting in which nuclear operations would take place.[43] This oversight often leads to two analytic weaknesses. First, downplaying the competitive context results in the failure to account for how changes in a competition might render particular U.S. forces and doctrine ill-suited to achieving U.S. policy objectives. Furthermore, U.S. forces may be less effective against an emerging competitor if they have been designed and postured with another competitor predominantly in mind. Second, it also leads to an underappreciation of the uncertainty about how U.S. leaders might react to a variety of political and military conditions surrounding a future conflict, as well as the uncertainty about how U.S. competitors might view America’s willingness and ability to effectively use military forces against their own forces to achieve wartime objectives. With the competitive context in mind, analysts are better positioned to understand how a nuclear competition is evolving and to construct the bridge between U.S. policy objectives (including potential war aims) and the ways in which available military instruments may be used against a dynamic opponent in today’s — and tomorrow’s — strategic setting.[44] Investigating the strategic and operational adequacy of U.S. nuclear forces within the competitive context will help analysts explicitly incorporate into their research designs a number of questions: How effective might America’s military forces and those of its competitor be in particular conflict scenarios (e.g., comparing training and readiness, tactics and operational concepts, and how well those tactics and operational concepts exploit existing technologies in the operational environment)? How might forces be employed in pursuit of different national objectives, and what types of force employment concepts might constitute escalation and warrant a nuclear response?[45] With the competitive framework anchoring the analysis, the issue of how potential nuclear adversaries might defend their ability to wage military campaigns against U.S. attempts to halt them ought to garner more of the analyst’s attention. To wit, what ought to be debated is not whether the United States should deploy new types of low-yield weapons, but whether current low-yield weapons are allocated to the most capable delivery systems or platforms in light of likely operational environments.[46] [quote id="3"] Failing to account for the competitive context, moreover, could lead some analysts to inaccurately identify the possible decisions that U.S. and adversary leaders would make in potential conflict scenarios as well as the plausible range of combat outcomes between opposing forces.[47] To be clear, such analyses do not reveal careful consideration of the range of variables that might shape combat outcomes, operational planning, and strategic decision-making.[48] Further muddying the task of identifying the plausible range of conflict conditions and combat outcomes between opposing forces, it is axiomatic that in any military competition, competitors seek to complicate one another’s planning to gain advantages in future conflicts.[49] Their tools for doing so include information denial, deception, ambiguous declaratory policies, and forces capable of performing multiple military missions.[50] In a crisis and wartime scenario, competitors might try to conceal their true political and military objectives to throw off the other’s efforts to gain advantages.[51] Times of crisis and war will create unforeseen pressures and dynamics that will influence decision-makers. They can predict neither the full scope of options that will be available to a competitor nor the options that will be available to themselves. Analysts should acknowledge that they are constrained in the same way.[52] In a hypothetical conflict in the Baltic states, for example, Russia’s deployment of nonstrategic nuclear weapons and dual-capable delivery systems raises the possibility that the first use of a nuclear weapon could be at sea involving a Russian anti-ship strike against a U.S. surface combatant, perhaps an aircraft carrier, or it could be against U.S. aircraft approaching Russian airspace.[53] At the same time, Russia could use other levers to generate political fissures within NATO — between Western Europe and the Baltic states, between Europe and the United States, and between the citizens of European states and their governments. Perhaps Russian leaders calculated that nuclear use at sea or in the air would not elicit a larger U.S. nuclear response, or that an equivalent U.S. response would come at the cost of deeply fracturing NATO (something Russian leaders would be delighted to see). Or perhaps the Russians miscalculated. The Role of Non-Nuclear Technologies in Shaping Nuclear Competition A second key feature of nuclear competitions is that, due to current and anticipated technical advances in a wide range of military capabilities, the proliferation of non-nuclear systems will shape nuclear competition to a greater degree in the future than it did before 1991. Critics of U.S. nuclear policy sometimes emphasize the ability of U.S. military forces to carry out cross-domain deterrence: for example, threatening to carry out a non-nuclear attack to deter a nuclear one.[54] Yet, cross-domain deterrence does not necessarily mean relying solely on one or two favored types of weapons or domains of military operations (i.e., air, sea, ground, or cyber) to deter threats. It is really about coordinating and synchronizing forces and different types of weapons to generate credible threats in the eyes of adversaries. Some of those responses could utilize a combination of arms and a cross-domain approach to enhance their effectiveness. Thus, figuring out how a competitor might deploy and employ nuclear forces during the next 20 to 30 years requires accounting in some useful way for the non-nuclear forces that will be available for use alongside them. A competitor’s non-nuclear forces may affect how it uses nuclear weapons in a crisis or conflict to achieve a particular objective, and that use might, in turn, shape competitors’ deployment of non-nuclear and nuclear forces or their decision to employ nuclear weapons to achieve their objectives. As critics of new low-yield nuclear weapons point out, conventional precision-strike systems are capable of conducting effective strikes against some types of targets that were once only assigned to nuclear weapons systems.[55] This does not mean, however, that conventional capabilities will completely crowd out nuclear weapons in countries’ operational plans. Tailored nuclear weapons, for example, might be the most effective for destroying particular hardened targets when non-nuclear means cannot be relied on to do the same or to degrade the target’s military effectiveness.[56] When used in the role of missile defense, the radiation output of a nuclear weapon is likely to produce a lethal radius exceeding that of conventional weapons, thereby increasing the chance of disabling an incoming delivery vehicle that is inadequately hardened against radiation effects.[57] Many nuclear competitors seem to believe that non-nuclear active missile defenses hold the prospect of being more effective today than when first deployed decades ago; however, in some cases, the size of a missile raid and the use of counter-measures could reduce their effectiveness.[58] Thus, the possibility of intercepting inbound nuclear-armed delivery vehicles has implications for nuclear escalation.[59] In addition, computer network attack and defense could affect nuclear command, control, and communications in a crisis or conflict, while a competitor’s views of the wartime survivability and effectiveness of its own space-based capabilities — intelligence, surveillance, and reconnaissance; communications; and missile early warning systems — might affect how it sees its chances in a nuclear conflict.[60] For example, the loss of space-based platforms with multiple-mission payloads in an ongoing non-nuclear conflict might lead to a nuclear response. Conventional and Nuclear Operations Are Interdependent The third key feature of a nuclear competition, somewhat related to the role of non-nuclear technologies, is that assessing how the character of the nuclear competition under peacetime conditions might look different under wartime conditions cannot be completely divorced from other areas of the military competition. Thus, policy and strategy debates would benefit from examining the plausible multidomain dynamics and complexities of potential conflicts, including nuclear-use scenarios, through an operational lens to better understand the relative strengths and weaknesses of U.S. warfighting capabilities.[61] Analysis of and planning for integrated conventional and nuclear operations is important for at least two reasons. First, how nuclear operations evolve during a conflict will, to some extent, depend on how conventional operations play out, and vice versa. For example, if U.S. forces were to conduct conventional suppression of enemy air defense operations against Russia’s integrated air defense system within its Western Military District, Russian leaders could perceive the effort as threatening the security of the state, thereby provoking the use of nuclear weapons to compel U.S. de-escalation. Similarly, Chinese leaders might interpret U.S. conventional strike operations against the People’s Liberation Army Rocket Force units and command-and-control infrastructure as a way to degrade China’s nuclear deterrent.[62] Such an interpretation could result in Chinese nuclear strikes against U.S. military targets in the Pacific region. Second, nuclear strikes can be used in tandem with conventional precision-strike systems to make offensive operations more effective.[63] For example, if a competitor fears the effectiveness of an opponent’s terminal-phase missile defense system — the last opportunity to intercept a missile before it hits its target — it might initiate a broad conventional-strike campaign by first detonating a nuclear weapon at high altitude to disrupt the transmission of radar waves with the intent of degrading the opponent’s missile defenses.[64] Perhaps, just as during the Cold War phase of the U.S.-Russia nuclear competition, U.S. conventional forces must be organized, trained, and equipped to survive and remain effective in a battlefield that sees the use of nuclear weapons to have any chance of providing decision-makers with non-nuclear options for warfighting and deterrence. Although the Russian government would prefer to conduct military operations under the threat of nuclear weapons use rather than their actual use, the combination of Russia’s limited conventional-strike force structure, likely regional adversaries, and potential war aims translates into the Russian military planning and practicing for a nuclear battlefield.[65] In Russian exercises and war games, the use of nuclear weapons in battlefield-support missions can mark the early and middle phases of conflicts — and the Russian military is trained and equipped accordingly.[66] [quote id="4"] One key difference between the Russian and the Chinese militaries is that the former is better equipped for integrated conventional-nuclear operations. For many political reasons, both international and domestic, the Chinese military might improve its position in this area of the U.S.-China competition in the near future. With advances in Chinese long-range conventional precision-strike technologies, for example, the rocket force could transfer those technologies to its nuclear forces and broaden the range of operational concepts available to Chinese war planners.[67] Meanwhile, there is no open-source evidence to suggest that U.S. conventional forces are better off than they were in 2011 when the Department of Defense’s Defense Science Board concluded that “the survivability, effectiveness, and adaptation of [conventional forces] to [a battlefield in which nuclear weapons have been used] is at best unknown.”[68] No wonder that the 2018 Nuclear Posture Review stated that combatant commands and service components will plan, train, and exercise to integrate nuclear and non-nuclear forces and to operate in a nuclear battlefield.[69] The Defense Department will need to invest in increasing the ability of U.S. conventional forces to operate in a nuclear battlefield, especially if the United States wants the option of refraining from an in-kind nuclear response to a hypothetical Russian nuclear strike against NATO forces, as some analysts have recommended.[70] These recommendations raise the question of how to configure U.S. conventional forces for a possible protracted conflict in which only one side is utilizing nuclear weapons. U.S. nuclear restraint in this scenario might invite Russia to continue to use nuclear weapons and lead to the rapid degradation of U.S. and allied conventional forces (in addition to undermining U.S. extended deterrence commitments and nuclear nonproliferation efforts). Nuclear self-restraint and reliance on conventional operations after a competitor has used nuclear weapons raise a number of challenges for the U.S. military’s current and planned force structure and posture, especially regarding a possible conflict in Europe. For example, in light of the 2011 Defense Science Board report and U.S. European Command’s post-2001 emphasis on operations outside of NATO members’ borders, U.S. airbases overseas are less capable of supporting flight operations for extended periods of time due to a lack of training and equipment geared toward reconstituting the bases’ capabilities following a nuclear strike.[71] In addition, while the U.S. Army should be re-assessing its tactics for resolving the dilemma between how its ground forces mass for effective attack versus how they space out units to avoid presenting themselves to enemy forces as inviting targets as Russia continues to improve its ability to conduct conventional precision strikes, it should also be taking steps to ensure it can conduct effective operations on a nuclear battlefield. Such steps may include hardening its equipment against the effects of a nuclear strike, reviewing its decontamination procedures and possibly enhancing its decontamination equipment, and planning how to regain the battlefield initiative and its control of the tempo of operations following a nuclear strike.[72] The challenges of ensuring survivable conventional forces in a potential European nuclear battlefield suggest that it will not be easy to terminate a conflict on favorable terms against an adversary using nuclear weapons while U.S. forces use only conventional operations and other non-nuclear tools. They also indicate that both conventional and nuclear forces constitute the anti-access and area denial problem that the U.S. military has been fixated on for years (an adversary’s anti-access and area denial systems increase the distance between its assets and areas from which the United States can operate its military forces with impunity).[73] Analysts should consider this area fertile ground for more comprehensive examination.

Avoiding Pitfalls in Analyzing Nuclear Competitions

There are five additional considerations, or guidelines, to keep in mind while analyzing a nuclear competition or structuring an assessment of a given nuclear balance involving the United States that will help to avoid analytic weaknesses that will derail the integrity of the findings or of the diagnosis. First, U.S. extended deterrence commitments and alliance politics complicate U.S. nuclear policy and strategy and force structure decisions, as well as combined allied military planning. If the aim of analysis is to ensure the adequacy of U.S. military capabilities, then the potential for additional and novel problems to surface for Defense Department planners and U.S. decision-makers during a crisis or war should not be excluded from the analysis or substituted with rosy assumptions. Second, because analysts are limited in their ability to foresee all of the critical circumstances of a future battle space and to discern an adversary’s future intentions, they should not discount the possibility of the limited use of nuclear weapons. Third, strategic analysts should be skeptical about the utility of social scientific theories and models of complex human interactions under the nuclear shadow, unless those theories and models account for how key features of a nuclear competition, based on empirical evidence, will influence its peacetime evolution and how those features might shape military operations. Fourth, competitors’ peacetime nuclear declaratory policies are inadequate guidelines for bounding the scope of an analysis of a nuclear competition. These policies could change quickly once the leadership confronts the reality of a crisis or war. Fifth, the nature of a nuclear war will ultimately be defined by politics. The possibility of one or more belligerents making concessions to bring the war to a close means that nuclear annihilation is not the only possible outcome after the initial use of nuclear weapons. No A Priori Resolution of U.S. Extended Deterrence Problems Some critics of enhanced U.S. nuclear weapon capabilities or posture are dismissive of the military and political challenges that U.S. extended deterrence commitments might pose for U.S. decision-makers over the next 20 to 30 years.[74] These critics are convinced that, in the eyes of potential adversaries, the United States and its allies have a credible deterrent. But they are unclear about what specific actions can be deterred and under what particular conditions, what factors make the deterrent credible to adversaries, and for how long adversaries may believe the U.S. deterrent threats to be credible.[75] Sometimes, these critics seem to suggest that potential adversaries perceive robust coupling between the U.S.-based nuclear arsenal and the local defense of U.S. allies; however, adversaries’ perceptions and how they might change over time are usually opaque or indeterminate to external observers.[76] Because of this significant uncertainty, a key element of U.S. defense planning has been to deploy and posture forces to minimize the ability of and the incentives for potential adversaries to devise and implement operational plans for achieving their war aims. U.S. leaders have also tried to assure a disparate set of allies of the U.S. commitment to their defense and keep them aligned on policy and strategy.[77] U.S. leaders from both major political parties have long wanted a robust set of military options for dealing with a nuclear competitor’s potential challenges to U.S. extended deterrence commitments. The takeaway, though, is not that the United States should simply develop and deploy all possible types of nuclear options so that it can have in-kind responses ready for the many ways competitors might use nuclear weapons. Rather, it is that it is reasonable to expect that future U.S. decision-makers will not want the United States to accept being a strategic hostage to an adversary’s ability to launch a nuclear strike at the U.S. homeland. Nor will decision-makers want to cede the initiative to an adversary in regional conflicts that threaten U.S. overseas interests. History suggests that decision-makers will want a toolkit equipped with multiple nuclear and non-nuclear capabilities to manage alliance politics, deter different forms of aggression, and mitigate operational challenges. The act of deterring a particular adversary action is essentially to sustain a threat to impose costs on the adversary or deny it a benefit, if it commits that action.[78] The effectiveness of the threat, moreover, is inextricably connected to whether the adversary believes that the defender is willing to absorb the costs that may come with fulfilling that threat. The higher the costs that are thought to be associated with fulfilling the deterrent threat, the less credible the deterrent threat is likely to be in the mind of the adversary. In concrete terms, nothing is more important to a nuclear competitor than the security of its homeland. Thus, analysts have generally viewed threats of large-scale costs in response to an adversary launching major conventional or nuclear attacks against a country’s homeland to be more credible than threats meant to deter an adversary from committing small-scale attacks against the country’s homeland that cause limited damage, or to protect distant allies against attack.[79] [quote id="5"] The debate surrounding the 2018 Nuclear Posture Review shows that, just like during the Cold War phase of the U.S.-Russia nuclear competition, extended deterrence commitments remain a key challenge in formulating U.S. nuclear policy and strategy.[80] To some extent, echoes of the Nixon administration’s nuclear thinking — which was centered on its belief that the ability of the Soviet Union to respond to a large-scale U.S. nuclear attack with a devastating nuclear counter-attack against the continental United States had nullified the U.S. extended nuclear deterrent — continued to reverberate during the Clinton and Obama administrations.[81] A declassified and heavily redacted Nuclear Supplement to Joint Strategic Capabilities Plan For FY 1996 suggests that some form of escalation control and limited nuclear options were retained in Department of Defense planning.[82] Though the Obama administration sought to downplay the role of nuclear weapons in U.S. national security strategy and to elevate the role of non-nuclear capabilities, it nevertheless insisted that U.S. nuclear forces “be postured and planned” so that the “United States should have a wide range of effective response options available to deter potential regional threats.”[83] In sum, because U.S. extended deterrence commitments generate a wide range of foreseeable and unforeseeable strategic and operational problems for U.S. planners and decision-makers, analysts should ensure that such problems are incorporated into their assessments as much as practicable, and not simply assume the problems will fail to materialize and complicate future U.S. military operations. Limited Nuclear Wars Are Possible Analysts can neither foresee the full range of circumstances that will factor into an adversary’s decision to be the first to use nuclear weapons in support of a military campaign, nor can they predict the circumstances that would shape a response. Therefore, analysts should not rule out the possibility of limited nuclear use, whereby an adversary’s use of nuclear weapons is not designed to destroy or overthrow the government of its opponent.[84] Instead, they should plan for such a possibility and think about how U.S. general purpose and nuclear forces would conduct sustained combat operations in an environment defined by the constant threat of nuclear weapons use as well as the actual intermittent use of such weapons.[85] Perhaps most important, the open-source literature indicates that the Russian military believes that limited nuclear wars are indeed possible. According to Dave Johnson, an analyst in the NATO International Staff Defence Policy and Planning Division, Russian military writings suggest “a role for nuclear weapons, including their limited use, in wars of various scales and intensities.”[86] One scenario that has become salient in discussions about a possible U.S.-Russian nuclear conflict is a Russian invasion of one or all of the Baltic states of Estonia, Latvia, and Lithuania, all of which are NATO members.[87] In a 2016 Center for American Progress table-top exercise looking at a short-warning Russian invasion of the Baltic states, participants recommended that U.S.-NATO forces continue to wage a conventional campaign rather than employ nuclear weapons to halt or reverse the Russian offensive.[88] Russian military documents and the published works of Russian military authors, however, suggest an alternative scenario wherein Russia conducts limited nuclear escalation — perhaps against U.S. military targets on European territories or in the littoral waters — in defense of gains it has made and to thwart U.S. intervention. In other words, Russia would extend its nuclear umbrella over seized territory to shore up its fait accompli against a NATO counter-attack.[89] In response to Russia’s nuclear use in the European theater, the onus would be on the United States to refrain from a nuclear response; to conduct a nuclear strike that the Russians might perceive as equivalent to their own, thereby perhaps lessening the pressure for Russian escalation; or to conduct a much larger set of nuclear strikes against military targets, which the Russians might see as highly escalatory.[90] In the Baltic states fait accompli scenario, it would be challenging for U.S. and NATO forces to continue conventional operations without also conducting supporting nuclear strikes to re-establish intra-war deterrence of Russian nuclear use. Discounting the possibility of the limited use of nuclear weapons could exclude numerous plausible military scenarios from being studied in the effort to determine whether U.S. military forces are adequately prepared for the use of nuclear weapons in a conflict. A Nuclear Revolution? Disagreements About Deterrence and Strategic Stability In order for any analysis of nuclear competitions to be meaningful to Defense Department planners and national security policymakers, it should be based on empirical data as much as possible. However, the dearth of adequate information on how each competitor views its standing in a nuclear competition against the United States and the potential effectiveness of its ways and means to achieve its objectives might lead some analysts and policymakers to fall back on a small collection of social scientific theories and models of the military requirements of deterring nuclear weapons use or of achieving war aims, such as the “nuclear revolution” perspective or the “superiority-brinksmanship synthesis theory.”[91] They should be cautious in surrendering to that temptation at the early stages of their research and analysis. The discussion so far suggests a divergence between the nuclear revolution school — the main school of nuclear thought in academia — and the strategic-analytic framework discussed in this paper. Although it is outside the scope of this article to close the gap between these two approaches, it is important to highlight some of the areas of disagreement and concern about deterrence requirements and the issue of strategic stability, as well as with how the United States could best develop its nuclear capabilities and nuclear posture to achieve its national security objectives.[92] Analysts adopting the strategic-analytic framework discussed in this article should be mindful that social scientific theories and models — by simplifying complex interactions of human, organizational, and inter-state behaviors in a quest for parsimonious explanations and predictive power — do not explain or help analysts understand the exceptions to the models that are found in histories of military competitions. It is these exceptions — the complexities and nuances reflected in evolving technologies, military operational concepts, and doctrine; the rise and fall of influential national security organizations; and new decision-making processes — that might be critical to understanding areas of potential U.S. leverage in a nuclear competition. Most important, the early adoption of some theories or models could result in the analyst foreclosing promising avenues of investigation, such as how U.S. competitors actually assess the nuclear balance and whether they would be deterred from initiating war to achieve their objectives. Therefore, while social scientific theories and models can offer insights and intriguing perspectives, strategic analysts should approach them with a skeptical eye.[93] In brief, the leading proponents of the nuclear revolution school, Robert Jervis and Charles Glaser, argue that under the condition of mutual assured destruction, wherein each nuclear competitor’s major population centers are vulnerable to annihilation, the likelihood of one side attacking the other is low and the quest for capabilities that would allow a disarming first strike is therefore futile. Moreover, because neither competitor can spare its population from serving as a hostage, the competitor willing to accept greater risk in a crisis or conflict will prevail.[94] Political outcomes, according to this school of thought, will be based on a competition in risk-taking rather than the nuclear balance.[95] [quote id="6"] Critics have countered, however, that the nuclear revolution school does not explain nuclear reality.[96] Keir Lieber and Daryl Press argue that through technological change and innovative military operational concepts, nuclear competitors can put one another’s seemingly invulnerable retaliatory forces in jeopardy. They further note that the United States has invested heavily in capabilities to undermine the survivability of its competitors’ forces.[97] Brendan Green and Austin Long, using declassified sources, contend that Soviet leaders during the latter half of the Cold War believed that mutual assured destruction was tenuous due to U.S. competitive pressure on the Soviet nuclear force structure and posture.[98] In addition, Matthew Kroenig uses his “superiority-brinksmanship synthesis theory” to argue that advantages in the nuclear balance increase a competitor’s willingness to engage in the competition in risk-taking. In contrast, an inferior nuclear competitor is less likely to run great risks and initiate military aggression against a superior competitor.[99] Taken together, these critics of the nuclear revolution school assert that nuclear advantages are achievable and do matter to political outcomes. Several areas of tension between the nuclear revolution school and its critics come to the surface in discussions of how the United States can use nuclear forces to maintain its overseas defense commitments to allies and deter both nuclear and non-nuclear attacks on their homelands. First, to enable the United States to demonstrate its resolve in support of the defense of its overseas interests and enhance its bargaining position with an adversary, the nuclear revolution school favors small-scale nuclear strikes against nonmilitary targets, such as economic and industrial assets, or even demonstration strikes against remote, unpopulated geographic areas simply to show resolve, rather than nuclear strikes against military targets, especially nuclear forces.[100] Correspondingly, the school asserts that under the condition of mutual assured destruction and in line with the logic of deterrence by punishment, the costs of counterforce strikes actually result from harm caused to the adversary’s population, not from the loss of military capabilities. Moreover, according to this school of thought, U.S. counterforce capabilities could end up encouraging escalation. In contrast, Elbridge Colby, who served as deputy assistant secretary of defense for strategy and force development when the 2018 National Defense Strategy and Nuclear Posture Review were published, contends that small-scale nuclear strikes against military targets, such as conventional forces, could enable the United States to demonstrate both resolve and restraint.[101] Colby suggests that an adversary might see a difference between U.S. strikes against military forces that weaken its ability to achieve its objectives, and strikes against targets that might result in additional harm to civilians. If so, that difference could allow the United States to shift the burden of escalation onto the adversary. If the adversary were to assess the nuclear balance and recognize this potential outcome, it might be dissuaded from initiating a conflict in the first place. The nuclear revolution school overlooks this possibility. Second, and related, the nuclear revolution school sees little value in retaliating in kind against military targets following an adversary’s counterforce attack for several reasons: First, destroying forces while bargaining under the condition of mutual assured destruction does not inflict substantial costs on the adversary (assuming the forces are not near population centers); second, small-scale attacks against nonmilitary targets do inflict costs while also conveying U.S. restraint and the implicit promise of future costs if the adversary does not reciprocate this restraint; finally, attacking the adversary’s nuclear forces sends a much less clear message in terms of demonstrating restraint and the promise of future costs, as there is little logic to attacking redundant nuclear forces when the adversary will retain a survivable nuclear retaliatory capability.[102] Using the strategic-analytic framework, however, an analyst cannot rule out a priori the possibility that adversary leaders would perceive circumstances differently from how U.S. leaders perceive them. Indeed, the analyst following this framework would seek empirical evidence of how the adversary assesses the loss of military capabilities compared to the loss of a certain portion or demographic sector of its population, and how it conceives of restraint and escalation in the use of force. For example, empirical research might uncover that adversary leaders would likely interpret American ICBMs en route to their country as more provocative — potentially eliciting a prompt nuclear response against the U.S. homeland — than the use of U.S. nuclear freefall bombs delivered by aircraft in a conflict far from U.S. territory. Thus, the types of weapons employed might be important in demonstrating U.S. restraint and in manipulating the adversary’s thresholds for escalation.[103] Third, the nuclear revolution school argues that maintaining significant counterforce capabilities to help limit the damage to one’s homeland is dangerous because it reduces strategic stability.[104] Strategic stability is usually used in U.S. nuclear policy debates to mean that the mutual vulnerability of each competitor’s population and the mutual invulnerability of deterrent forces would eliminate any incentive to initiate an attack against the other’s national security interests during a crisis.[105] This core concept undergirding mutual assured destruction calls for the United States to eschew nuclear capabilities that would support large-scale counterforce targeting in an extended deterrence scenario and to limit damage to the U.S. homeland. As discussed above, however, the threat of a major nuclear response following an attack on a competitor’s homeland is generally judged as more credible than the threat of such a response following an attack on its allies. Gaining insight into the adversary’s assessment of U.S. capabilities, credibility, and resolve might lead analysts to look into whether instability that favors the United States in a competition (e.g., U.S. counterforce capabilities to increase the vulnerability of an adversary’s nuclear forces) might enhance the U.S. ability to deter aggression against its allies.[106] Furthermore, in light of the possibility that America’s adversaries could be risk-prone or could miscalculate U.S. resolve and capabilities, U.S. counterforce capabilities might serve as a hedge. The last and perhaps most fundamental disagreement between the nuclear revolution school and its critics when it comes to understanding nuclear competitions is that the nuclear revolution school turns a blind eye to investigations into the historical preferences of the relevant organizations that provide input or make decisions about nuclear capabilities and posture. [107] In contrast, the strategic-analytic framework described in this article encourages analysis of competitors’ internal decision dynamics, research and development efforts, and procurement programs to discern key factors underlying current and evolving states of the competition. Such analysis, in the case of the Soviet nuclear buildup during the Cold War, for example, might have uncovered the different roles played by Soviet civilian leaders, senior military leaders, and the Soviet defense industry in making decisions about nuclear forces and strategy.[108] As Caroline Milne found in her study of the perceptions of mutual vulnerability within the U.S.-Soviet Union nuclear competition and the U.S.-China nuclear competition,

mutual vulnerability can be very difficult for (at least two sets of) nuclear rivals to accept in perpetuity. For a variety of reasons, it is much preferable to try to solve or at least ameliorate this strategic dilemma. Accordingly, while theories about the stability of reciprocal second-strike capabilities may be elegant, they presume a lack of agency that participants will find challenging to resign themselves to.[109]

The takeaway is not that social scientific theories and models are worthless. It is that analysts seeking to understand the character of future warfare and a nuclear competition should emphasize a wide-ranging investigation and empirical evidence — such as U.S. and competitors’ military capabilities, targeting policy, doctrine, and concepts of operations — rather than rely on social scientific theories that tend to prematurely guide research and analysis into an area of limited breadth and depth — an area that might keep the analyst from considering key factors that could shape the balance of nuclear forces as well as perceptions of that balance. Declaratory Policies and Published Doctrine Are of Limited Predictive Value Incredible as it may seem, even U.S. analysts with the requisite foreign language skills can hold divergent views about a competitor’s policy documents and doctrinal texts. Thomas Christensen and Gregory Kulacki, for example, both trained in Mandarin Chinese, interpret the 2004 edition of The Science of Second Artillery Campaigns (the Second Artillery being the predecessor to the People’s Liberation Army Rocket Force) in starkly different ways.[110] Christensen takes a much less sanguine view of the document’s implications for Chinese nuclear escalation in what has, thus far, been a conventional conflict than Kulacki, who is adamant that the text proscribes China’s first use of nuclear weapons. Kulacki maintained this more optimistic view of Chinese nuclear restraint when the Chinese Academy of Military Sciences published a new edition of The Science of Military Strategy.[111] And yet, even if analysts did agree, what an adversary claims it would do in a crisis or during wartime might only be as solid as the paper it is written on. As Christensen recognizes, competitors cannot be assured that peacetime declaratory policies will persist during the stressful and violent circumstances of conflict. The same thing can be said about relying on published military doctrine.[112] In 1975, Secretary of Defense James Schlesinger noted that neither national leaders nor military forces are constrained by doctrine in a wartime environment.[113] Because the nuclear thresholds and practices of potential adversaries are always shrouded in uncertainty, it would behoove U.S. analysts to conduct sensitivity analyses to see how their findings might change. Other perceptive analysts of Russian and Chinese nuclear thinking have written about the ambiguities and vague expressions found in the two countries’ nuclear declaratory policies. With Russia planning — if not fully funding — the deployment of a strategic weapon arsenal consisting of long-range conventional precision-strike weapons, nonstrategic nuclear weapons, and strategic nuclear weapons, the objective seems to be to give Russian leadership maximum flexibility and a range of options to deal with both anticipated and unforeseen contingencies.[114] Russia’s 2014 military doctrine states that Russia reserves the right to respond with nuclear weapons when “the very existence of the state is threatened.” However, because it does not list the criteria by which Russian leaders would assess threats to the state, there may be multiple U.S.-NATO conventional courses of action — including rolling back the Western Military District’s integrated air defense system or launching an air-missile raid against the Northern Fleet’s naval facilities on Russia’s Kola Peninsula — that could create perceptions of a growing threat against the Russian state and elicit different types of Russian military reactions. [quote id="7"] China, on the other hand, has officially maintained a no-first-use pledge since it became a nuclear power in 1964. However, that pledge has not escaped the criticism of Chinese strategists.[115] For the past ten years, scholars have noted a debate within Chinese military circles “about whether to discard or place conditions” on Beijing’s declaratory policy.[116] Apparently, concerns over the effects of conventional strikes against China’s nuclear deterrent generated the debate. Some Chinese writers have argued for increasing the pledge’s ambiguity to create additional uncertainty in the minds of China’s adversaries. Others have suggested that China conduct a nuclear counter-attack in response to an enemy’s conventional counter-nuclear attack. More recently, analysts have reasoned that the continued publication of articles in China arguing for official exemptions to the no-first-use pledge reflects the authors’ frustration that China is not leveraging the potential political effects of its nuclear forces.[117] As in the Russian military literature, so-called “warfighting concepts” are found in Chinese military writings: for example, the possibility of nuclear strikes of varying scale against an array of military, political, and economic targets.[118] In the Chinese military literature, according to a 2017 RAND study, “warfighting concepts” refer to “an approach that involves conducting multiple waves of strikes of various scales against different types of targets in a nuclear conflict of extended duration, designed to control escalation or to compel an end to hostilities on favorable terms.”[119] What is potentially troubling for the U.S. military is that the continuing debate within China over the merits of its no-first-use pledge could interact with these warfighting concepts and result in China’s leaders sanctioning the first use of nuclear weapons during a conventional conflict with the United States. This situation might be more likely were China losing a high-stakes conflict with the United States, perhaps failing to secure beachheads on Taiwan due to a U.S. military intervention.[120] While far from certain, the central ingredients seem be in place to create the wartime circumstances that could pressure China to ostensibly violate its declaratory policy and use nuclear weapons first.[121] First, Chinese military writings emphasize the benefits of seizing and retaining the initiative throughout a conflict.[122] Second, U.S. analysts have noted that China likely judges computer network attacks and counter-space operations to be warranted early in a conflict to paralyze the enemy’s command-and-control system.[123] Third, one of the guiding principles, or fundamental doctrinal tenets, for the People’s Liberation Army Rocket Force is “key point counter-attacks” to reduce the enemy’s will to fight. Taken in combination, these factors suggest, but do not prove, that Chinese leaders and military planners could find reason to justify China using nuclear weapons first to obtain an advantage over the United States in a conflict. In short, because policies developed under peacetime conditions can change quickly once policymakers confront the reality of a crisis or war, countries’ nuclear declaratory policies are poor guidelines for defining the scope of an analysis of a nuclear competition. Victory Is Possible in Some Nuclear Wars The preceding sections demonstrate that, like conventional warfare, nuclear warfare can come in all shapes and sizes. As is always the case, the meaning of victory in war is shrouded in politics.[124] Leaders will define what “victory” is in terms that they deem favorable in order to bring an end to hostilities, but even an authoritarian regime will want the public to support the basis for the cessation of hostilities to avoid domestic political upheaval. The possibility of a limited nuclear war means that the world might only see small-scale use of nuclear weapons — perhaps only a single detonation — before belligerents cease military operations and de-escalate tensions. In light of the psychological shock, physical damage, and military effect that just a handful of nuclear strikes might cause, one or more belligerents may very well acquiesce to the political demands of the adversary that launched nuclear weapons. This acceptance could constitute a political victory in the eyes of the adversary’s leaders and body politic, as well as in those of the opponents. On the other hand, nuclear use could result in belligerents changing their war aims and modifying their campaign plans accordingly. In the end, because different forms or types of victory may be achievable, analysts should not buy into the mantra that “no one wins a nuclear war” and allow it to shape their assessments of nuclear competitions.[125]

Planning a Road Trip through Terra Incognita

There is too much uncertainty surrounding potential crises and conflicts between the United States and nuclear adversaries for analysts to provide iron-clad assurances that a particular U.S. nuclear or regional defense posture will deter acts of aggression or establish a ceiling on nuclear escalation. Even former Secretary of Defense William Perry, a prominent advocate of disarmament measures and the non-use of nuclear weapons, acknowledged that “we have no experience with escalation in a nuclear war, and we have no way of being confident what the ultimate outcome would be of a first use of nuclear weapons.”[126] Likewise, Jervis, a critic of U.S. “escalation control” planning, has noted that analysts and strategists have little empirical basis for guiding nuclear strategy. The United States is the only state that has conducted nuclear strikes — and it was against a non-nuclear opponent. “Our knowledge of nuclear deterrence,” according to Jervis, “is largely deductive.”[127] Yet, the deductions and parsimonious models that some analysts rely upon are unmoored from the operational and political challenges surrounding the initial use of nuclear weapons in a future conflict and the threat of their continued use as that conflict potentially develops into a protracted war.[128] The preceding sections, in combination, have contended that warfighting capabilities are inextricably foundational to protecting U.S. overseas interests and maintaining and fulfilling extended deterrence commitments. The only way to avoid the connection between warfighting capabilities and deterrence of a wide range of adversary actions and do minimal harm to U.S. vital interests is for the United States to abandon its alliance commitments and adopt a minimum deterrence posture solely to safeguard the U.S. homeland.[129] Perhaps recognizing the challenges that extended deterrence poses for U.S. policymakers and strategists, in 2010 several analysts affiliated with the U.S. Air Force called on the United States to withdraw its extended deterrence commitments.[130] Needless to say, while the United States plans on retaining disparate overseas defense commitments, analysis that fails to work through seemingly intractable military problems and strategic challenges — while only providing assertions of how future conflicts will unfold and how different leaders will make decisions about the use of nuclear weapons — cannot be justified. Such analysis is clearly not useful to informing debates and decisions about future U.S. nuclear capabilities and posture. Recall President Dwight Eisenhower’s thoughts on the value of diligent planning. In a speech at the National Defense Executive Reserve Conference in 1957, he stated,

Plans are worthless, but planning is everything. There is a very great distinction because when you are planning for an emergency you must start with this one thing: the very definition of ‘emergency’ is that it is unexpected, therefore it is not going to happen the way you are planning. So, the first thing you do is to take all the plans off the top shelf and throw them out the window and start once more. But if you haven't been planning you can't start to work, intelligently at least. That is the reason it is so important to plan, to keep yourselves steeped in the character of the problem that you may one day be called upon to solve—or to help to solve.[131]

Our Understanding Of Nuclear Crises

In this study, we employ the definition of crisis used by the multi-decade International Crisis Behavior project: A nuclear crisis is an interaction between two nuclear-armed states in which there is a “change in type and/or an increase in intensity” of disruptive or hostile behaviors with a “heightened probability of military hostilities” that “destabilizes their relationship” and begins with a “disruptive act or event.”[4] Studying nuclear crises is fraught with the same methodological challenges as studies of other crises short of war, including deciding which cases to examine, grappling with selection effects, and identifying appropriate counterfactuals.[5] Despite these challenges, the significance of nuclear crises to contemporary international politics is widely understood. Matthew Kroenig, for example, writes that “the nuclear crisis [is] the primary arena in which nuclear-armed states settle important international disputes.”[6] Indeed, for many, the replacement of great power wars with nuclear crises is one of the defining features of the post-1945 international system.[7] Despite a shared recognition of the importance of nuclear crises, there is little agreement on the dynamics that underpin them. Scholars tend to view “nuclear crises” as a group of events that share an underlying logic, but disagree about what that logic is.[8] For example, according to advocates of the theory of the “nuclear revolution,” nuclear weapons suppress the temptation to escalate crises at all levels. The destructive capacity of nuclear weapons casts a long shadow over all interstate crises, restricting the range of behaviors that states can reasonably engage in.[9] As John Mearsheimer notes, “Nuclear weapons, because of the horror associated with their use, really are the ultimate deterrent” and make “states more cautious about using military force of any kind against each other.”[10] For scholars of the nuclear taboo or advocates of the “stability-instability paradox,” however, the difficulty of credibly threatening to use nuclear weapons, and the bright line distinguishing nuclear use from non-nuclear use, ought to reduce the influence that nuclear weapons have within a crisis.[11] Recent empirical scholarship also suggests that crises operate according to a certain logic, while disagreeing as to what that logic is. For example, Kroenig argues that a state with nuclear superiority is more likely to achieve its goals in a nuclear crisis, while Todd Sechser and Matthew Fuhrmann conclude that nuclear weapons do not help states compel others to do what they want during crises.[12] This disagreement is concerning for several reasons. First, policymakers (or anyone, for that matter) seeking to understand how nuclear crises unfold, how dangerous they might be, and how one might pursue a state’s political interests within such a crisis, will struggle to gain insights from a literature that offers contradictory findings and implications. Second, by seeking a single logic that explains nuclear crises, existing work downplays the variety among them.[13] A simple historical reading, for example, suggests profound differences between the dynamics underpinning the 1995 Taiwan Straits crisis, the various Berlin crises, the war in Angola, and the 1970 Cienfuegos submarine base crisis, all of which are typically identified as “nuclear crises.”[14] Indeed, common understandings of the different dangers involved in different crises — that the Cuban Missile Crisis, for example, was the “most dangerous” Cold War crisis — reflect a heterogeneity that existing theories do not account for.

Models of Nuclear Crises

In this section, we describe two variables that affect the ways in which nuclear crises unfold: the strength of incentives to use nuclear weapons first in a crisis, and the degree to which the actors involved are able to control escalation of the crisis. These two variables are determined by the objective features of a given crisis, although we incorporate the possibility that the crisis participants’ perceptions of these variables may diverge from reality in ways that influence how they behave. Incentives for first nuclear use and the degree of controllability are well understood to affect how a nuclear crisis plays out, however, they have not previously been incorporated into a single framework that sheds light on the diversity of nuclear crises. Examining these two dimensions leads to four possible “ideal type” models of nuclear crisis: the “staircase” model, the “brinkmanship” model, the “stability-instability” model, and the “firestorm” model. These models, in turn, correspond to prominent ways that scholars and analysts have thought about nuclear crises. The framework demonstrates that different models of nuclear crisis should be expected to operate under different circumstances. This insight holds important implications for how to understand existing scholarship on nuclear crises, as well as variation among these crises across time. Table 1 summarizes the indicators of the variables that we examine in the case studies below. Each of these variables is itself the aggregation of other variables. Grouping them in this way, however, allows us to impose some conceptual order on the ways in which nuclear crises can vary, and thus begin to shed light on the diversity of this class of events. Table 1: Indicators of the Two Variables [table id=13 /] The first variable we examine is the extent to which either side faces incentives to use nuclear weapons first in a crisis. This variable asks whether the crisis is one in which either side would gain substantial advantages from using nuclear weapons first. Such incentives may emerge in at least two distinct ways. First, the dynamics of a possible nuclear war may mean that first nuclear use could meaningfully affect the final outcome of the conflict. In particular, if there is a large disparity in capabilities between the nuclear forces of the participants in the crisis, there will be stronger incentives for both sides to use nuclear weapons first. For the weaker state, having a vulnerable and small nuclear force may generate doubts about the ability of that state’s nuclear arsenal to survive a first strike, thereby creating pressure for states to “use them or lose them,” and incentivizing aggressive nuclear postures and first nuclear use. As Peter Feaver argues, a state with a vulnerable nuclear arsenal has an “incentive to posture its forces for an early use in a crisis, before its nuclear option is curtailed.”[15] For the state with the more powerful arsenal, meaningfully limiting damage through engaging in offensive nuclear counterforce missions might be tempting, as might be the possibility of a splendid first strike — the ability to completely take out an opponent’s nuclear capabilities.[16] Crises characterized by significant nuclear asymmetry — in particular, where one side plausibly lacks a secure second strike capability — will therefore feature greater incentives to use nuclear weapons first than crises characterized by a greater degree of symmetry, in which meaningful damage limitation and/or a splendid first strike are less plausible. Second, nuclear first use may be threatened as part of the bargaining process within a crisis or war. Crises in which one (or both) states has a nuclear posture designed to credibly threaten the first use of nuclear weapons — what Vipin Narang refers to as an “asymmetric escalation” posture — will be characterized by greater incentives to use nuclear weapons first.[17] [quote id="1"] These two factors contributing to incentives for first use are objective features of a given crisis. However, they can only affect the dynamics of a crisis if they are perceived to exist by the leaders involved. If leaders do not perceive that first use could provide significant political advantages in a crisis or conflict, those incentives will not affect crisis dynamics. We therefore code crises in which either side lacks a secure second strike capability and/or has an asymmetric escalation posture and in which one or both leaders perceive that nuclear first use may offer substantial political benefits within the crisis as being characterized by incentives to use nuclear weapons first. That is to say, crises in which either side has and perceives incentives for nuclear first use are coded as having incentives for first nuclear use. The second dimension is the extent to which a crisis is controllable by the actors participating in the crisis. Controllability refers to the ability of leaders to make conscious and strategic decisions to determine the level of escalation in a given crisis. It is important to note that crisis controllability does not refer to the level of escalation that occurs. A crisis can escalate to (and beyond) the nuclear threshold in a controlled fashion, i.e., in a process in which each leader makes a conscious and deliberate strategic calculation to escalate at every stage. Controllability instead refers to the process by which escalation occurs — to whatever level.[18] We code crisis controllability on the basis of a number of features of a crisis. These features are not intended to be an exhaustive list of factors contributing to crisis controllability, but rather a series of indicators that can be observed and that influence crisis controllability in important ways. First, different states have different command and control arrangements, which means that leaders exercise different levels of control over nuclear use.[19] For example, a crisis in which both leaders have exclusive authority to make decisions about nuclear use, and robust institutions exist that enforce that authority even in crisis situations, thereby minimizing the risk of accidental or inadvertent use, is more controllable than one without such checks. Second, clear and mutually understood red lines for nuclear use, if they exist, can increase controllability, since they reduce the likelihood that a state will accidentally cross another state’s red line for nuclear use.[20] Third, if a state’s conventional forces are likely to target forces relevant to the adversary’s ability to use nuclear weapons, or if forces relevant to conventional and nuclear operations are likely to interact with each other in a crisis or military operation, crisis controllability will likely be lower.[21] Fourth, states have varying abilities to communicate with each other during crises: A crisis in which the two states have well-established avenues through which to communicate, or in which a third party can reliably convey information between two states in a crisis, may be more controllable than crises in which states communicate through unreliable or ad hoc channels or exclusively through public signaling. Further, the ability to communicate is not simply institutional: For example, certain pairs of leaders may better understand or empathize with each other than others, improving crisis controllability.[22] It is worth noting four potential objections at this point. First, it might be objected that the two variables are not independent of each other. For example, one reason why a crisis might lack controllability is if there are incentives to use nuclear weapons first and battlefield commanders are therefore given pre-delegated authority to use nuclear weapons.[23] However, the relationship between these two variables is not determinative (as discussed above, there are many other sources of crisis controllability), and one can conceive of crises that are controllable — where there is firm control over nuclear assets, clear red lines, etc. — but in which incentives to use nuclear weapons first are nonetheless strong. These two dimensions are therefore appropriately considered separately because each exerts an independent effect on the character of nuclear crises. A second potential criticism is that neither variable accounts for how high the stakes of the crisis are: Shouldn’t the stakes involved affect the way a crisis plays out? As we discuss below, the stakes of the crisis can be incorporated within our framework. This is because we expect that states would be willing to enter different types of crises to protect different interests. For example, because stability-instability crises pose relatively little risk of nuclear escalation, we expect that policymakers will be more willing to enter them even over relatively unimportant stakes. By contrast, firestorm crises have a much higher risk of nuclear escalation, and we therefore expect that policymakers would only enter such crises if the most vital national interests were at risk. This has implications for understanding existing, contradictory empirical findings, which we discuss more fully in the following sections. Third, some might ask if these are the only two variables that matter. Probably not. As mentioned above, this framework represents a first step in exploring the variation among nuclear crises, but additional variables likely affect how individual crises play out, including perceptual, bureaucratic, normative, and technological variables. Exploring whether adding additional variables sheds greater light on the heterogeneity of nuclear crises would be a valuable avenue for future research and one that we return to in the conclusion. A fourth objection could concern the fact that these variables are determined by objective features of a given crisis, which may be imperfectly known or misperceived by participants at the time of the crisis: Is this not problematic for our analysis? The framework we offer allows for an initial disaggregation of nuclear crises that permits us to begin exploring their diversity and includes leaders’ perceptions of incentives for nuclear first use. This represents an advance on prior literature, but is only a first step. While these objective features of the crisis should be expected to exert a profound influence on the nature of the crisis, even if they are not known or fully understood by policymakers, further incorporation of policymakers’ perceptions and misperceptions could add richness to our framework and would be a productive next step. Indeed, policymakers’ misperceptions of (or uncertainty about) these variables may add explanatory power to our framework by allowing us to better account for miscalculations that states make within crises. For example, Pakistan might have been less willing to provoke the Kargil War had it known that the crisis would be primarily determined by the conventional balance of forces, which favored India. As shown in Figure 1, these two variables create a conceptual space within which existing models of nuclear crisis can be situated. We highlight four models that correspond to the quadrants of this conceptual space. Of course, each model represents an “ideal type.” More types of crisis exist in the conceptual space between these four possibilities. Figure 1: Models of Nuclear Crises

The four models we identify offer very different interpretations of nuclear crises. Indeed, they suggest different answers to four basic questions about such crises: How likely is nuclear use within a crisis? Does the conventional or nuclear balance have a stronger effect on the outcome? Is nuclear superiority valuable within a crisis? And how feasible is signaling within a crisis? Table 2 summarizes the differences between these four models. The following sections of the paper describe these differences in more detail. Table 2: Answers to Key Questions About Nuclear Crises [table id=16 /] Stability-Instability Crises Crises that are controllable and have limited incentives for nuclear first use are “stability-instability” crises. This model approximates Glenn Snyder’s view of nuclear weapons. Snyder famously suggested that “the greater the stability of the ‘strategic’ balance of terror, the lower the stability of the overall balance at its lower levels of violence. …Thus firm stability in the strategic nuclear balance tends to destabilize the conventional balance.”[24] Jervis describes the same idea: “To the extent that the military balance is stable at the level of all-out nuclear war, it will become less stable at lower levels of violence.”[25] We should not expect nuclear powers, according to this view, to fight all-out nuclear wars, but they may engage in more lower-level conflicts. Similarly, for scholars who argue that a powerful taboo inhibits nuclear use, crises between nuclear states will be characterized by a clear prohibition against nuclear use, and relative freedom to engage in conventional escalation.[26] The possibility of nuclear escalation within stability-instability crises is low. Even in stability-instability crises that escalate significantly, actors are likely to remain confident that the nuclear threshold will not be breached. Since the risk of nuclear use is low and relatively constant across crises of this sort, we expect the nuclear balance to be unrelated to the outcomes of stability-instability crises, and nuclear weapons will not regularly enter the calculations of leaders in these crises. The outcomes of stability-instability crises will instead be determined by other factors, such as the conventional military balance. Finally, signaling is feasible within stability-instability crises, since the two sides can calibrate their forces and level of conventional escalation to send signals about their political interests. However, since nuclear use is viewed by both sides as unlikely, making nuclear threats will not generally be credible within this type of crisis. Stability-instability crises are therefore relatively safe, at least in terms of the risk of nuclear escalation, and we therefore expect to see statesmen being more willing to enter this type of crisis than others that pose greater risk of nuclear escalation. We also expect stability-instability crises to be relatively common within datasets of crises, a point that has implications for interpreting contradictory empirical findings in existing literature. We argue below that the recent Doklam crisis between India and China is best categorized as a stability-instability crisis. Staircase Crises We term a crisis that is controllable but in which there are incentives for nuclear first use as a “staircase” crisis. This model approximates the view of escalation that Hermann Kahn offers in his book, On Escalation, and emphasizes deliberate, calibrated escalation. Despite the deliberate and conscious way in which escalation occurs according to this model, escalation to and beyond the nuclear threshold is possible given that states may have incentives to use nuclear weapons first, or to use them in a deliberately limited way. In Kahn’s formulation, the first use of nuclear weapons can serve a range of political purposes, including “redressive, warning, bargaining, punitive, fining, or deterrence purposes.”[27] Even apparently accidental nuclear use may, in fact, be deliberate, resulting from a desire to “give the impression that [nuclear] use was unintentional.”[28] In short, according to the staircase model of nuclear escalation, deliberate first nuclear use is highly plausible. [quote id="2"] What determines victory in a staircase crisis? All staircase crises have a nuclear dimension: Escalation to the nuclear level is always feasible and may be deliberately chosen, making nuclear use plausible. However, we expect the degree to which nuclear weapons weigh on the minds of participants in staircase crises to vary according to the level of escalation reached: Because of the significance of nuclear use and the many less escalatory options states typically have available to them before resorting to this extreme level of force, a staircase crisis is unlikely to suddenly escalate across the nuclear threshold without prior conventional escalation. For this reason, staircase crises that do not escalate close to the nuclear level may be determined almost entirely by the conventional balance of power, while those that escalate closer to, or beyond, the nuclear threshold are likely to be determined more by the nuclear balance. Because crises that operate according to the staircase model are, by definition, characterized by high levels of controllability, escalation and de-escalation within such a crisis is possible: Escalation levels can be controlled and calibrated, and signaling by using both nuclear and conventional forces is feasible. Lastly, because a staircase crisis may be determined by the nuclear balance, and because limited nuclear use is plausible, both nuclear superiority and limited nuclear options may well be of value to states engaging in a crisis of this sort. Indeed, calls for “escalation dominance” by policymakers — that is, the ability to deter an adversary at every rung of the escalation ladder — draw implicitly on the staircase model since they assume that escalation occurs as a conscious and strategic choice at each level of escalation. Staircase crises are dangerous and states are therefore unlikely to enter them over trivial matters, although they may be willing to enter them when important national interests are at stake. We would therefore expect staircase crises to be rarer than stability-instability crises, but more common than firestorm crises. We argue below that the 1999 Kargil War between India and Pakistan is best categorized as a staircase crisis. Brinkmanship Crises We label crises that are characterized by limited incentives to use nuclear weapons first and low levels of controllability as “brinkmanship” crises. This model approximates the views of Thomas Schelling, who emphasized the political utility of “threats that leave something to chance” under circumstances in which deliberate first nuclear use is not credible.[29] Similarly, scholars of the “nuclear revolution,” such as Kenneth Waltz, Charles Glaser, and Robert Jervis, also view nuclear crises in this way, although such scholars tend to be more cautious than Schelling about the possibility of using the political leverage that comes from the manipulation of nuclear risk. In this model, states may take steps to escalate a conflict, but those steps are unlikely to involve deliberate first nuclear use, which is not typically credible in brinkmanship crises given low incentives to use nuclear weapons first. As Schelling argued, “There is just no foreseeable route by which the United States and the Soviet Union could become engaged in a major war.”[30] Similarly, for scholars of the “nuclear revolution” school, because achieving a reliable first-strike counterforce capability is extremely difficult compared to the relative ease of achieving a second-strike capability, the incentives for using nuclear weapons first in a crisis are small. States will not lose the ability to retaliate by delaying the use of nuclear weapons, and can still cause enormous destruction even after absorbing a first strike. The lack of incentives for nuclear first use, however, “does not mean that a major nuclear war cannot occur.”[31] Schelling describes the process of escalation as one in which “either side can take steps—engaging in a limited war would usually be such a step—that genuinely raise the probability of a blow-up. …What makes [these steps] significant and usable is that they create a genuine risk…that the thing will blow up for reasons not fully under control.”[32] For Schelling, this possibility is what gives nuclear-armed actors political leverage even in the absence of incentives for nuclear first use. For scholars in the “nuclear revolution” camp, the possibility of uncontrolled nuclear escalation is why nuclear-armed states should avoid challenging each other’s vital interests. What dynamics underpin a brinkmanship crisis? First, as with the staircase model, all brinkmanship crises involve some risk of nuclear escalation. However, nuclear escalation is only likely as part of a process of uncontrolled escalation. What determines the outcome of a brinkmanship crisis? Because the manipulation of the risk of uncontrolled escalation is the primary source of political leverage within brinkmanship crises, outcomes are determined by “competitions in risk taking” and by the “balance of resolve” rather than by the conventional or nuclear balance (the conventional or nuclear balance could affect crisis outcomes by affecting resolve).[33] Signaling and escalation are possible, but we should expect significant conventional escalation within brinkmanship crises to be accompanied by fear that uncontrolled nuclear escalation might occur. Nuclear crises of this sort are therefore dangerous for statesmen to enter into, but they may be willing to do so when the stakes are high, i.e., to secure important national interests. We should therefore expect that brinkmanship crises will occur less frequently than stability-instability crises, but more frequently than firestorm crises, as we discuss next. We argue below that the Cuban Missile Crisis unfolded according to this logic. Firestorm Crises We label crises where there are both incentives for nuclear first use and low levels of controllability as “firestorm” crises. A firestorm crisis is the most dangerous and volatile type of crisis: Both deliberate and uncontrolled escalation to the nuclear level might occur even in the absence of significant prior escalation. The fear of a firestorm crisis has played an important role in public discourse and policy discussions throughout the nuclear age. For example, the fear of nuclear “sneak attacks” had strong domestic political salience during the early years of the Cold War.[34] Indeed, early U.S. assessments of the political implications of nuclear weapons viewed them as offensive weapons that would be used to land the first blows of any potential third world war. The desire to prevent a “nuclear Pearl Harbor” was one motivation for the United States abandoning its isolationist tendencies in the aftermath of World War II. Similarly, “worst-case” scenarios in which “rogue states” acquire nuclear weapons draw on the possibility that irrational or religiously motivated states might attack other states out of the blue — for example, that Iran might seek to “wipe Israel off the map” if it acquired nuclear weapons. How do firestorm crises unfold? First, the possibility of nuclear escalation is high: A firestorm crisis could escalate at any moment and without significant prior escalation, which, in turn, encourages crisis participants to be deeply fearful and increases the temptation to take pre-emptive action. Signaling is likely to be difficult given the instability of such a crisis and the speed with which it can escalate. Indeed, crisis participants should be well aware that early blows in any crisis might in fact be nuclear. Because this type of crisis is prone to escalate to the nuclear level swiftly, the nuclear balance is likely to ultimately determine the outcome to a greater degree than the conventional balance. Thus nuclear superiority may be useful to states. Crises of this sort are extremely dangerous, and we therefore expect that statesmen will only enter them to achieve absolutely vital national interests. Because of these dangers, we also expect that firestorm crises will be the most rarely observed type of nuclear crisis. We argue below that future crises between the United States and North Korea would likely unfold according to this model’s logic.

Historical Crises: The Cuban Missile Crisis and the Kargil War

We first examine the utility of our typology using the 1962 Cuban Missile Crisis between the United States and Soviet Union, and the 1999 Kargil War between India and Pakistan. In each case, we analyze incentives for first nuclear use and crisis controllability to show which model of nuclear crisis best applies, and the insights that it provides into the crisis. We use these cases because both are widely considered among the most important in the history of nuclear crises, both involved national interests that participants considered important, both involved an attempted fait accompli by one side followed by efforts by the other to reverse it,[35] and both crises reached high levels of military escalation. Furthermore, recent work on nuclear crises explicitly seeks to account for the dynamics of these two cases with a single explanation.[36] As a result, we might expect that these two crises would be more likely than most pairs of nuclear crises to share similar dynamics. If we can show that even these two crises — ostensibly more similar than many others — differed in ways that our framework sheds light on, it would provide significant validation for our approach. The Kargil War The disputed region of Kashmir has been a source of friction between Pakistan and India since their partition in 1947.[37] Control over the territory is split, with a Line of Control (LoC) demarcating the territorial status quo. India has long viewed the territory as an integral part of the Indian Union, while the Pakistani government contends that Kashmir’s accession to India was unlawful and has sought the eventual “liberation” of Indian Kashmir. In May 1999, one year after Pakistan and India publicly tested nuclear weapons, the Pakistani North Light Infantry, backed by guerrillas, mounted an incursion along the LoC, with the aim of presenting India with a fait accompli.[38] Initial Indian attempts to dislodge Pakistani troops proved ineffective, and the Indian government granted Gen. Ved Prakash Malik, Chief of the Army Staff, the right to employ airpower in support of ground operations.[39] On May 26, the Indian military forces initiated a combined air and ground campaign resulting in intense combat.[40] By early July, Pakistan was on the brink of defeat. Pakistan’s Prime Minister, Nawaz Sharif, travelled to Washington D.C. to meet with U.S. President Bill Clinton, who demanded that Pakistan unconditionally withdraw and restore the ante bellum status quo. Sharif conceded to Clinton’s demands, calling for the withdrawal of all troops from the disputed region on July 12.[41] Coding the Kargil War The Kargil War was characterized by incentives to use nuclear weapons first. Specifically, Pakistan’s nuclear posture threatened first nuclear use in order to compensate for its relatively weak conventional military force.[42] Facing a conventionally stronger enemy, Pakistan had adopted a nuclear posture that integrated nuclear weapons into its military forces in order to credibly threaten a first strike against advancing Indian conventional forces.[43] At the time of the Kargil War, Pakistan had the capability to use nuclear weapons. The 1998 tests had confirmed its nuclear status, and by May 1999, Pakistan had credible delivery systems: several dozen tactical nuclear warheads that could be mated with missiles, a smaller number of short- and medium-range ballistic missiles, and delivery-capable aircraft.[44] Both Pakistani and Indian leaders recognized Pakistan’s incentives for nuclear first use. Upon the initiation of Indian air attacks, the Pakistani foreign secretary publicly warned New Delhi that his country “would not hesitate to use any weapons in [Pakistan’s] arsenal to defend [its territorial] integrity.”[45] According to Bruce Riedel, a senior adviser to Clinton, U.S. intelligence was aware that the Pakistani army was readying its nuclear-tipped missiles in preparation for an Indian attack across the border.[46] Indian leaders also understood Pakistani incentives for making the first nuclear move.[47] When Malik told Prime Minister Atal Bihari Vajpayee that opening a second front at the border might be militarily necessary, Vajpayee looked shocked and responded, “but General Sahib, they have a nuclear bomb!”[48] Indian National Security Advisor Brajesh Mishra confirmed this fear, stating that while the Indian leadership was “95 percent sure” that its army would not need to cross the LoC, the use of “nuclear weapons would have been risked if we did.”[49] Reports of Pakistani nuclear mobilizations exacerbated these fears. During the crisis, India received intelligence reports indicating Pakistani missiles were “being readied for possible launching,”[50] and the chief of the Indian army staff after the Kargil War, Gen. Sundararajan Padmanabhan, stated that Pakistan had “activated one of its missile bases and…threatened India with a nuclear attack.”[51] Because of these reports, some of India’s missiles were “dispersed and relocated,” and India’s nuclear forces placed on “Readiness State 3,” which involved the assembly and deployment of nuclear warheads near delivery vehicles.[52] [quote id="3"] Despite incentives for nuclear first use, the Kargil War was relatively controllable for four reasons: India’s strong command and control institutions, relatively clear Pakistani red lines that India did not seek to cross, a limited geographic zone of conflict that reduced the risk of conventional and nuclear forces interacting, and well-established avenues of crisis communication. This controllability was enhanced by the active involvement of the United States in the crisis, providing additional avenues of communication and clarifying the red lines of both sides.[53] Only Pakistan’s delegative command and control institutions indicate a lack of controllability in the crisis. First, consider Pakistani and Indian command and control institutions, which have contrasting implications for controllability. On the Pakistani side, delegative command and control increases the credibility of nuclear first use and thus increases the deterrent power of Pakistan’s nuclear weapons, but also raises the risk of accidental nuclear use and reduces crisis controllability.[54] Indian command and control, by contrast, increases the controllability of a crisis. Indian leaders, fearful of granting the military too much influence over nuclear matters, have consistently maintained high levels of control over the decision to use nuclear weapons. Indian nuclear weapons are maintained in a manner that limits inadvertent or unauthorized use: The civilian department of atomic energy controls fissile materials, while delivery vehicles are held in separate locations and controlled by the military.[55] Second, Pakistani red lines for nuclear use were relatively clear. Specifically, as long as Indian forces did not cross the LoC, the risk of Pakistani nuclear use would remain low. The Pakistani army’s director of strategic plans division, Khalid Kidwai, had publicly outlined scenarios in which first use would occur: “If India conquered a large part of Pakistan’s territory, destroyed a large part of its military forces, strangled Pakistan economically or caused large scale internal subversion in Pakistan.”[56] Former Pakistani President Pervez Musharraf claims that whenever he met with a foreign leader, “I asked him to convey my message…that if [Indian] troops took even a step across the international border of the LoC…it will not remain a conventional war.”[57] This message was well understood by Indian leaders. As we discuss further below, India was careful not to cross Pakistan’s key red line for nuclear use, even though it would have been to their military advantage to do so. Third, the limited geographic range of the conflict meant that the likelihood of nuclear and conventional forces interacting was low. While both sides took steps to increase the alert status of their nuclear forces, neither sides’ nuclear forces, nor the command and control centers necessary to use nuclear weapons, were close to the conflict zone. As long as India eschewed opening a second front in the war, or invading Pakistani territory, the possibility of Indian conventional forces placing Pakistani commanders under pressure to “use or lose” their nuclear assets was low. Fourth, the existence of official and back-channel negotiations between India and Pakistan, along with the involvement of numerous outside countries — the United States, China, Russia, France, the United Kingdom, and Saudi Arabia — seeking to facilitate a negotiated solution also enhanced controllability. Regular calls between Indian and Pakistani leaders, a hotline link between the two directors of general military operations, and the additional channels of communication provided by outside parties created many opportunities for de-escalation during the crisis.[58] Predictions The Kargil War was characterized by incentives for first nuclear use and high levels of crisis controllability, and is therefore best understood as a staircase crisis. Based on this assessment, what dynamics should we expect to see in the case? First, because the crisis did not come close to the nuclear threshold, we should expect that the conventional balance would determine the outcome of the war, rather than the nuclear balance or balance of resolve. Second, the primary danger of nuclear use should be expected to have come from deliberate first nuclear use rather than uncontrolled escalation. Third, signaling should have been feasible within the crisis.[59] As predicted, the conventional military balance does appear to explain the outcome of the conflict: Pakistan was on the verge of conventional military defeat when Pakistani leaders acceded to U.S. demands to withdraw their forces, and once India was able to build up its forces sufficiently, it experienced increasing success in pushing Pakistani forces back toward the Line of Control.[60] This occurred despite India restraining its conventional operations in various ways in order to prevent crossing Pakistan’s red lines for nuclear use. By contrast, and as anticipated by the framework we offer, neither the nuclear balance nor the balance of resolve appears to satisfactorily explain India’s ability to prevail in the crisis. The balance of resolve likely favored Pakistan given its consistently more risk-acceptant and revisionist foreign policy preferences, as evidenced by Pakistan’s decision to initiate the crisis in the first place. The nuclear balance was highly ambiguous at the time of the war and it is unlikely that either side could have known its opponent’s nuclear capabilities with much certainty. The Kargil War took place in the immediate aftermath of both countries conducting nuclear tests. Assessments at that time acknowledged the difficulty of estimating the India-Pakistan nuclear balance, with continued debate about whether India’s thermonuclear test “fizzled,” how much fissile material both states possessed, and how many weapons both sides had developed.[61] Even Kroenig, who argues that India had nuclear superiority and that this mattered in the crisis, acknowledges that “it is difficult to know the precise nuclear balance of power” in this case.[62] Indeed, the evidence that Kroenig uses to support his claim that the balance of nuclear power mattered for the outcome is that Pakistan ultimately backed down in the crisis, and that Indian officials stated subsequent to the war that Pakistan would be hurt more by a nuclear exchange than India. However, Indian officials would have strong incentives to make such public statements about the effects of a hypothetical nuclear exchange whether or not they were true.[63] Moreover, Pakistan’s behavior in the crisis is also consistent with the conventional balance determining the outcome. Overall, it is hard to make a strong case that nuclear superiority played a key role in determining the outcome of the Kargil War. The key danger of nuclear use was seen by participants on both sides to be Pakistan’s deliberate first use rather than uncontrolled or unauthorized nuclear use. As mentioned above, a key dynamic of the conflict was India ensuring that its forces did not cross the LoC to avoid provoking Pakistan’s deliberate first use of nuclear weapons. Upon granting the Indian army authority to use Indian air force assets at the end of May, the Indian government stipulated that “the air force refrain from crossing the LoC in pursuit of its goals.” India was clear that the Indian army not enlarge “the theater of operations beyond the Kargil sector or…attack Pakistani forces, staging posts, and lines of communications across the LoC, despite the fact that this…entailed the acceptance of heavier casualties.”[64] This restriction remained in place despite substantial Indian casualties and the fact that it would have been tactically useful for India to enlarge the conflict zone to spread out Pakistani forces.[65] This restraint is especially notable given previous Indian responses to Pakistani incursions in both 1965 and 1971, when Indian forces showed little hesitation in invading Pakistan.[66] Both sides in the war were also able to signal their limited intentions, as our framework would anticipate in a staircase crisis. On the Pakistani side, the military took a number of measures to signal limited intentions: Pakistan withheld reserve forces, refrained from the use of air power across the LoC, and did not attempt to cut off the Indian highway in Kargil on the assumption that taking such action “would have far-reaching strategic effects” and risk Indian escalation.[67] Similarly, Pakistan made clear nuclear threats to signal to India that they should avoid broad retaliation. On the Indian side, policymakers deliberately chose not to open a second front of the war or cross the LoC, signaling their limited political goals and lack of interest in a broader war. Overall, therefore, viewing the Kargil War as a staircase crisis accounts for the key dynamics of the case. Cuban Missile Crisis The 1962 Cuban Missile Crisis is widely considered the most dangerous crisis of the Cold War. After detecting the movement of Soviet ships toward Cuba and the development of missile sites, President John F. Kennedy called up 150,000 reservists and issued statements on Sept. 4 and Sept. 13, 1962, warning that the United States “would do whatever must be done” to protect its security.[68] On October 22, Kennedy announced that a naval quarantine would be established around Cuba.[69] Soviet leader Nikita Khrushchev responded by issuing a stern note to Kennedy and instructing Soviet ships headed for Cuba to run the blockade. By October 26, however, Khrushchev’s resolve had waned. Kennedy received a letter from Khrushchev offering to remove the missiles from Cuba in exchange for an end to the blockade and a U.S. assurance that it would not invade Cuba, with a second letter the next day adding a further condition: the removal of U.S. Jupiter missiles from Turkey. Kennedy publicly accepted the terms of the first letter, while in private agreeing to Khrushchev’s demand to remove the Jupiter missiles.[70] On October 28, Khrushchev notified the United States that he had ordered work on the Cuban missile sites to cease and all equipment shipped back to the Soviet Union. The blockade was lifted on November 20, marking the end of the crisis. Coding the Cuban Missile Crisis We argue that the Cuban Missile Crisis was not characterized by incentives for deliberate first nuclear use, despite the United States possessing significant nuclear superiority. In the early 1960s, the United States could have launched 1,000 to 2,000 nuclear warheads at the Soviet Union, the majority of which would have been delivered by over 500 bombers and 200 intercontinental ballistic missiles. The Soviet Union, on the other hand, had only 160 bombers to carry around 260 nuclear warheads, 38 intercontinental ballistic missiles, and 48 nuclear-missile-armed submarines.[71] Despite America’s nuclear superiority, it was not clear that either a disarming first strike or politically meaningful damage limitation was possible. The U.S. government did not know where all of the Soviet warheads were located, and there were concerns that U.S. forces were too inaccurate to successfully target the Soviet arsenal. According to Secretary of Defense Robert McNamara, by 1962 the United States knew that it could not deliver a “splendid first strike,” and that a U.S. first strike “would have led to unacceptably high casualties both in Europe and in the United States” and “destroyed us as well as the Soviets.”[72] McNamara’s recollection is consistent with a briefing that Kennedy received in 1961 from the Chairman of the Joint Chiefs of Staff, which assessed that “under any circumstances—even [in the case of] a pre-emptive attack by the U.S.—it would be expected that some portion of the Soviet long-range nuclear force would strike the United States.”[73] [quote id="4"] Whether such advantages were perceived as politically meaningful within the Cuban Missile Crisis itself is debateable. Certainly, several key U.S. leaders believed that nuclear superiority conferred political advantages to the United States within the crisis.[74] However, this superiority was not absolute, and, crucially, the key leader — Kennedy — was skeptical both that U.S. nuclear superiority granted such benefits and that nuclear first use would offer the United States meaningful damage limitation, stating, “What difference does it make? They’ve got enough to blow us up now anyway.”[75] Similarly, the Soviet Union had little incentive to use nuclear weapons first. A first strike by the Soviets aimed at damage limitation was implausible: A speech delivered by Deputy Secretary of Defense Roswell Gilpatric on Oct. 21, 1961, confirmed that the Soviet Union was behind the United States in the nuclear arms race, and that the United States could endure a Soviet surprise attack and still inflict mass damage on the Soviet Union.[76] U.S. superiority was not, however, sufficient to cast doubt on the Soviets’ own ability to inflict significant destruction on the United States after absorbing a first strike. Moscow was therefore unlikely to face pressures to “use them or lose them” during a crisis. “Missiles are not cucumbers,” Khrushchev quipped, “one cannot eat them and one does not require more than a certain number in order to ward off an attack.”[77] The Cuban Missile Crisis was, however, characterized by low controllability. Indeed, each of our four indicators of this variable suggests low levels of crisis controllability. First, both U.S. and Soviet command and control institutions governing nuclear weapons suffered from significant shortcomings. On the U.S. side, a series of breakdowns of command and communication could have led to accidental nuclear use or other actions that could have triggered escalation. As Scott Sagan concludes, Kennedy “did not…have unchallenged final control over U.S. nuclear weapons.”[78] For example, navigational errors by U.S. pilots led one B-52 to come close to penetrating Soviet airspace and possibly coming within range of Soviet interceptors.[79] Similarly, the U-2 incident at the height of the crisis could easily have led to nuclear escalation: After the American U-2 reconnaissance plane strayed into Soviet airspace, U.S. F-102s armed with nuclear-tipped missiles and possessing the authorization to use them were sent to defend the U-2 from Soviet fighter jets. At that point, the “decision about whether to use a nuclear weapon was in the hands of a pilot.”[80] Beyond these institutional deficiencies, many of the safety features that now exist to prevent accidental explosions had not yet been developed. Benoît Pelopidas notes that in the early 1960s, merely “pull[ing] the arming wires out of a Mark 7 nuclear warhead” would trigger the arming sequence, and that “if the X-Unit charged, a Mark 7 could be detonated by its radar, by its barometric switches, by its timer, or by falling…and landing on a runway.”[81] Moreover, readiness was privileged over safety during the Cuban Missile Crisis. For example, when Strategic Air Command went to DEFCON 2, safety rules had not yet been approved for the B-53 gravity bomb. Strategic Air Command (with the support of the Air Force Chief of Staff) nonetheless requested approval for these non-approved bombs to be loaded onto bombers.[82] Command and control arrangements on the Soviet side also led to the possibility of unauthorized nuclear use. Most notably, Soviet submarines were loaded with nuclear-tipped torpedoes and at least one captain reported that the Cuban Missile Crisis represented his first experience on board a ship carrying nuclear weapons.[83] The authorization to use nuclear weapons appears to have been granted to commanders and included the instructions, “if you get…a hole in your hull… use the nuclear weapons first, and then you will figure out what to do after that.”[84] The Soviets may also have believed that their submarines were less likely to provoke escalation than they really were since the Soviet leadership was unaware that the deployed submarines were the noisier and slower diesel submarines in their fleet that were more likely to be located. Indeed, nuclear launch came close to occurring: The commander of one submarine, which was being targeted with depth charges by U.S. anti-submarine warfare ships, interpreted the explosions of the depth charges as an attack and ordered his officers to ready the submarine’s nuclear torpedoes for use, apparently screaming that “we will die but we will sink them all.”[85] America’s understanding of these risks was limited. The United States was unaware that Soviet submarines were armed with nuclear missiles, and lacked certainty about Soviet command and control more broadly. During a conversation with Secretary of State Dean Rusk, Secretary of Defense Robert McNamara acknowledged not knowing “what kinds of communications the Soviets have with those sites…what kinds of control they have over the warheads.”[86] Second, the U.S. and Soviet red lines for nuclear escalation were unclear to both sides at the outset of the crisis. The Soviet Union misjudged America’s red lines by placing missiles in Cuba in the first place. Khrushchev initially believed that once the missiles were installed in Cuba the United States would be unwilling to risk war to remove them.[87] This belief was overturned, however, as Khrushchev became deeply concerned by U.S. mobilizations and nuclear alerts, writing to Kennedy on October 26 of the tightening “knot of war” and the difficulty of de-escalating hostilities.[88] Khrushchev’s concern increased further on October 27 with news that a Soviet commander in Cuba had shot down an American U-2 plane without his authorization, and that Cuban leader Fidel Castro was advocating a nuclear strike against the United States.[89] Similarly, the United States was unsure what military actions might trigger Soviet escalations: U.S. officials were divided over the significance the Soviets attached to missiles in Cuba, and what the Soviets might be willing to risk to avoid removing them. Similarly, U.S. officials assumed that the Soviet Union would respond if the United States attacked Cuba but were unsure what form those reprisals would take and whether they might lead to general war or a more limited Soviet response. Indeed, officials in the Executive Committee of the National Security Council made a range of arguments regarding the relative likelihood of different Soviet responses should the United States invade Cuba[90] Third, conventional and nuclear forces interacted during the crisis on multiple occasions in ways that reduced the controllability of the crisis and raised the risk of nuclear use. As discussed above, Soviet submarines could have launched nuclear weapons while under pressure from conventional U.S. anti-submarine warfare assets unaware that they were engaging nuclear-armed Soviet submarines. On the U.S. side, the F-102s sent to retrieve and escort the U-2 inadvertently flying into Soviet airspace could have launched their own nuclear weapons while under pressure from Soviet fighters. This interaction between nuclear and conventional forces raised the risk of inadvertent escalation and reduced the controllability of the crisis. Fourth, crisis communication between the United States and Soviet Union was widely recognized to be problematic, leading to the establishment of the U.S.-Soviet “hotline” in 1963. Official messages took six hours to deliver, while unofficial channels were prone to miscommunication. The confusion that resulted from contrasting letters sent by Khrushchev on October 26 and 27 exemplifies the problematic nature of crisis communication. Kennedy received a letter offering to remove the missiles from Cuba and to cease further shipments in exchange for ending the quarantine and a non-invasion pledge. This message took twelve hours to receive and decode. By the time a reply had been drafted, a second letter had arrived in which Khrushchev added a further condition: the removal of Jupiter missiles in Turkey. Puzzled by the shifting demands, Kennedy publicly accepted the terms of the first letter, while privately agreeing to remove the Jupiter missiles.[91] Predictions The Cuban Missile Crisis exhibited few incentives to use nuclear weapons first and low levels of crisis controllability. It is therefore best understood as a “brinkmanship” crisis. What dynamics should we therefore expect to see in this case? First, we should expect the crisis to have been primarily characterized by the manipulation of risk, with the conventional or nuclear balance affecting the crisis outcome in less direct ways. Second, the primary danger of nuclear use should be expected to have come from uncontrolled nuclear escalation rather than deliberate first nuclear use. Third, signaling should have been feasible within the crisis.[92] These predictions are, indeed, confirmed. First, scholars have often been skeptical that U.S. nuclear or conventional military superiority in the region affected the outcome in a direct way, and if it did affect the outcome, that it did so by affecting U.S. resolve and willingness to manipulate risk.[93] There is indeed evidence that some of Kennedy’s advisors believed that U.S. nuclear superiority should factor into their calculations.[94] However, as discussed above, Kennedy himself seems to have been disinclined to draw comfort (or courage) from U.S. nuclear advantages. Historians have largely shared this assessment: Marc Trachtenberg concludes that “there is no evidence that President Kennedy and his advisers counted missiles, bombers, and warheads, and decided on that basis to take a tough line,” while James Cameron shows that, despite Kennedy having come to power railing against the (fictional) missile gap with the Soviet Union, once in office, he viewed U.S. nuclear superiority as largely useless.[95] As veterans of the crisis McNamara, Rusk, McGeorge Bundy, Ted Sorensen, Roswell Gilpatric, and George Ball later commented, “American nuclear superiority was not in our view a critical factor…Not one of us ever reviewed the nuclear balance for comfort in those hard weeks. The Cuban missile crisis illustrates…the insignificance of nuclear superiority.”[96] Although the United States succeeded in achieving its goals once the crisis had begun, and is therefore often (and reasonably) understood to have “won” the crisis,[97] the actual result of the crisis — a quid pro quo that left the Soviets better off than the pre-crisis status quo[98] — seems inconsistent with both American strategic nuclear superiority as well as U.S. conventional superiority in the region. Instead, as Schelling argues, the crisis is best understood as a case of states manipulating risk: “The Cuban Crisis was a contest in risk taking, involving steps that would have made no sense if they led predictably and ineluctably to a major war, yet would also have made no sense if they were completely without danger.”[99] Our argument does not require nuclear superiority to have had no effect during the crisis. For example, as discussed above, nuclear superiority could affect risk tolerance or resolve within the framework of brinkmanship crises. Nonetheless, the brinkmanship model accurately captures the key dynamic — the manipulation of risk — of the Cuban Missile Crisis. [quote id="5"] Second, historians, political scientists, and participants in the crisis agree that the primary danger of the Cuban Missile Crisis was uncontrolled escalation rather than deliberate first nuclear use. As a group of former officials from the Executive Committee of the National Security Council later recalled, “The gravest risk in this crisis was not that either head of government desired to initiate a major escalation but that events would produce actions, reactions, or miscalculations carrying the conflict beyond the control of one or the other or both.”[100] Similarly, scholars have repeatedly emphasized the importance of luck in preventing nuclear war during the Cuban Missile Crisis. For example, Sagan writes that “good luck [was] involved in avoiding accidental war in October 1962”, while Dean Acheson concluded that the peaceful resolution of the crisis came down to “dumb luck.”[101] Len Scott and Steve Smith write that “the fact that the crisis did not lead to nuclear war was due…to good luck,” while Pelopidas concludes that the “peaceful outcome cannot be reduced to successful, fully informed crisis-management.”[102] The brinkmanship model, by emphasizing the dangers of uncontrolled escalation, sheds light on why luck was required to peacefully negotiate the Cuban Missile Crisis. Third, as anticipated, both sides engaged in signaling and escalation using conventional military forces and the alerting of nuclear forces, behaviors that the brinkmanship model would anticipate. American officials “were willing during the crisis to accept a certain risk of nuclear war; and…the risk of nuclear war was consciously manipulated.”[103] Military deployments and alerts were ordered less because of their narrow military utility but more as measures to signal U.S. intentions and raise the risk of war. For example, McNamara argued that the point of the blockade “was not to shoot Russians but to communicate a political message from President Kennedy to Premier Khrushchev.”[104] Throughout the crisis, the United States used escalatory measures as signaling mechanisms: When Kennedy addressed the nation on October 22, for example, U.S. nuclear forces were placed on DEFCON 3 alert, Polaris submarines moved out of their ports to pre-assigned stations, and U.S. military commands throughout the world increased levels of readiness for war.[105] On October 24, Kennedy made the unprecedented decision to raise the nuclear threat level to DEFCON 2 — one level short of general war.[106] On October 27, Minuteman solid fuel missiles were placed on alert at Malmstrom Air Force Base in Montana.[107] As Gen. David Burchinal, the director of plans on the Air Staff, recalled in an oral history, “All these moves were signals the Soviets could see and we knew they could see them.”[108] Overall, viewing the Cuban Missile Crisis as a brinkmanship crisis accurately captures key dynamics of the case.

Contemporary and Future Crises: Doklam and U.S.-North Korea

Our framework therefore sheds light on prominent historical crises. Accounting for the heterogeneity of nuclear crises allows us to understand key differences between the Cuban Missile Crisis and the Kargil War better than a single model of nuclear crisis. What, then, does the framework offered here suggest about more contemporary crises? In this section, we briefly use our framework to shed light on the 2017 Doklam crisis between India and China and a potential U.S.-North Korean crisis. The Doklam Crisis The 2017 Doklam crisis between India and China — a standoff over disputed territory where the borders between China, India, and Bhutan intersect — would be classified as a stability-instability crisis according to our framework.[109] First, neither side had strong incentives for first nuclear use: Both India and China had relatively small nuclear arsenals, geographically large territories and dispersed populations, longstanding no-first-use policies, and nuclear postures that are designed to credibly threaten retaliation in the aftermath of a nuclear attack rather than first use.[110] Second, the crisis was characterized by high levels of controllability: Neither sides’ nuclear weapons were close to the conflict zone, both countries’ nuclear postures made unauthorized or accidental nuclear use unlikely, high levels of communication between the two sides existed throughout the crisis, and each country’s declaratory no-first-use policy made it highly unlikely that either side would accidentally stumble over the other’s red lines for nuclear use.[111] Indeed, viewing the crisis as a stability-instability crisis appears to correctly account for key dynamics of this case. Despite the relatively high levels of military escalation — hundreds of troops were deployed to the region — there was little fear by either side that nuclear weapons would be used. Signaling took place using conventional troop deployments but without using nuclear threats. The outcome of the crisis — a return to the status quo desired by India and Bhutan — appears consistent with the conventional balance given India’s “unique hard power advantages in the Himalayan region.”[112] Finally, viewing the Doklam standoff as a stability-instability crisis provides an explanation for why China was prepared to provoke a crisis with another nuclear-armed state over relatively low stakes: Stability-instability crises are relatively “safe” in terms of the risk of nuclear escalation, and states should therefore be willing to provoke them to secure even relatively limited interests. A Possible U.S.-North Korean Crisis Finally, what does our framework suggest about a potential U.S.-North Korea crisis? Both sides in a potential U.S.-North Korea nuclear crisis might be incentivized to use nuclear weapons first.[113] This is both because North Korea appears to be adopting an asymmetric escalation posture and because of the significant disparities between the nuclear capabilities of the two sides, which means that North Korea plausibly lacks a secure second-strike capability. For North Korea, using nuclear weapons early in a conventional conflict might be the only way to prevent a conventional defeat by a far more powerful enemy or to make the United States think twice about pursuing regime change.[114] As Vipin Narang argues, North Korea’s nuclear strategy appears to be one of asymmetric escalation: threatening nuclear first use to degrade a conventional invasion while retaining longer-range nuclear missiles to deter nuclear retaliation by the United States. Narang notes that,

faced with the prospect of a U.S.-led invasion, Pyongyang’s conventional inferiority requires it to degrade the United States’ ability to sustain the attack against it. This means it essentially has no option but to use nuclear weapons first against targets such as Andersen Air Force Base in Guam, which stations American bombers, and a variety of allied bases in Japan and South Korea. North Korea has to use nuclear weapons there because it does not have enough conventional warheads to damage the bases meaningfully; a conventional response would not slow or stop a U.S. onslaught.[115]

The United States may also face temptations for first nuclear use.[116] A nuclear counterforce strike might be crucial to removing North Korea’s ability to retaliate against South Korea or Japan (or the United States): The imperative to destroy North Korean offensive capabilities could thus lead to the temptation to use nuclear weapons first and early in a conflict. As David Barno and Nora Bensahel argue, only a “surprise nuclear strike provides a decisive option. There is simply no other way to destroy North Korea’s nuclear capabilities while minimizing the risk of massive conventional or nuclear retaliation.”[117] Barry Posen, in arguing against a U.S. war with North Korea, acknowledges that “a surprise American nuclear attack would offer the greatest chance of eliminating the North Korean nuclear arsenal and of preventing a conventional counterattack,” making it a potentially attractive option if war was deemed inevitable or necessary by U.S. planners.[118] Moreover, recent scholarship has suggested that some impediments to U.S. nuclear use may be weaker than anticipated. For example, the U.S. public may, in fact, be willing to endorse nuclear use under a wide range of scenarios.[119] Similarly, Daryl Press and Kier Lieber argue that a nuclear counterforce attack against North Korea could potentially be conducted with minimal casualties and limited environmental consequences.[120] In short, both sides in a potential U.S.-North Korean crisis could plausibly perceive incentives for first nuclear use. Furthermore, a crisis between the United States and North Korea would likely have low levels of controllability:[121] The robustness of North Korea’s command and control systems is unknown and would likely be aggressively targeted in the initial stages of any military confrontation; there are few institutionalized avenues for crisis negotiation or communication between the two sides; North Korea’s or America’s red lines for nuclear use are unclear and ambiguous; and while any nuclear use would likely be limited on the U.S. side given the small geographic territory of North Korea, North Korea’s small arsenal makes it more likely that it would have to quickly use all weapons at its disposal in order to try to respond to any U.S. first strike.[122] If our assessment of incentives for first use and controllability are correct, a potential crisis between the two countries would likely unfold according to the logic of the firestorm model — the most volatile and dangerous of the four models and one in which sudden and significant escalation across the nuclear threshold is possible. U.S. policymakers should therefore be under no illusions that a conventional war with North Korea will reliably remain conventional — rapid nuclear escalation is highly possible. Given the costs of such a war, avoiding any crisis with North Korea that could quickly escalate should be a higher priority for U.S. policymakers than if a potential U.S.-North Korean crisis were likely to unfold according to one of the other models of nuclear crisis.

Conclusion

I. The Wrong Revolution?

How should nuclear weapons affect U.S. strategy and statecraft? What does the leading theory — the nuclear-revolution school — say about how American grand strategy should be influenced by the bomb? Under the nuclear-revolution framework, assessing the purpose and consequences of the bomb through a grand-strategic lens can make for an awkward fit. After all, grand strategy is about making choices: what means and instruments, including war, states and their leaders select to achieve desired ends in geopolitical competition in international relations. It reflects “a purposeful and coherent set of ideas about what a nation seeks to accomplish in the world, and how it should go about doing so.”[2] Grand strategies vary enormously over time, location, individuals, and regimes. The United States has pursued a variety of grand strategies since its founding, and debate is fierce over what grand strategy it should pursue today and what means it should employ. The nuclear-revolution school argues that the bomb severely constrains and limits — and at times eliminates — the grand-strategic choices that were available to states and statesmen in the past. Robert Jervis, the leading thinker in the nuclear-revolution school, has argued that “[f]orce and the threat of it cannot support foreign policy in the same way that it did in the past.”[3] Historian Lawrence Freedman agrees, suggesting that the notion of a nuclear strategy “is a contradiction in terms.”[4] What is the “nuclear revolution” framework, and what predictions and explanations does it offer? While scholars differ on some aspects,[5] Stephen Walt has nicely defined its broad outlines:

As refined by scholars like [Bernard] Brodie, Thomas Schelling, Glenn Snyder, Robert Jervis, Kenneth Waltz, and Stephen Van Evera, nuclear weapons are said to provide states with the ability to protect their sovereignty and independence not via direct defense but rather through deterrence.

According to the “logic of the ‘nuclear revolution,’ therefore, states with second-strike capabilities were secure against attack and didn’t need to worry very much about their sovereignty or independence.” The nuclear revolution “means that ‘nuclear superiority’ was a meaningless concept. … A handful of survivable weapons makes it very unlikely that another state will attack you directly or try to invade and take over your country.”[6] According to Jervis, the leading scholar in this tradition, nuclear weapons “can kill but not influence.”[7] Nuclear weapons even “eliminate the security dilemma,” the phenomena that many scholars believe drove international conflict for centuries, making cooperation among states more likely.[8] Nor can they be used for much else besides deterrence. As Todd Sechser and Matthew Fuhrmann argue in a recent study, “For all the money spent on atomic bombs, they have bought precious little coercive leverage for states.”[9] [quote id="1"] The nuclear revolution should have had important consequences for proliferation dynamics, nonproliferation policies, and alliances. Joshua Rovner explains that according to the nuclear-revolution view, “if nuclear weapons were great for deterrence but lousy for battle, then Washington should have been sanguine as new countries went nuclear. It might even have been optimistic, since proliferation would, under this theory, lead countries to become cautious.”[10] Even if the United States wanted to stem the spread of nuclear weapons, however, the effort would be futile. According to Kenneth Waltz, “[I]f countries feel insecure and believe that nuclear weapons would make them more secure, America’s policy of opposing the spread of nuclear weapons will not prevail.”[11] Waltz, the most influential international relations theorist of modern times and one of the more extreme advocates of the nuclear-revolution framework, went further still, arguing that nuclear weapons “make alliances obsolete.”[12] The mere presence of the bomb would override the grand-strategic choices made by a particular state or leader. “Nuclear weapons can carry out their deterrent task no matter what other countries do.”[13] The key insight of this framework is that the bomb is a defensive weapon of such powerful force that it transforms strategy and statecraft, constraining the grand-strategic options available to states and leaders before the nuclear age, regardless of a state’s history, geography, culture, or regime type. According to Waltz, “American estimates of what is required for deterrence were absurdly high.” In other words, “not much is required to deter.”[14] Summing up the conventional wisdom among scholars in this tradition, Charles Glaser and Chaim Kauffman argue that the nuclear revolution reveals that “this technology so heavily favors defense that when all the major powers have nuclear weapons variation in other factors becomes relatively unimportant.”[15] According to Stephen Van Evera, “the nuclear revolution gave defenders a large military advantage,” so large that conquest “became virtually impossible.”[16] John Mearsheimer similarly concludes that “there is no question ... the presence of nuclear weapons makes states more cautious about using military force of any kind against each other.”[17] How well did the theory of the nuclear revolution do in predicting American nuclear weapons policy and explaining the role of the bomb in U.S. grand strategy? The framework’s key point — that nuclear weapons made total, thermonuclear war a horrifying absurdity to be avoided at all costs — is of course a profound insight. As the historian John Lewis Gaddis argued during the Cold War, “It seems inescapable that what has really made a difference in inducing this unaccustomed caution has been the workings of the nuclear deterrent.”[18] Yet, the implications of this incontrovertible truth for American grand strategy are both contested and uncertain. Did the United States accept mutual vulnerability with nuclear-armed adversaries, as the theory would have predicted? Was the bomb understood only as a defensive weapon to defend American sovereignty and territorial integrity? Were American leaders nonplussed as other states expressed interest in the bomb, and, even if concerned, did they recognize and accept that there was little they could do to stop proliferation? Did alliances become less important, and was the United States less likely to use force of any kind? Perhaps most critical, did the United States behave like any other state in the system, bowing before the constraints the nuclear revolution imposed on its strategy and statecraft? Taken to its logical end, this school of thought suggests that many states should seek nuclear weapons and that the United States should or could do little to stop other states from pursuing and attaining their own bomb. When building arsenals, the ease of securing a second-strike capability meant that seeking quantitative or qualitative advantages beyond a certain point would be a foolish goal for a state: At best it would be wastefully expensive; at worst, destabilizing and dangerous. According to the theory, strategic stability, both in dyadic competitions and on a broader, horizontal scale, should emerge naturally from the nuclear revolution.[19] Nor should the particular circumstance, history, leadership or regime type, or interests of the nuclearizing state affect the powerful, system-wide effects of these weapons. Or so went the story largely crafted by American academics specializing in security and strategic studies.[20] As Rovner has noted,

If the nuclear revolution affected grand strategy, the United States should have settled for a small arsenal for the sole purpose of deterrence. It would never have sought to integrate nuclear and conventional forces, because nuclear weapons were fundamentally different in that they could never be used. U.S. leaders should have recognized that defenses against nuclear attack were futile, and avoided pouring time and money into such efforts. And they should have managed the process of proliferation so that states, great and regional powers alike, enjoyed the security benefit of a reliable second-strike capability. None of these things happened.[21]

Why not? Exceptional, but Not for the Reasons Many Think The nuclear-revolution framework provides a powerful lens to understand two of the most important aspects of world politics since 1945: the disappearance of great-power war and the non-use of nuclear weapons against adversaries after the United States dropped atomic bombs on Hiroshima and Nagasaki, Japan, in August 1945. It is less helpful in explaining other aspects of U.S. grand strategy in the nuclear age. U.S. behavior and policies diverged from expectations of the nuclear-revolution school in at least three ways. The first involves American leaders’ interest in making nuclear weapons such a core element in U.S. grand strategy. According to the nuclear-revolution school, the most powerful role of nuclear weapons is as “invasion insurance,” or to prevent the conquest of sovereign territory. Whatever the fears raised by the Japanese attack of Pearl Harbor, the United States has faced almost no threat of conquest since the Civil War ended in 1865. A United States without nuclear weapons — in 2019 or in 1955 or 1975 or any other year — faced almost zero threat of conquest. Rarely has a state had less need for the bomb to guarantee its immediate territorial integrity, sovereignty, and security.[22] Yet, no state has invested greater resources in developing and deploying nuclear weapons, nor has any other state relied more heavily on nuclear weapons to implement its grand strategy. The United States has spent astronomical sums on nuclear weapons since 1940, dwarfing the expenditures of other rivals.[23] It plans to spend an additional $1.3 trillion over the next few decades.[24] This is not to suggest that it is surprising the United States pursued and developed the bomb, or even that it pursued a survivable nuclear capability. What is surprising, however, is the central and expensive role that nuclear weapons have played in American grand strategy. Advocates of strategic stability and the nuclear-revolution framework, to say nothing of the historians of American grand strategy before 1950, would likely struggle to explain the United States’ experiments with “nuclear sharing” with its allies, its willingness to use nuclear weapons first in a conflict, and pre-delegating authority to launch the bomb to military commanders in the field.[25] Second, extraordinary new scholarship is making it increasingly clear that the United States never permanently abandoned its efforts to achieve nuclear superiority.[26] For a decade and a half after the United States lost its nuclear monopoly, it strove diligently to build far more deliverable nuclear weapons than any other country.[27] It is true that the United States began to accept quantitative equality with its primary adversary, the Soviet Union, by the late 1960s and 1970s. Two points are in order. First, the United States accepted parity only reluctantly. As James Cameron astutely observed, “Nixon hated MAD, believed its logic was defeatist and naïve, yet he signed agreements that enshrined it at the heart of the United States’ relations with the Soviet Union.”[28] Mired in a disastrous war in Southeast Asia and facing both economic and domestic political constraints on military spending, the United States pulled in its horns. Second, while American policymakers accepted quantitative parity, they still sought qualitative primacy over U.S. adversaries. How did the United States seek this superiority? Concurrent to American policymakers negotiating and accepting the Strategic Arms Limitation Talks (SALT I and SALT II) and the Anti-Ballistic Missile treaties, the U.S. government undertook a massive, extraordinary effort to develop and deploy more sophisticated nuclear weapons and systems to support them. This allowed the United States to exploit its natural advantages over the Soviet Union. As John Mauer has argued,

American leaders raced the Soviets in military technologies where the United States was perceived to enjoy significant advantages, while simultaneously entangling the Soviet Union in an arms control regime that would limit areas of Soviet strength. By combining arms racing and arms control, the United States pursued a holistic offset strategy.[29]

As historians Niccolo Petrelli and Giordana Pulcini reveal, between 1969 and 1976 the Nixon and Ford administrations “actively sought to transcend nuclear parity.”[30] In the years after quantitative parity was accepted, the United States developed and deployed a number of technologically sophisticated and expensive capabilities, including the Pershing II, MX, Trident D-5, as well as cruise missiles. It also invested enormous resources into missile defense; anti-submarine warfare (i.e., targeting and eluding Soviet nuclear submarines); and command, control, communications, and intelligence capabilities.[31] As Austin Long and Brendan Green demonstrate in their path-breaking work, the United States “invested massive resources into intelligence capabilities for a first strike, including successful innovation in tracking submarines and mobile missiles.”[32] These expenditures were oriented toward systems whose characteristics and capabilities, such as speed, stealth, intelligence, and accuracy, were best suited to a nuclear posture that focused on counterforce, damage limitation, and even preemptive uses. In other words, the nuclear forces built in the decades after the SALT and ABM treaties made little sense if the United States had fully embraced the consequences of mutual vulnerability spelled out by the nuclear-revolution school. This is certainly how the Soviet Union perceived these efforts. Because of the “development of American counterforce capabilities,” Soviet leaders “were uncertain they could indefinitely maintain a secure second strike in spite of their strenuous efforts.”[33] [quote id="2"] This interest in maintaining superior nuclear capabilities continued after the Cold War ended.[34] As a 2003 RAND report observed,

The force is larger than it needs to be if deterrence by threat of nuclear retaliation is the sole objective of U.S. nuclear strategy. Even a mildly expanded target base that included selected targets in emerging nuclear powers as well as chemical and biological weapons facilities in a larger set of countries would not necessarily require the sort of force that the United States plans to maintain. What the planned force appears best suited to provide beyond the needs of traditional deterrence is a preemptive counterforce capability against Russia and China. Otherwise, the numbers and the operating procedures simply do not add up.[35]

It has been argued that bureaucratic and organizational politics were the primary drivers of these expensive, risky, and politically polarizing nuclear postures.[36] Organizational and bureaucratic factors no doubt played some role, but the fact that the search for qualitative superiority has spanned decades, encompassing multiple administrations and great shifts in global politics, undermines such interpretations. As Green and Long argue, “In sum, it was international politics, not domestic politics, which killed hopes for nuclear stability.”[37] Why did the United States seek nuclear primacy? This relates to the third point: The United States asked more of its nuclear weapons in its grand strategy than any other nuclear state.[38] Most states seek nuclear weapons to protect themselves from invasion and conquest. This is a scenario the United States has not had to worry about, and even if it did, such protection would not require the massive, sophisticated nuclear forces and related systems the U.S. government built. Instead, the United States employed its nuclear forces to achieve far more ambitious, historically unprecedented goals. From the early 1950s onward, the United States pursued an audacious strategy of relying on its massive nuclear capabilities to both protect far-flung allies from nuclear attack or conventional invasion while also inhibiting the nuclear desires of those same allies. As Green and Long demonstrate, “Successive administrations discovered that the threat of retaliation and the existential risk of nuclear escalation posed by stability doctrines were not a sufficient military solution for their perceived geopolitical challenges.”[39] There has long been a tension between the goal of strategic stability and extending deterrence to America’s allies. As analysts from RAND pointed out in 1989, there was a clash between the “objectives of enhancing first[-]strike stability, on the one hand, and extending deterrence and limiting damage, on the other,” such that the more robust the Soviets believed stability was “the less they might hesitate to precipitate a deep crisis by engaging in serious aggression.”[40] As Earl Ravenal explained in 1982, extending deterrence demanded expensive and potentially destabilizing counterforce capabilities, employed in first-strike strategies. “Such a damage[-]limiting attack, to have its intended effect, must be preemptive.”[41] Permanently extending deterrence while inhibiting proliferation have been cornerstones of American grand strategy for so long it is easy to forget how historically unusual, difficult, and demanding this ambition is. There was, of course, great tension between the goal of a preemptive strategy and strategic stability. Counterforce strategies were not about mutual vulnerability, Ravenal makes clear:

[C]ounterforce and first nuclear strike are mutually dependent. A first strike implies counterforce targeting, since the only initial attack that makes sense is a damage-limiting strike, the destruction of as much of the enemy’s nuclear force as possible. And counterforce targeting, in return, implies a first strike, a preemptive attack, because a second strike against the enemy’s missiles is useless to the extent that one’s missiles would hit empty holes.

As an assistant to Defense Secretary Robert McNamara told a reporter in the mid-1960s, “There could be no such thing as primary retaliation against military targets after an enemy attack. If you’re going to shoot at missiles, you’re talking about first strike.”[42] To be clear, this is not to argue that American leaders seriously contemplated a first strike or even made full-out efforts to acquire meaningful first-strike forces.[43] While American presidents refused to accept qualitative parity with the Soviet Union and pursued expensive and arguably dangerous counterforce options, they also shied away from seeking a full-scale, first-strike capability. One of the great unanswered questions of the nuclear age involves what U.S. leaders thought they were getting with this qualified superiority.[44] Strategies of inhibition required strategic forces that went far beyond mutual vulnerability, but such postures might dangerously undermine strategic stability.[45] One promising explanation is Glenn Kent and David Thaler’s idea of “optimum instability” — developing enough counterforce to make the other side think you might go first in a crisis but without making your adversary think you are eager to do so. “Indeed, one might argue that an optimal amount of first-strike instability is possible: that is, enough to deter the Soviets from generating a major crisis (say, by invading Western Europe), but not enough to allow a major crisis to spiral out of control.”[46] This aggressive posture was pursued, in large measure, to inhibit the development of independent nuclear weapons programs among ostensible allies. The United States went to great lengths to prevent what otherwise might have been a natural development in world politics: the emergence of independent, capable states acquiring their own nuclear weapons. Nuclear weapons would, after all, effectively guarantee their possessors against invasion and conquest for the first time — ever. Rare was the state in history that turned away from an effective military technology or turned over its security to another state. Washington, however, aggressively pursued a wide range of policies to achieve inhibition, including threats of force or abandonment, forward deployed forces, enacting sanctions, selling arms, and encouraging treaties and norms.[47] To achieve its goals of inhibition, the United States often cooperated with its most bitter ideological and geopolitical adversary, the Soviet Union, at the expense of U.S. partners and allies.[48] It is easy to lose sight of how strange, even radical, these grand-strategic choices were when they were developed in the 1950s and the extent to which they remain so today. There is little in the nuclear-revolution theory that can explain the cost, number, and technological sophistication of America’s nuclear weapons systems, nor the aggressive postures in which they were employed. Imagine explaining in the early 20th century that the United States was going to risk a global war that would kill tens of millions of people to defend a conventionally indefensible portion of a city — West Berlin — 100 miles within enemy territory that had no geostrategic value whatsoever. Imagine that everyone would think this was normal (and call it “extended deterrence”). Imagine the weapons and military strategy necessary to convince an adversary that was far closer, that had superior conventional arms, and that, arguably, had more at stake that this was a credible commitment. Try to imagine a parallel in world history for this situation before 1950. Then think about how the strategists who constructed these theories did so based largely on their view of how this story unfolded between 1958 and 1963. The United States, which had little need for nuclear weapons to prevent an invasion or nuclear attack upon its homeland, built, at great expense, the largest and most sophisticated nuclear forces in the world and placed them within forward-leading and often preemptive strategies, backed by military technologies that potentially undermined strategic stability. American leaders worked feverishly, often with adversaries, to prevent the rise of independent nuclear-weapons states — ally, enemy, or neutral — and this remains a cornerstone of U.S. grand strategy. These strategies were exceptional. In one sense, however, nuclear weapons did revolutionize American grand strategy. Before 1949, the United States had no permanent peacetime alliances. America demobilized during peacetime, and it typically pursued slow strategies of attrition when conflict did arise. Congress was widely perceived as the more powerful foreign policy actor during peacetime, while military leaders were afforded little leeway. All of that changed dramatically after the early 1950s, across administrations and shifts in the structure of the international system.[49] Since then, the United States has developed strategies, on semi-permanent alert status, that escalate quickly — even preemptively — with nuclear weapons, and it has concentrated enormous power to initiate war into the hands of the American presidency, all on behalf of defending a sprawling set of countries around the world. Simply put: There was a (thermo-) nuclear revolution that shaped American grand strategy — but it was a much different revolution than the conventional wisdom puts forward.

II. Missing Histories

What is the history of U.S. nuclear weapons and their role in American grand strategy? Careful assessment of what is known — and whether these accounts accurately capture the past — is critical. Most theories and policy analysis are based on assumptions and beliefs about what happened in the past. Unfortunately, less is known about U.S. nuclear history and its role in American grand strategy than is presumed, and what many people do know is often overly simplistic, misleading, or otherwise problematic. Why is this the case? The major works that cover the history of U.S. nuclear weapons policy were, for the most part, written some time ago — before many primary documents were released. These works were often penned not by historians but by policy participants, scholars of strategic and security studies, or analysts outside of the academy. Many of these works are excellent first cuts at history.[50] Most, however, are older, do not engage recent archival finds, and often accept the logic of the nuclear-revolution school to explain U.S. policy. [quote id="3"] What of the discipline of academic history? To be sure, impressive international research has been conducted into various elements of global nuclear history, especially the issues surrounding various state decisions about whether to build a bomb.[51] There are also excellent monographs exploring particular aspects of U.S. nuclear history.[52] Writ large, however, treatment of American nuclear weapons history has been episodic rather than systematic. This is part of a larger, and unfortunate, decades-old trend within history departments. As Hal Brands has argued, “The historical profession in the United States has simply deprioritized the study of statecraft and international relations, at least as those subjects were conventionally understood.”[53] This is especially true in nuclear history, where there is almost no participation by scholarly historians on these contested issues. The academic discipline of history

has largely abandoned studying important issues such as international security and nuclear weapons and is in the midst of a four-decade, slow[-]motion act of collective suicide. There simply is not, nor will there be anytime soon, a critical mass of diplomatic and military historians available to research these important questions or make use of these amazing materials.[54]

Even when scholarly historians do focus on issues of foreign policy or international relations, nuclear questions often get short shrift. Large, synthetic accounts of the Cold War either accept the nuclear-revolution framework or do not break new ground on nuclear issues.[55] Arguably far more is known about the development of U.S. human rights policies, for example, or the role of race and gender in American foreign policy, than about how U.S. decision-makers have discussed and debated the purpose and consequences of the bomb in its relations with the world. Given the extraordinary importance and potential consequences of American nuclear weapons policies, and the massive increases in primary documents available to researchers, the failure of the American historical profession to support and undertake this work is shameful. The Challenge of Nuclear History What would a comprehensive history of U.S. nuclear weapons policy and its role in grand strategy look like? To be fair, undertaking historical work on nuclear issues is particularly difficult. There are the methodological challenges that will be laid out in the next section: assessing historical evidence and making causal claims is difficult when the issues at stake — deterrence, assurance, credibility, and resolve — are unobservable. Speeches and written evidence are often hard to interpret. Top-secret deliberations often reveal American presidents taking contradictory approaches or blowing off steam. U.S. officials’ public pronouncements are frequently intended to convey signals to various audiences and may not represent operational policy. Furthermore, the decisions behind nuclear policies and strategies are some of the government’s most carefully guarded activities, and access to top-secret documents is heavily restricted. While the situation has improved considerably in recent years, archival materials on nuclear policy are notoriously difficult to declassify, and even when they are released, they are often heavily redacted. With important pieces of evidence unavailable, constructing an all-inclusive, seamless narrative remains enormously challenging. A larger question looms: What does it mean to talk about nuclear history? The history of nuclear weapons was once told as the history of the Cold War, and vice-versa. It is now understood that they were not the same. Sometimes nuclear history and Cold War history overlapped, while at other times they moved on independent paths, so much so that it is often hard to determine whether nuclear weapons prevented the bipolar competition from breaking out into war or dangerously exacerbated underlying tensions. A history that conflates Cold War and nuclear dynamics could not, for example, fully explain why the United States cooperated with the Soviet Union to deny their respective allies nuclear weapons.[56] Alliances once ascribed solely to Cold War dynamics, in Europe, the Middle East, and Asia, have not only persisted since that struggle ended but have broadened and deepened in ways that show that nuclear considerations (among other non-Cold War factors) were always at their root. It is essential to disentangle the interconnected but distinct histories of the nuclear age and the geopolitical and ideological rivalry between the superpowers.[57] The Cold War was not, however, the only powerful historical force interacting with, shaping, and being shaped by nuclear history. Decolonization, whose deep roots in imperialism and resistance date back centuries, had an enormous influence — in many cases, more than the Cold War — shaping nuclear decision-making in Great Britain, France, Israel, South Africa, India, and Pakistan, as well as others that decided not to acquire the bomb. Other factors, such as regional dynamics and the effects of globalization, influenced America's grand strategy and approach to nuclear weapons. Disentangling competing global histories since the end of World War II is a difficult but necessary task when trying to understand how nuclear weapons influence international relations. There is also the question of periodization and chronology. Is the nuclear age one continuous stream, beginning in August 1945 — if not earlier — and continuing to the present? Or are there sharp breaks dictated by key technological advances such as the development of thermonuclear weapons or intercontinental ballistic missiles? Important political events had profound consequences for nuclear history: the emergence of Soviet nuclear parity and the negotiation of major arms-control treaties, the end of the Cold War, and the collapse of the Soviet Union. Is there such a thing as a second nuclear age, and, if so, how is it different from the first? Defining nuclear history and its scope is difficult; calculating how American grand strategy incorporates and reacts to these shifts even more so. Competing Histories The most important historical challenge is reconciling contending and often contradictory narratives that chronicle the past. This is especially true when trying to understand the American experience with the bomb. There are at least four competing histories of how nuclear weapons influenced U.S. grand strategy and vice-versa: intellectual, rhetorical, operational, and presidential. Assessing which of these strands is most important, and how they interact with each other, is challenging. The first strand is the intellectual history of the United States. For many within the security studies community, the most familiar strand is what might be called the “Wizards of Armageddon” story. In this tale, smart strategists, typically civilians from universities and think tanks like the RAND Corp., wrestled with and explained to the wider world the new realities created by nuclear weapons. In the process, great thinkers such as Bernard Brodie, Thomas Schelling, Albert Wohlstetter, and others made sense of “the unthinkable,” created modern deterrence theory, transformed U.S. policy and grand strategy, and probably prevented World War III. This history is both familiar and comforting — to the extent that nuclear history can be comforting — because it explains the rise of the field of security studies and provides the intellectual architecture for the ideas behind nuclear peace. Because a key part of the stylized telling is how the wizards transformed American policy (and saved the world!), it also suggests that scholarly ideas matter to policymakers. As Marc Trachtenberg points out, however, analysis of the civilian nuclear strategists often suffered from being both “apolitical in substance” and “ahistorical in method.”[58] Bruce Kuklick is even more harsh: The strategists “professed deep understanding” but actually “groped in the dark” and their ideas “had little causal impact.”[59] The problem is that as history, the story of the “Wizards of Armageddon” is, at best, overstated and misleading; at worst, it bears little relation to what actually happened.[60] The second history is rhetorical. Through speeches and published documents, the United States government has used public declarations to indicate its views on nuclear weapons. Prominent examples include Eisenhower administration Secretary of State John Foster Dulles’s “massive retaliation” speech given at the Council on Foreign Relations in 1954, Defense Secretary Robert McNamara’s University of Michigan commencement address in 1962 laying out the flexible-response doctrine and his 1967 doctrine on missile defense, Nixon administration Defense Secretary James Schlesinger’s announcement of a new doctrine in January 1974, or the discussion surrounding President Jimmy Carter’s Presidential Directive 59.[61] Understandably, these public declarations are analyzed to better understand the role of nuclear weapons in American grand strategy. Interpreting policy rhetoric is always challenging, however, especially when nuclear strategy is involved. These speeches and documents were often vehicles to send signals to a variety of audiences — domestic, allied, and adversarial — that involved assurance, reassurance, inhibition, and deterrence missions.[62] Cameron notes that American policymakers frequently played a “double game,” struggling to “balance the demands of presenting a front of strategic coherence” when, behind the scenes, things were far more complicated and uncertain.[63] Many public missions and messages of nuclear strategy were at cross purposes. For example, “the rhetoric of flexible response … was convenient to top U.S. policymakers for reasons that had little to do with enhancing deterrence or winning a nuclear war.”[64] And, as will be discussed further, nuclear rhetoric is often imprecise, unrealistic, and easily drained of meaning. [quote id="4"] The third strand is the operational history of the United States and nuclear weapons. The United States devoted enormous resources to develop certain kinds of nuclear weapons systems, deployed in surprising ways and places, as part of often-extraordinary strategies. It is critical to understand what weapons were developed and why, where and how they were deployed and targeted, and in what strategies. This history is closely guarded, but these operational decisions appear to have been driven by a complex brew of technological factors, alliance relations, and geopolitical competition, as well as bureaucratic and organization interests and domestic political considerations. The intellectual history, as told by the “Wizards of Armageddon,” and the rhetorical history laid out by political leaders often bears little resemblance to the acquisition, deployment, and use plans developed as core parts of U.S. grand strategy. As the historian David Alan Rosenberg argues, “nuclear strategy does not, in reality, consist of concepts or even policy statements. It consists of concrete decisions regarding war plans, budgets, forces, and deployments.”[65] The fourth strand of history is both the most important and the most obscure: presidential history. The structure, laws, and customs of war-making in the United States combined with the unique characteristics of nuclear weapons provides the president extraordinary power and singular responsibilities over nuclear weapons.[66] What a president thought about nuclear weapons — whether and under what circumstances he might threaten or even use nuclear weapons — is of fundamental importance. How can scholars get at these beliefs and how they informed decisions?[67] How did such beliefs change over time — both across and within administrations? How did thinking about nuclear use — or avoiding nuclear use — shape particular decisions about larger issues surrounding U.S. foreign policy and grand strategy? Even when the question of using nuclear weapons was not explicit, it no doubt cast a shadow over multiple policies. Understanding and reconstructing this past is extraordinarily difficult.[68] What is one to make, for example, of Nixon’s loose rhetoric about nuclear use in private, when his actions and policies often revealed quite careful and responsible considerations? Or Dean Acheson’s advice to President John F. Kennedy that he never reveal whether or not he would use nuclear weapons? As former Secretary of Defense Robert McNamara told Rosenberg,

nuclear strategy…is determined by the President’s views and intentions, not by policy or planning documents, or even force structures. The President alone determines how nuclear war will be fought, by virtue of his position in a highly centralized command and control structure.[69]

Reconstructing America’s nuclear past and explaining how it both shaped and was shaped by U.S. grand strategy is a daunting task. It demands integrating all four strands of this history, while deconflicting contradictory elements and assessing what forces and factors are most important. It also requires figuring out how nuclear history interacts with, and is distinct from, other powerful historical forces as varied as regional rivalries, decolonization, and the Cold War. This task is made all the more difficult by the challenges laid out in the next section: Ultimately, the past scholars and analysts are exploring is a history that never happened and thus cannot be observed, analyzed, or measured — the history of thermonuclear war.

III. A Loss for Words?

It should not be surprising that neither international relations theory nor history has satisfactorily explained the role of nuclear weapons in American grand strategy. Two reasons for this are baked into the nature of the nuclear enterprise. First, nuclear weapons present profound and often unsettling moral challenges that can make discussing their role in grand strategy difficult and divisive. It can also cause scholarship to bleed into advocacy. Second, there are profound methodological challenges in trying to understand the role of nuclear weapons. When scholars analyze the role of nuclear weapons in American grand strategy, we are most interested in phenomena that have not occurred, such as thermonuclear war, and policy outcomes that are difficult to observe and measure — such as deterrence, assurance, and resolve — or even to prove operative. These challenges pull in different directions. Analysts understandably hold strong views about nuclear weapons, which drives them to speak with authority and passion about the role and purpose of the bomb in American grand strategy. Yet, many of these deep-seated beliefs are difficult, even impossible, to prove with history or with theory. A debate that should be marked by humility and respect is often polarizing and unproductive. Talking About the Unthinkable The moral problem surrounding nuclear weapons is basic and unsettling. How should one speak about and analyze something that is unthinkable: detonating nuclear weapons against another nation? Use of these weapons would be catastrophic. It would reflect a historic failure of policy and, in many cases, would amount to mass murder. Yet, the threat to use these weapons in a variety of scenarios — including many that do not involve an attack upon the United States or an adversary’s use of nuclear weapons — has been the backbone of American grand strategy for decades. The language used to discuss these dilemmas rarely captures the magnitude of nuclear decision-making, and both academic and policy discourse often drift into a world of insider jargon and toothless acronyms that mask the extraordinary potential consequences of this debate. More than 30 years ago, Carol Cohn highlighted “the elaborate use of abstraction and euphemism, of words so bland that they never forced the speaker or enabled the listener to touch the realities of nuclear holocaust that lay behind the words.”[70] As Michael Quinlan wisely recommended, “thinking about nuclear weapons must be constantly on the alert — the more so in the absence of historical experience to anchor and calibrate discussion — to probe behind words and customary expressions so as to recall the underlying realities.”[71] The colorless language used to describe elements of this strategy and the underlying threat of nuclear confrontation that undergirds it — deterrence, credibility, signaling, escalation — is often eerily disconnected from the realities behind the words. Nina Tannenwald observed a “disconnect between how ordinary people” thought about nuclear weapons and how academic deterrence theory discussed these issues. “These game theoretic analyses, I found, had little to say about issues of revulsion and morality.”[72] Reid Pauly has termed this “rhetorical evaporation” — whereby the words policymakers and scholars use to describe U.S. nuclear policies are drained of meaning.[73] This rhetorical evaporation goes to the heart of a grand-strategic problem the United States has faced since the start of the thermonuclear age: The most important goal of American nuclear weapons policy is to guarantee that they are never used. This policy tautology was bound, over time, to undermine the threat needed to project deterrence and arguably has driven the United States to greater and more strenuous actions to demonstrate the credibility of an action no one really believes it would take. The lack of clarity about language and meaning surrounding the purposes of nuclear weapons has consequences for policy. An October 2016 report by the Center for Strategic and International Studies connected poor morale and dysfunction among American officials responsible for nuclear weapons to the difficulties of clearly communicating what role the bomb served in American grand strategy. Looking over years of nuclear policies, the report pointed out that “a coherent narrative about the fundamental role of U.S. nuclear weapons has not been sufficiently stated and promulgated” to those in the military responsible for nuclear weapons. The report criticized how U.S. nuclear weapons policy “is described in highly sophisticated strategic logic that is not very accessible to the general public or the junior nuclear personnel.” It is filled with “concepts and jargon that are not routinely defined and explained” and focuses on “what nuclear weapons will not do,” supplemented by “descriptions of decline, reduction, and diminishment.”[74] The inability to connect these fearsome weapons to explicit U. S. interests in a convincing manner arguably plays into a culture burdened by accidents and scandal.[75] The lack of clear language to describe a willingness to do the unthinkable, in order to avoid the unthinkable, is only one challenge. It would be impossible to wrestle with these issues without engaging deep moral considerations, a stance which presents difficulties for a purely “social scientific” approach. The lines between analysis and advocacy are often easily — if understandably — blurred. Robert Jervis, the father of the nuclear-revolution framework, admirably has acknowledged that mutual second-strike capabilities may not “have been as secure as I and most others believed” in the 1980s. In May 2018, he explained:

Although I stand behind the arguments I made in The Illogic of American Nuclear Strategy and The Meaning of the Nuclear Revolution, and believe that they represent a significant scholarly contribution, they were also interventions in a fierce political debate. … I was trying to persuade as well as analyze.[76]

This moral and rhetorical challenge is especially pointed for the United States. One can imagine, for example, a state using nuclear weapons as a last resort to repel a more powerful enemy that seeks to conquer its territory. The United States, however, fields nuclear weapons to achieve a variety of goals that fall well below the level of existential, including extending deterrence over allies while inhibiting their nuclear ambitions and seeking coercive advantages during crises with adversaries. These goals require more nuclear weapons in far more aggressive strategies than simply deterring invasion or nuclear attack upon the American homeland. Relying on such profoundly powerful instruments to achieve less-than-existential goals inevitably generates credibility issues. How believable are American nuclear policies? The United States has worked hard to ameliorate these credibility concerns over the years using a variety of tactics, including diplomacy and consultation with allies, nuclear sharing, developing and deploying counterforce delivery capabilities, and a willingness to use nuclear weapons first, in addition to foreign policy and military commitments that would, in a non-nuclear world, be puzzling at best.[77] Given nuclear weapons’ fundamental role in American grand strategy, will these words, commitments, weapons, and strategies remain convincing and credible in years to come? Within decades after the close of World War II — a horrendously violent war of savage conquest and genocide — analysts began to doubt that the United States would use nuclear weapons against a bitter ideological and geopolitical rival committed to its downfall. In today’s far different world, marked by relative peace, stability, and the apparent disappearance of war between the great powers, does anyone — ally or foe — know the circumstances that would prompt the United States to use nuclear weapons? Does Russia or China believe that the United States would use nuclear weapons in response to an attack on Estonia or Taiwan, for example? How and in what ways will that matter for the future of American grand strategy? Measuring the Unobservable, Observing the Immeasurable The second, and bigger, challenge to understanding nuclear weapons and U.S. grand strategy is the methodological conundrum. The most important question surrounding nuclear weapons involves a non-event: understanding why there has never been a thermonuclear war and what lessons can be derived from this non-event to keep this streak going, preferably forever. As John Lewis Gaddis pointed out while the Cold War was still ongoing, “Anyone attempting to understand why there has been no third world war confronts a problem not unlike that of Sherlock Holmes and the dog that did not bark in the night: how does one account for something that did not happen?”[78] What factors start or prevent thermonuclear war are arguable since one has never taken place. Nuclear deterrence and assurance, in all their forms, are ultimately connected to estimates about the causes and likelihood of thermonuclear war that are difficult, if not impossible, to calculate. Social science relies on observations and measurements to identify patterns and causal paths in order to generate theories that drive predictions and inform policies. History requires accumulating, sorting, and making sense of evidence about things that happen in the world. How do you generate reliable theories, histories, and policy recommendations about phenomena for which there are few or no observations or measurements? Analysts have used a variety of plausible proxies, such as how nuclear weapons affect state behavior, both in normal circumstances and crises, but the insights of such approaches have limits. It is hard enough for scholars to find consensus on things that actually happened, such as the origins of World War I.[79] Developing a consensus about a non-event one cannot observe, measure, or assess is obviously harder. [quote id="5"] This challenge plagues any assessment of U.S. nuclear postures and their role in grand strategy. Desired outcomes such as deterrence, extended deterrence, assurance, re-assurance, and credibility are elusive and can be proven only ex post, if at all. As Quinlan notes, “We have no further empirical data about how events may run if nuclear weapons are used, or if nuclear powers come seriously to blows with one another without such use.”[80] Even if deterrence and credibility could, somehow, be observed and measured, they are characteristics and phenomena driven by intangible qualities such as fear, uncertainty, and resolve. These psychological factors depend far more on context and circumstance than the material factors that make up much of international politics. Furthermore, these are human characteristics and it is unclear how to aggregate such feelings from the level of individuals to the policies and behaviors of institutions and states. These challenges affect understanding of other important nuclear behavior, such as why states that our theories would have expected to develop nuclear weapons — a wide-ranging group that might have included Australia, Brazil, Egypt, Indonesia, Japan, Sweden, Switzerland, and Yugoslavia — never developed the bomb. Decisions against doing things — not to detonate a nuclear device during a war, not to acquire nuclear weapons — are difficult to fully assess.[81] Even though many of these phenomena are elusive, analysts intuit that nuclear weapons cast a powerful shadow over foreign policy and grand strategy. Nuclear weapons obviously matter enormously, even if precisely how cannot always be proven. Consider the heated controversy over whether and how nuclear superiority — if it could be properly measured — is important to outcomes in the world. Perhaps the best that can be done is to acknowledge, as Philip Zelikow writes, that “U.S. nuclear superiority mattered. And, at some level, it also didn’t. At times both of these propositions were, at one and the same time, true.”[82] These challenges — linguistic, moral, and methodological — should not prevent the development of rigorous theories and histories of nuclear weapons and American grand strategy. If anything, they invite working harder to surface underlying assumptions and rigorous examination of both the deductive and inductive foundations of these arguments. What is most important here is to better recognize the challenges and barriers to certainty and proceed with humility in the face of daunting questions that have profound policy consequences. As Quinlan notes, the “limitation in our knowledge ought to instill in all who make predictive statements about these issues a degree of humility not always evident.”[83] American grand strategy with nuclear weapons is based on a variety of deeply held assumptions that have rarely been tested and are difficult to prove.

IV. Worse Before It Gets Better

The incomplete understanding of nuclear history and dynamics has consequences for present and future American grand strategy. If these theories and histories are problematic or questionable, it may affect how to evaluate nuclear policies and grand strategies that are chosen in the future. Even if little changed in the contemporary nuclear landscape, it is critical to have a far better, more comprehensive understanding of the past. The circumstances and environment in which nuclear decisions are made will change enormously in the years to come. Four trends stand to be especially consequential. The Return of Geopolitics The first trend is geopolitical. World politics is changing in at least three ways that might influence how nuclear weapons and U.S. grand strategy interact. First, the structure of world politics has shifted from bipolarity during the Cold War to unipolarity in the years since the demise of the Soviet Union to the possible emergence of multi-polarity or even, as Richard Haass has dubbed it, non-polarity. Contemporary analysts and decision-makers have no experience with nuclear dynamics in such a transformed international system. Will states increase their desire for and efforts to acquire the bomb? Would states be more willing to threaten and even use nuclear weapons in a post-bipolar and post-unipolar world? This relates to the second change: the increased geopolitical assertiveness of America’s primary nuclear-armed competitors, China and Russia.[84] Both countries are modernizing their nuclear forces (albeit at different paces and in different ways), and both have made efforts to reexamine their nuclear doctrines. There are dangerous scenarios — such as a crisis over Taiwan, a clash over disputed territories in the South China Sea, or an attack on a NATO member in the Baltics — in which nuclear weapons might plausibly be engaged, either on purpose or inadvertently. Third, U.S. allies and adversaries, as well as neutral countries, will continue to make their own choices about nuclear capabilities based in part on their beliefs about the role of nuclear weapons in American grand strategy. This can take many forms. Changes in the international environment or American grand strategy, perceptions of declining U.S. credibility or power, intensifying regional rivalries, or technological developments might contribute to shifts in the global nuclear landscape. The use of nuclear weapons by regional adversaries — India and Pakistan, for example — might entangle the United States and its nuclear forces in unforeseen and unwelcome ways. Smaller, arguably less responsible countries such as North Korea or Iran could expand their nuclear programs. Geopolitical shifts are taking place today under a U.S. administration whose policies on nuclear weapons and grand strategies can most generously be described as erratic; meanwhile, America’s role in the world, regardless of who is in the White House, is uncertain. Brave New World The second trend affecting nuclear weapons and American grand strategy is technological. As Keir Lieber and Daryl Press argue in their path-breaking research, “Changes in technology … are eroding the foundations of nuclear deterrence.”[85] Three forces in particular are expected to have important consequences for nuclear weapons’ role in American grand strategy: first, changes in nuclear technology and the systems that support nuclear weapons; second, emerging technologies such as cyber and artificial intelligence; and third, the blurring of the once-stark line between nuclear and non-nuclear capabilities. Changes in nuclear technology have had and will continue to have profound consequences for American grand strategy. The nuclear-revolution school often portrays the bomb in a binary fashion: as a technology that, once achieved, needs little change or improvement. In this thinking, what matters is whether or not one possesses a bomb, not what kind one has, where it is held, or how it is delivered or supported. Analysts often forget, however, three crucial characteristics about nuclear weapons. One, as Michael Horowitz has written, “nuclear weapons and missiles are relatively old technologies,” within the reach of many if not most modern states.[86] Next, nuclear weapons are not a static technology but one that has changed and will continue to shift over time. Finally, nuclear bombs are only one aspect of the technology that affects American grand strategy. Enormous changes to intelligence, surveillance, and reconnaissance; command, control, and communications; and the capabilities to deliver nuclear bombs have had and will continue to have profound consequences for nuclear strategy and statecraft. As Lieber and Press point out, synergistic revolutions in computing power and remote sensing make nuclear forces “far more vulnerable than before.”[87] These changes will intensify in the decades to come. The United States has committed to spending more than $1 trillion on modernizing its capabilities — a remarkable commitment in a time of competing demands. Much of this modernization, moreover, focuses on advancing characteristics — accuracy, speed, stealth, and miniaturization — that could make nuclear weapons appear more usable in a crisis. This massive, multi-decade investment began during the previous U.S. administration, despite being seemingly at odds with President Barack Obama’s 2009 pledge “to seek the peace and security of a world without nuclear weapons.”[88] [quote id="6"] In addition, technologies are emerging that may influence and potentially shape the future nuclear environment. Cyber, artificial intelligence, robotics, unmanned aerial vehicles, hypersonic and directed energy, nanotechnology, and as-yet-undeveloped technologies will have unknown effects. A recent RAND study, for example, warned that “artificial intelligence (AI) might portend new capabilities that could spur arms races or increase the likelihood of states escalating to nuclear use — either intentionally or accidentally — during a crisis.”[89] Cyber presents similar challenges. As a recent Chatham House report explained,

During peacetime, offensive cyber activities would create a dilemma for a state as it may not know whether its systems have been the subject of a cyberattack. This unknown could have implications for military decision-making, particularly for decisions affecting nuclear weapons deterrence policies. At times of heightened tension, cyberattacks on nuclear weapons systems could cause an escalation, which results in their use.[90]

These capabilities would have direct bearing on the role and use of nuclear weapons in American grand strategy. Meanwhile, the United States has already developed impressive non-nuclear and non-kinetic weapons capable of carrying out missions that were once the sole provenance of the bomb, including holding an adversary’s nuclear capabilities at risk. This shift has the potential to blur the line between conventional and nuclear war. As Rovner points out, there is an increasing worry that “inadvertent escalation may occur when conventional attacks put the adversary’ s nuclear force at risk.”[91] Caitlin Talmadge argues that American military action could easily be misunderstood by China as a direct threat to its retaliatory capabilities, and so “Chinese nuclear escalation in the event of a conventional war with the United States is a significant risk.”[92] New technologies, combined with how the United States has prosecuted its recent wars, may leave a nuclear adversary uncertain as to whether its nuclear forces are being targeted for elimination, possibly inciting “use it or lose it” pressures. Michael Kofman controversially suggests that, “The Pentagon remains wholly committed to the fantasy of having conventional wars with nuclear states, where they will let us win, accepting defeat without a nuclear exchange.”[93] How should one think about conventional capabilities — or non-kinetic tools — that potentially blunt or eliminate a country’s ability to use its nuclear weapons? How to define and respond to a cyberattack that undermines a country’s secure deterrent yet did not kill or injure a single person? Much existing analysis of the role of nuclear weapons assumes a stark divide between nuclear and non-nuclear conflict, a distinction that may become dangerously cloudy over time. According to Andrew Krepinevich, “The firebreak between conventional and nuclear war is slowly disappearing.”[94] As a recent study explained,

The future of nuclear deterrence is complicated further by the proliferation of conventional military technologies that may undermine traditional modes of escalation management, and as a consequence, nuclear stability. Much attention has already been given to the possible effects of several such technologies, to include stealthy unattended ground sensors, uninhabited aerial vehicles, micro-satellites, and ballistic missile defenses. Comparatively little attention, however, has been given to the possible implications of autonomous systems and artificial intelligence for nuclear stability.[95]

As James Acton perceptively notes, the “emerging interactions between nuclear and nonnuclear weapons … may prove to be a defining risk of the current nuclear age.”[96] Un-usability and Its Consequences The third trend is global public opinion. While the major nuclear powers are modernizing their forces, much of the rest of the world has been clamoring for a reduction — indeed elimination — of nuclear weapons. As Nina Tannenwald explained in her magisterial study, The Nuclear Taboo, outside of the nuclear powers, “nuclear deterrence has not been viewed as a legitimate practice for most of the other states of the world.”[97] This is not new. Since the start of the nuclear age, many non-state actors and governments have lobbied fiercely for nuclear reductions and disarmament. Nearly three decades after the Cold War ended, however, much of the non-nuclear world questions why more progress has not been made toward ridding the world of the bomb. As Heather Williams, Patricia Lewis, and Sasan Aghlani make clear, “civil society groups and the majority of states have not yet given up on nuclear disarmament.”[98] Pope Francis has declared that “Nuclear deterrence and the threat of mutually assured destruction cannot be the basis for an ethics of fraternity and peaceful coexistence among peoples and states.”[99] In 2017, the U.N. General Assembly passed a treaty prohibiting nuclear weapons. This emerged in large part from the popular global campaign to highlight the humanitarian impact of nuclear weapons. Conversations about nuclear weapons take a much different form in Sydney, Rio de Janeiro, Cape Town, or Vienna than they do in Washington, D.C. It is hard to assess how and to what extent emerging global norms will shape U.S. policies in the years to come. Tannenwald has identified the power of the nuclear taboo on state behavior, and John Mueller has highlighted the rise of powerful norms on issues such as slavery and dueling that could eventually affect not simply nuclear use but also nuclear possession. Norms and public opinion may not be determinative, but they also cannot be ignored. Tannenwald’s work suggests that even in states with nuclear weapons “national leaders do take the notion of world opinion seriously.”[100] There may come a time when the majority of the world sees merely possessing nuclear weapons, let alone using them, as wrongheaded and immoral. This relates to a fourth trend: the consequences for American grand strategy of the decreasing credibility of threats of nuclear use that undergird nuclear deterrence. Short of a “bolt from the blue” nuclear attack by an adversary — and possibly even then — how does one evaluate and assess the credibility of U.S. threats to use nuclear weapons? The probability of an invasion of the United States has not increased. The credibility issues surrounding U.S. nuclear guarantees to allies — a deep challenge even during the Cold War — may increase over time. Tannenwald captures this dynamic well:

Even though US leaders came to believe that nuclear weapons should not really be used, they were not willing to give up nuclear deterrence. But they were caught in the paradox recognized early on by nuclear strategists: making deterrence credible (especially in the face of the threat of mutual assured destruction) required convincing the adversary that the United States would actually use such weapons. As such threats became less credible over time for both deterrence and normative reasons, more numerous and more elaborate strategies were sought in an effort to bolster credibility.[101]

There is conflicting evidence about Americans’ willingness to support the use of nuclear weapons. A report chaired by the former commander of America’s strategic nuclear forces posited that “There is no conceivable situation in the contemporary world” where it would be in either Russia’s or the United States’ “national security interest to initiate a nuclear attack against the other side.”[102] Important studies suggest that Americans would support nuclear use under certain circumstances,[103] while other evidence suggests that in simulated crises it has always been difficult to get approval to use nuclear weapons.[104] If elite wargames designed and played by Thomas Schelling, Henry Kissinger, and others in the 1960s found it extremely difficult to get players to initiate a nuclear war, even when the games were rigged to make nuclear use easier, how likely are scholars today to get anyone to think about using nuclear weapons? That nuclear use is becoming increasingly unthinkable is obviously a good thing. If the bomb is unusable, however, an American grand strategy that relies heavily upon nuclear weapons to achieve many of its key missions may be increasingly untenable. Collectively, these trends should make understanding the role of nuclear weapons in U.S. grand strategy even more difficult in the years to come — and more critical.

V. Resisting the Revolution, or Revolution à la carte

Why is a grand-strategic lens the best way to understand nuclear weapons and their consequences, especially in the case of the United States? And how best to understand the role and purpose of nuclear weapons in American grand strategy? There are two criticisms of using a grand-strategic approach to America’s nuclear weapons policies. First, some are skeptical of the concept of grand strategy, arguing that it falsely conveys a picture of policy coherence.[105] This lack of coherence marks U.S. policy in particular.[106] Second, as discussed above, many believe the transformative power of nuclear weapons reduces and even eliminates the choices that leaders and states can make. The power of nuclear deterrence and the reality of mutual vulnerability remove many of the grand-strategic options and maneuvers available to states in nuclear competition, tying the hands of leaders. While there is some merit to these critiques, they are not ultimately convincing. Although it is unable to overcome all of the methodological, linguistic, and normative challenges surrounding nuclear behavior, grand strategy does recognize an obvious, but often overlooked, point: that nuclear weapons are, first and foremost, tools for states to accomplish their goals in the world. These goals, and the capabilities to achieve them, vary significantly across time, countries, leaders, and circumstance. A grand-strategic frame best captures such variance, as well as the radical uncertainty, risk profiles, trade-offs, moral challenges, and unintended consequences that policymakers face when deciding about an unknowable future.[107] Grand strategy recognizes the “crucible of uncertainty and risk” where decisions are made.[108] [quote id="7"] What insights might a grand-strategic lens provide about the role of nuclear weapons in U.S. policies? Considered broadly, the most important observation is that the United States never fully accepted the consequences of the nuclear revolution. In fact, the United States has, from the start of the nuclear age, worked eagerly to resist and overcome many of the revolutionary consequences of the bomb. It has done so with one overriding goal: to escape vulnerability — to the extent possible — and to obtain and maintain the greatest freedom of action it could to pursue its grand-strategic interests in the world.[109] This should not surprise anyone. Since 1945, the United States has been the leading power in the international system, at times possessing conventional military, economic, and cultural-ideological capabilities far in excess of any other state. Creating strategic stability, maintaining the international status quo, and avoiding war were not the only goals of American grand strategy since 1945, nor were they always the most important objectives. Many times, the United States wanted to avoid being deterred and constrained by the bomb.[110] Nuclear deterrence, remember, looks one way to a status quo, medium-size state that lacks global ambitions and whose primary concern is to avoid being invaded, conquered, or intimidated. It looks different to the most powerful state in the system, one facing no risk of invasion or conquest and whose conventional military and economic strength, absent nuclear deterrence, would allow it great freedom of action (and far less vulnerability) in the world. It is natural that the United States would seek to resist deterrence and get around the constrictions the bomb effectively places on its freedom of action. It was not always obvious, however, how this extremely ambitious goal could be achieved. American policymakers faced fateful choices, and few actions were pre-ordained. In the years after World War II, for example, American leaders could have invested their enormous political capital in pursuing nuclear disarmament or international control of the bomb.[111] At the other extreme, the United States might have launched preventive attacks against the Soviet Union and its nascent nuclear capabilities, while threatening to do the same to any other country that attempted to develop nuclear weapons.[112] Both options were at least discussed and ultimately dismissed. In later years, American leaders could have developed policies that relied less on extended nuclear deterrence by building up conventional forces that matched those of the Soviet Union in Central Europe. Or U.S. policymakers might have encouraged Western European and Asian allies to acquire and develop their own nuclear capabilities, which would have guaranteed their security without an expensive American military commitment that exposed the United States to attack. During the 1970s and 1980s, the United States could have abandoned arms-control efforts and engaged in a quantitative arms race with the Soviet Union; or American presidents might have avoided massive investments in qualitative improvements in nuclear capabilities and simply embraced parity and mutual vulnerability. These were plausible options available to U.S. presidents for how nuclear weapons would be incorporated into grand strategy. How were these choices made, and how should the alternatives be evaluated? This question should be the focus of renewed research by historians and international relations scholars attempting to understand and evaluate America’s choices with the bomb. While one purpose of America’s grand strategy is to overcome the constraints of nuclear deterrence, this goal was pursued in ways that often appear to be in tension, even contradiction, with each other. At times, U.S. leaders pursued what might be labeled “nuclear activism” — the idea that nuclear weapons are crucial instruments of statecraft and that advantages in capabilities versus adversaries were both achievable and would translate into important policy outcomes in the world. This can be seen in America’s persistent and expensive efforts over the past eight decades to develop and deploy sophisticated nuclear systems in forward-leaning strategies on behalf of expansive grand missions like extended deterrence. It can also be seen in the extraordinary U.S. efforts to prevent other states from acquiring nuclear weapons. At other times, the U.S. government advocated forms of “nuclear abstinence.” Strategic stability, mutual vulnerability, and both vertical and horizontal arms control were actively encouraged. The United States went further at points, denigrating the political utility of nuclear weapons and suggesting that the burdens, costs, and dangers of the bomb were not worth it and that the world might be better off free of all nuclear weapons. For much of its nuclear history, however, the United States has put forward both nuclear activism and abstinence, as it does when it seeks strategic nuclear advantages in order to limit the spread of nuclear weapons to its friends and allies. What explains this apparent contradiction? Perhaps the best way to understand these tensions and contradictions — seeking both nuclear primacy and non-proliferation, embracing the first use of nuclear weapons while advocating a world free of them — is to imagine American policymaking as akin to the choice of a switch-hitter in baseball, deciding whether to bat right-handed or left-handed. In the end, it simply chooses the side that offers the best chance for success, defined as reducing U.S. vulnerability and increasing its freedom of action in the world. Sometimes, the choice of whether to bat left or right is obvious, whereas, at other times it has not always been clear which side — nuclear activism or abstinence — would provide the best outcomes for the United States. On the one hand, nuclear weapons provided American leaders with certain advantages. The United States developed nuclear weapons first, and for most of the nuclear age it has possessed superiority, often enormous superiority, in qualitative capabilities — if not always quantity — over any of its competitors, an advantage that is likely to persist. Nuclear weapons have, arguably, allowed the United States to pursue strategies that may have otherwise been too difficult or expensive, such as the defense of Western Europe against the Soviet Union’s large and close armies after World War II. On the other hand, the risks of a nuclearized environment are terrifying. In an international system based on deterrence, the bomb could be used by others to constrain the United States and dilute the effect of other forms of American power. As Jervis pointed out, “One could argue that it is only nuclear weapons that stand between the US and world domination, at least as far as the use and threat of force are concerned.”[113] The United States, obviously, does not reject every aspect of the nuclear revolution. After almost a half-century of murderous conflict and world war during the first half of the 20th century, the stabilizing and peace-inducing qualities of nuclear deterrence were no doubt welcome, including by American leaders. Rather, American policymakers often reject and try to overcome those aspects of nuclear weapons power that they don’t like, while maintaining those that advance their interests. Through nuclear activism and abstinence and everything in between, the United States takes an à la carte view of the nuclear revolution. Did these choices make for wise grand strategy? As explained above, it is difficult to identify and assess the causal effects of nuclear weapons on important outcomes in American foreign policy and world politics. Answering these and similar questions requires engaging counterfactual reasoning while at the same time making assumptions about the purpose and effects of nuclear weapons.[114] These conjectures are almost impossible to test and verify. Perhaps great-power war would have decreased, if not disappeared, in a non-nuclear world, driven out by the increased lethality of war, demographics and interdependence, or shifting norms.[115] Maybe in a non-nuclear world, Berlin’s political status would have been easily resolved or would have been the cause of a third world war.[116] Perhaps it was the expense of the arms race that accelerated Soviet decline, or perhaps the communist state would have collapsed from its internal rot regardless of what nuclear weapons system or strategies the United States did or did not deploy. In a postwar world with a less engaged, more restrained United States, more independent nuclear-weapons states may have emerged, with uncertain consequences. [quote id="8"] The nuclear revolution — and America’s responses to it — also may have transformed other elements of U.S. grand strategy in ways that are underappreciated. The power of nuclear deterrence and the dangers of escalation in the nuclear age may have shifted by who, how, and for how long the United States prepares to fight with conventional weapons. American leaders have been obsessed with demonstrating resolve and credibility since 1945, including pursuing military action in areas of the world where it was difficult to identify vital U.S. interests. Would the United States invest blood and treasure in Southeast Asia, for example, in a world without nuclear weapons? Would it still have fought two costly wars in Iraq? Even where nuclear weapons are not explicitly engaged, they cast a long shadow over grand-strategic decisions. Even with all these caveats, and recognizing numerous self-inflicted wounds and disastrous military interventions, one can imagine grand-strategic choices surrounding nuclear weapons with far worse outcomes. After all, the United States prevailed in its Cold War struggle against the Soviet Union without a nuclear exchange or great-power war. It maintains extraordinary power and influence in a world where the streak on nuclear non-use has continued and where, despite dire predictions to the contrary, the number of nuclear-weapons states remains in the single digits. It is not hard to construct plausible alternative histories with far graver outcomes. That said, it is right to ask whether the United States’ heavy reliance on the bomb in its grand strategy has outlived its utility.

Conclusion

No man ever steps in the same river twice, for it’s not the same river and he’s not the same man. –Heraclitus

"Here we go again." "It’s Groundhog Day with North Korea." "We’ve seen this script before." These sorts of refrains have been common among North Korea watchers — and those who play them on TV — ahead of the summit slated for June 12 in Singapore between North Korea’s leader, Kim Jong Un, and President Donald Trump. After significant brinkmanship over whether the meeting would take place, the on-again, off-again summit looks likely to be held as originally planned. The United States has engaged North Korea in two major denuclearization processes, not to mention separate inter-Korean and multilateral efforts, over the past quarter-century. All have failed to produce the complete, verifiable, irreversible denuclearization that the United States has sought on the Korean Peninsula.[1] Some skeptical of the bilateral summit charge that this history of failure is likely to repeat itself. Meanwhile, optimists suggest that something new in the upcoming process has opened the possibility of a different outcome.[2] History can be a useful guide to avoid repeating mistakes, but events are rarely as neat and tidy as a sound bite seems to suggest. The history of nuclear negotiations between Washington and Pyongyang, as well as multilateral discussions such as the six-party talks, is far more complex than most voices in the media and policy circles acknowledge. This history offers cause for pessimism, optimism, and caution about current prospects for denuclearization.[3]

Pessimism: Denuclearization Is Harder Now Than During Past Efforts

Many of those who are pessimistic about the Trump-Kim summit point to failed efforts to achieve complete, verifiable, irreversible denuclearization and ask why this time should be any different. In one sense, the pessimists are not pessimistic enough. North Korea’s nuclear program has advanced significantly since the last major diplomatic efforts at denuclearization. In the intervening years, the possibility of denuclearization has become even more distant. This section contrasts the situation today with the state of the North Korean nuclear threat when the 1994 Agreed Framework and the joint statement of the 2005 six-party talks were reached. Seen through that lens, contentions that history may repeat itself underestimate the current challenge. In Brief: The Agreed Framework and Six-Party Talks There have been two major diplomatic efforts to eliminate North Korea’s nuclear program. In the early 1990s, North Korea initiated an international crisis by taking provocative steps toward developing a nuclear bomb: removing fuel rods from its five-megawatt plutonium reactor at Yongbyon and initiating its withdrawal from the nuclear Non-Proliferation Treaty, in which North Korea had legally pledged to forego nuclear weapons. The United States engaged Pyongyang in an effort to resolve the crisis, and the two sides signed the Agreed Framework in 1994. In short, North Korea agreed to freeze its nuclear program in exchange for energy and economic assistance, security guarantees, and political promises, including specific efforts toward the normalization of bilateral relations.[4] The Agreed Framework faced challenges in implementation, however, and collapsed in late 2002 and early 2003. The United States, North Korea, South Korea, Japan, China, and Russia initiated the six-party talks later in 2003.[5] Seeking to distinguish between the 1994 framework’s temporary freeze on nuclear production and a more comprehensive and lasting goal, the six countries announced, after two years and four rounds of negotiations, that they “unanimously reaffirmed that the goal of the Six-Party Talks is the verifiable denuclearization of the Korean Peninsula in a peaceful manner.”[6] The 2005 joint statement of those talks laid out the basic principles of a nuclear deal that would be refined more specifically in a pair of implementation agreements two years later. In late 2008, however, the participating countries reached an impasse over important technical verification issues. Whereas in 1994 North Korea had pledged to freeze its nuclear program, in 2005 Pyongyang promised to abandon all nuclear weapons and programs in exchange for energy and economic assistance, security guarantees, normalized diplomatic relations, and negotiations toward a “permanent peace regime.”[7] Although the two sets of negotiations were different in important ways, the broad structure was consistent: North Korea promised to move away from nuclear weapons in exchange for a similar basket of incentives. Denuclearization Today The North Korean nuclear program of 2018 is not the nuclear program of 1994, when Washington and Pyongyang negotiated the Agreed Framework. It is not even the nuclear program of 2005, when the six-party talks produced its joint statement. Since these diplomatic milestones, Pyongyang’s nuclear development and long-range missiles have advanced in major ways, crossing a series of critical technical barriers. These programs have grown significantly more difficult to reverse since earlier denuclearization efforts were underway. Since the 1990s, North Korea’s nuclear weapons program has grown from a theoretical capability to an actual one. North Korea’s first nuclear test occurred in 2006, a year after the joint statement of the six-party talks was released. Before this, the North Korean leadership could not be confident that their efforts to build a nuclear bomb would actually work. Indeed, the North’s first nuclear test produced more of a whimper than a bang. The explosion yielded less than one kiloton, prompting a variety of theories about why it had been a low-yield test. As such, the fundamental challenge for these earlier negotiations was to prevent North Korea from building a nuclear weapon and to persuade Pyongyang to roll back its attendant programs. These efforts resembled something like the more recent nuclear negotiations between Iran and the five permanent members of the U.N. Security Council and Germany in the sense that American negotiators and their allies could capitalize on North Korea’s uncertainty about whether it could succeed in building a bomb and crossing the nuclear-weapons threshold. Today, by contrast, North Korean leader Kim Jong Un controls a nuclear arsenal that has benefited from six tests. His is not a start-up business seeking proof of concept but, rather, an established enterprise with a demonstrated ability to detonate increasingly powerful nuclear weapons. After the 2006 nuclear test produced a lower-than-expected yield, then-leader Kim Jong Il ordered a second test, in 2009, that erased any doubt about North Korea’s basic ability to build and detonate a nuclear weapon.[8] North Korea’s third nuclear test, in 2013, came amid Pyongyang’s pronouncements that the test provided critical information that would help the regime’s effort to miniaturize a nuclear weapon in order to mount it on a missile. The third test may also have utilized uranium in its bomb design. The regime’s previous tests used plutonium, thus, testing weapons using this second path to the bomb expanded its capabilities. North Korea’s fourth test, in 2016, demonstrated the country’s thermonuclear capability for the first time.[9] The fifth and sixth tests, in 2016 and 2017 respectively, sought bigger yields still.[10] Rather than preventing North Korea from crossing the nuclear-weapons threshold, the denuclearization challenge has become much harder: Somehow, the genie must be put back in the bottle. [quote id="1"] Meanwhile, North Korea has steadily advanced its ability to develop, test, and field operational ballistic missiles that can deliver nuclear weapons. Critically, the regime has diversified its ballistic missile force to create a survivable second-strike capability, thereby securing an essential element to deter its primary adversary, the United States.[11] In 1994, North Korea was capable of striking some American bases and allies but not the U.S. homeland. That year — the same year Washington and Pyongyang signed the Agreed Framework — North Korea began producing its Nodong medium-range ballistic missile and fielded the missile the following year. The Nodong could strike South Korea and most of Japan but still not the United States.[12] In 1998, North Korea flight-tested its Taepo Dong-1 prototype, which flew over Japan, rattling the Japanese government in particular and accelerating Tokyo’s cooperation with Washington on missile defense. The flight test ushered in a new round of missile diplomacy between the United States and North Korea. Pyongyang maintained a unilateral moratorium on long-range-missile flight tests for six years, refraining from launching another Taepo Dong rocket until 2006.[13] As the two sides negotiated the Agreed Framework and, later, the joint statement of the six-party talks, North Korea did not have the capability to hit the United States with its missiles. Today, however, North Korea is perilously close to having a demonstrated delivery vehicle to strike the continental United States with nuclear weapons. Since coming to power in December 2011, Kim Jong Un has ordered scores of missile launches, including long- and short-range ballistic missiles. Both long- and short-range ballistic missiles can test technologies used in the development of intercontinental ballistic missiles (ICBMs).[14] In 2017, North Korea conducted three ICBM flight tests. After the third test, Kim Jong Un declared his nuclear deterrent complete.[15] While this claim was probably premature,[16] Kim expressed confidence that his country had attained a complete package of miniaturized nuclear weapons and survivable delivery vehicles that could reach the continental United States.[17] The main components of North Korea’s fissile material production have also shifted significantly. In the leadup to the 1994 Agreed Framework, North Korea had only one fissile material production site: the plutonium program at Yongbyon. The site was known, surveilled, and, in theory, could have been verifiably frozen with reasonable confidence. By the time of the six-party talks, the United States was aware of a nascent and covert North Korean uranium enrichment program that violated its Agreed Framework pledges. The CIA publicly disclosed to Congress its judgment that North Korea had started this program in 2000.[18] Other assessments date the origins of Pyongyang’s uranium enrichment as early as 1996.[19] Regardless of whether Pyongyang started its uranium enrichment program then or in 2000, plutonium production was North Korea’s sole route to the bomb in 1994 and its primary but not exclusive nuclear production capability in 2005. Today, North Korea acquires substantially more fissile material for weapons from its well-established uranium enrichment facilities than it does from its plutonium program. Pyongyang’s uranium program also has more growth potential than its plutonium program in absolute terms. One unclassified research project estimated that by 2020, North Korea’s only five-megawatt reactor at Yongbyon could produce 14 nuclear weapons from plutonium, while two centrifuge plants could produce about 56 weapons from uranium.[20] Put another way, the North Korean uranium enrichment program produces far more fissile material for nuclear weapons today, and its higher annual output is central to the growth of Pyongyang’s arsenal over time. When it comes to trying to negotiate verifiable denuclearization, the distinction between the plutonium and uranium routes to the bomb is critical. In 2010, North Korean officials showed the uranium enrichment facility at Yongbyon to a prominent U.S. nongovernmental delegation. The manner and speed of the facility’s construction suggested strongly that this was not the country’s first enrichment facility.[21] Commercial satellite imagery and other publicly available sources offer no proof of a third enrichment facility, but that should not provide much comfort. It is not clear how many uranium enrichment sites North Korea has because they are easier to hide than their plutonium counterparts. [quote id="2"] This should concern American policymakers as verification was the shoal upon which the six-party talks foundered.[22] During those talks, Washington wanted to conduct soil and nuclear waste samples to verify North Korea’s claims; Pyongyang refused. The “Second Phase Actions for the Implementation of the September 2005 Joint Statement,” agreed to on Oct. 3, 2007, outlined what would be required of North Korea to disable its five-megawatt reactor. The agreement did not explicitly require North Korea to allow these samples to be taken but stipulated that disablement would proceed in a “verifiable” manner.[23] Washington interpreted this to mean it could use sampling to verify Pyongyang’s actions under the second-phase agreement before it proceeded. Pyongyang, however, saw things differently: It wanted to save the issue of sampling for a “third phase” agreement, at which point it could either demand additional concessions and use the sampling issue as a bargaining chip, or not agree to sampling at all.[24] Verification is, of course, central to any sustainable agreement. And the devil is in the details. These kinds of technocratic aspects, which political leaders tend not to ponder, have derailed high-level, multiyear diplomatic initiatives. Diplomatic efforts could again sink over critical technical details if negotiators do not learn from the past. While Kim Jong Il may have hoped during negotiations in the 1990s and again during the six-party talks that his and his father’s decades-long efforts to develop nuclear weapons would someday provide a deterrent against U.S. invasion, his son, Kim Jong Un, has this capability. In the past, North Korea’s nuclear program was aspirational. Today, it is an active part of the country’s national defense. Before, verifying a deal focused primarily on a plutonium program was difficult. Now, the prominence of the uranium program in addition to the plutonium program makes the challenge even greater. It is not the same river.

Caution: New Leaders on Both Sides

In addition to the technical advancements in Pyongyang’s nuclear program since the last two major diplomatic efforts, important political changes have taken place in North Korea and the United States. During the Agreed Framework negotiations and the six-party talks, Kim Jong Il was effectively at the helm. Although North Korea’s founder and charismatic leader, Kim Il Sung, was in power until his death in 1994, and famously held important roles such as receiving former President Jimmy Carter in Pyongyang amid the crisis, Kim Il Sung told a Western reporter that by 1992 his son was running the country.[25] Kim Il Sung tapped his son as his successor in 1980 and gradually shifted power to him. As such, the Agreed Framework and six-party talks were, for North Korea, essentially a Kim Jong Il production. Today, Kim Jong Un is in charge and his personal stamp can be seen on nuclear diplomacy. Kim the youngest differs substantially in ruling style and approach from his father, something that matters greatly for the current round of summits. Kim Jong Il was an introverted micro-manager. Living in the shadow of his larger-than-life father, North Korean founder Kim Il Sung, Kim Jong Il closely controlled process and avoided public appearances. While Kim Il Sung was known for his charisma, Kim Jong Il could not even manage to give the annual new year’s day address. Instead, he instituted a policy of publishing the annual statement as an editorial in three newspapers.[26] Imagine if an American president decided to forego the annual State of the Union address and instead published his views on the White House website. That would be less of a break from past precedent than Kim Jong Il’s decision. Kim Jong Il gave one — or possibly two — extremely short speeches in his entire tenure. He was also absent from public view during the first three years of his formal reign, citing the traditional mourning period after his father’s death. Kim Jong Un is a different kind of leader. He has explicitly modeled himself after his still-revered grandfather rather than his relatively unpopular father.[27] He has brought back the annual new year’s day address. He appears in public with his wife, Ri Sol Ju, something Kim Jong Il had avoided. Kim Jong Un has also resurrected the Korean Workers’ Party, restarting the long-defunct party congresses. Tapes smuggled out of North Korea in the 1980s showed Kim Jong Il privately expressing insecure views of his personal stature that are consistent with his psychological profile.[28] In contrast, Kim Jong Un exudes confidence and has shown himself ready to personally lead the current round of nuclear diplomacy through a series of summits with South Korea, China, and the United States. It is natural and appropriate to look to the history of U.S.-North Korean and multilateral denuclearization efforts for insights into the upcoming talks. First, however, one must consider whether Kim Jong Un is following his father’s playbook. On the critical issue of his ruling style, Kim Jong Un has parted ways with his father. It stands to reason, then,[29] that his priorities and methods concerning nuclear diplomacy may not be a carbon copy of his father’s approach. Kim Jong Un proposed summit diplomacy with Trump, rather than having lower-level officials work toward a possible capstone summit by hashing out the details first. The younger Kim has taken the political risk upon himself and made it more difficult to blame subordinates for possible diplomatic failure. Leaders are always important in high-stakes diplomacy, but the summit approach makes their personality and predilections even more central to the outcome. The United States is only at the head of a long trail of diplomacy, and it is not at all clear that previous journeys foreshadow the current one. On the American side, there is also a new sheriff in town. The United States negotiated the Agreed Framework and the joint statement of the six-party talks under Presidents Bill Clinton and George W. Bush, respectively. Their administrations had different views on diplomacy with North Korea. Senior members of the Bush administration criticized the Agreed Framework negotiated under Clinton, which suffered a number of implementation challenges, including — but not limited to — the revelation of North Korea’s nascent uranium enrichment program.[30] The differences between the two U.S. administrations were stark enough that some insiders dubbed the Bush administration’s approach “ABC — Anything But Clinton.”[31] The Bush administration, however, quickly shifted to its own diplomatic effort with the North Koreans after the final collapse of the Agreed Framework. This time around, there were more seats at the table, different areas of emphasis, and intra-government intrigue,[32] but two things remained constant: the basic parameters of seeking a complete and permanent denuclearization of North Korea, and recognition that this would require some reciprocal and unpopular concessions. With a few notable exceptions, the two U.S. administrations operated — at the most general level — alike. [quote id="3"] Donald Trump fashions himself a new kind of political leader. His engagement in tit-for-tat rhetorical barbs in 2017 — such as when he threatened to bring down “fire and fury”[33] on North Korea, or when he called Kim Jong Un “little rocket man”[34] — marked an outlier for American presidential behavior. Trump’s public comments about military options — including limited military strikes that could not denuclearize North Korea by force but, it was hoped, would push Kim Jong Un back to the negotiating table — prompted substantial criticism about the wisdom of such an approach.[35] Trump quickly shifted gears in 2018, however, by accepting Kim Jong Un’s summit invitation, conveyed through the South Korean president. He has sent Mike Pompeo to Pyongyang twice — first as director of the CIA and secretary of state-designate and then as secretary of state — to advance the summit and secure the release of three unjustly imprisoned Americans.[36] Trump’s policy tools, including carrots, such as peace regime negotiations and sanctions relief, and sticks, including renewed sanctions and military moves, remain roughly the same as those available to his predecessors. But his willingness to meet Kim Jong Un early, to call off the summit, and to recommit to it within days demonstrates the greater element of uncertainty as to how the United States will begin and sustain a diplomatic process with the North Koreans. The men entering the river are different.

Optimism: Allies, Peace Regime, and Learning

Achieving complete, verifiable, and irreversible denuclearization of the Korean Peninsula is a tall order. Getting it on the cheap or for free is taller still. If success is framed in these terms alone, there is little room for optimism. If, however, progress is defined as concretely minimizing the North Korean nuclear threat and moving toward an ultimate goal of denuclearization in such a way that the benefits to national interests outweigh the costs of concessions, then there is room to be optimistic. In short, optimists can argue that a successful agreement is one that leaves the United States and its allies better off than they are in the current situation and on the current trajectory. The U.S.-South Korean combined approach, serious consideration of creating a peace regime, and the real possibility of learning from past agreements together provide reason to be cautiously optimistic about the way forward in U.S.-North Korean diplomacy. The U.S.-South Korean Combined Approach North Korea gains tactical advantage when it can split the United States from its Northeast Asian allies, specifically South Korea. The United States, South Korea, and Japan have many more shared interests and values than differences, but North Korea knows where to find natural cleavages and has traditionally sought to exploit them. North Korea has long favored bilateral diplomacy with the United States in hopes of sidelining South Korea and Japan. Tensions in the U.S.-South Korean alliance have also challenged previous efforts to maintain a united front against North Korea. Han Sung-joo, who served as South Korea’s foreign minister during the Agreed Framework negotiations, noted that then-South Korean President Kim Young-sam wanted to ensure the Americans were not “too soft” on the North Koreans. At the same time, the South Korean president did not want to raise the risk of military conflict that threatened to destroy his capital. The conservative South Korean president, worried about his domestic political support, also needed to assure his people that the United States was closely consulting him at every turn.[37] He wanted to make sure the American approach was neither too hot nor too cold at each stage of negotiations and sought to communicate this to South Koreans. The United States and South Korea were not in lockstep during the Agreed Framework, and Seoul worried about not having direct access to the North Koreans on a matter central to its national security. Kim Young-sam’s successor, Kim Dae-jung, came from the opposite end of the South Korean political spectrum and wholeheartedly endorsed engaging North Korea. Kim Dae-jung made history with the first inter-Korean summit in 2000 — just five months before the election of George W. Bush. Kim Dae-jung’s “Sunshine Policy” sought to change North Korean behavior through unconditional engagement, while Bush settled on a more confrontational approach to North Korea’s objectionable actions. Alliance managers sought to keep the two sides linked, but it remained an ongoing challenge.[38] Differences among allies are inevitable, but the combined approach provides reasons for optimism that this time may be different. Never before has an inter-Korean summit, let alone two, been explicitly set up ahead of a U.S.-North Korea summit. The South Korean presidential office recognizes that it cannot push North Korean denuclearization alone and has sought to influence U.S. engagement with the North Koreans as well as its own. South Korean President Moon Jae-in has met early success with balancing his policy of engaging North Korea while keeping the United States firmly invested in the process. The road is long, and it will become even more difficult. The two sides will face tough choices and trade-offs as the North Koreans begin to articulate their core demands. Nevertheless, Washington and Seoul have gotten off to a solid start. Peace Regime In contrast to previous diplomatic rounds, North Korea’s long-held demand to negotiate a peace treaty to replace the armistice and formally end the Korean War seems to be on the table. The Agreed Framework did not mention a peace regime or peace-treaty negotiations, but it opened the door to four-party talks —among the United States, North Korea, South Korea, and China — on these topics.[39] The Agreed Framework contained U.S. security guarantees to Pyongyang but lacked a specific and concrete quid pro quo on denuclearization and a peace regime. The 2005 joint statement promised to “negotiate a permanent peace regime on the Korean Peninsula at an appropriate separate forum.”[40] The Russians convened the Northeast Asia Peace and Security Mechanism Working Group in Moscow three times. It was one of the five working groups of the six-party talks, but it did not produce concrete outcomes. The United States favored discussing a peace regime after North Korea denuclearized, and Pyongyang did not want to wait.[41] The six-party talks, in practice, produced an agreement for denuclearization in exchange for sanctions relief and aid. Demanding that North Korea denuclearize amounts to asking it to voluntarily relinquish the world’s most powerful weapons. And reminders that its nuclear development violates international law do not move Pyongyang. Likewise, sanctions relief and aid can contribute to North Korea’s economy but would not supplant the security that it believes nuclear weapons provide. Declassified documents from Pyongyang’s socialist-bloc allies demonstrate that, in the 1970s, North Korean leader Kim Il Sung saw peace-treaty negotiations as a means to try to reduce and ultimately end the U.S. military presence on the Korean Peninsula. One of his senior party officials told a friendly foreign delegation in 1972,

The international public sees as just and honest our proposal to conclude a peace treaty between the two Koreas, to withdraw American forces and to reduce the militaries. If we conclude a peace treaty, the Americans would have no reason to stay there.[42]

The intervening four decades have produced varying assessments of North Korea’s intentions and objectives regarding peace regime negotiations. The United States will have to wait for Kim Jong Un’s articulation of his specific demands to adjudicate between competing assessments. One thing, however, is fairly certain: North Korea will seek to supplant its perceived security losses from denuclearization with phased and reciprocal adjustments to the U.S. military presence on and around the Korean Peninsula. How is this good news? Most analysts say that North Korean denuclearization is simply impossible.[43] Kim Jong Un does not want to go the way of Saddam Hussein or Muammar Gaddafi, who, lacking a nuclear deterrent, met their violent deaths after U.S.-led or -supported military operations. The peace regime issue brings to the fore difficult trade-offs and options for the highest-level decisions by elected U.S. leaders and American allies. After hearing the North Korean demands, seeking to negotiate them down, and considering the verifiable implementation measures, the United States and its allies will face a basic decision: Is the trade-off worth it at any stage? Elected leaders may have to consider difficult adjustments to the U.S. military presence on the peninsula, such as the size and scope of military exercises, strategic asset deployment, and the nature of the permanent presence in exchange for verified, late-stage steps toward denuclearization. They may decide that whatever deal is on the table with North Korea is not worth the cost, but an acceptable deal might be laid out as well. Having North Korea’s demands communicated directly from its leader to America’s is superior to wading through the many contrasting assessments of what North Korea really wants. Learning The Trump administration has the benefit of being able to learn from the past. Secretary of State Pompeo has noted repeatedly that he has read the CIA’s history of negotiations with North Korea and vowed not to repeat past mistakes. Unlike the Agreed Framework negotiators, Pompeo has historical points of reference on negotiating with North Korea about its nuclear program. One lesson is the importance of blocking North Korea from pocketing concessions. If Pyongyang can reverse its concessions, the United States and its allies must be able to do the same. This simple lesson has not been followed in earlier negotiations. In 2007, the six parties agreed to “Initial Actions for the Implementation of the Joint Statement,” which laid out in specific terms the first round of reciprocal steps to implement the 2005 agreement. North Korea pledged to disable its Yongbyon reactor, allow International Atomic Energy Agency (IAEA) inspectors to monitor the disablement, and issue a “list of all of its nuclear programs as described in the Joint Statement.” The “parallel” action from the United States included removing North Korea from its list of state sponsors of terrorism, lifting sanctions imposed through the Trading with the Enemy Act, and providing an initial tranche of heavy fuel oil as energy assistance.[44] North Korea’s disablement procedures were temporary, reversible, and intended to elicit further implementation protocols that did indeed come. When the six-party talks failed in 2008 over verification issues, North Korea was in a position to expel IAEA inspectors and move to restart the Yongbyon reactor immediately, though it delayed the restart for several years. After North Korea expelled the inspectors, the United States quickly reimposed by executive order the same authorities found in the Trading with the Enemy Act,[45] and North Korea lost out on deliveries of heavy fuel oil. The United States could not, however, reinstate North Korea on the terrorism list immediately. Once removed, relisting legally required North Korea to commit another terrorist act, and the United States did not reimpose this designation until 2017.[46] While some have argued that the United States could have relisted North Korea earlier under certain legal interpretations, the sort of “snapback” sanctions like those embedded in the Iran nuclear agreement did not exist to discourage North Korea from trying to pocket concessions in the first place. In the absence of an external enforcement mechanism or a broader relationship that keeps other international agreements on track, carefully crafted quid pro quos that have equal degrees of reversibility and importance can help sustain lasting agreements by maintaining the same incentive structure for both sides to continue abiding by the terms. [quote id="4"] Learning from history also requires a balanced understanding of past events. Since writing history is the practice of selecting which past events are significant enough to merit recording, there is always room for author bias. A one-sentence history of North Korea-related nuclear negotiations could simply note that no effort has achieved North Korea’s complete denuclearization. At this most basic level, American and allied negotiators failed to meet their core objective. If one delves more deeply, however, the history quickly becomes more complex. Both nuclear agreements delayed and degraded North Korea’s nuclear program — and a reciprocal price was paid for these concessions. The Agreed Framework verifiably froze for eight years North Korea’s plutonium program, which was its only fissile material production facility at the time of the negotiations. North Korea had three plutonium reactors under construction ahead of the Agreed Framework — one five megawatts, one 50 megawatts, and one 200 megawatts. The smallest of the three was the most developed, but the Agreed Framework effectively put the nail in the coffin of the other two.[47] Some point to a counterfactual to highlight the value of this nuclear agreement: “Experts estimate that without the Agreed Framework, North Korea could have hundreds of nuclear weapons at this point.”[48] But the Agreed Framework was a nuclear agreement, not a plutonium agreement, and North Korea cheated by initiating a uranium enrichment path to the bomb during the framework’s shaky years of implementation. The United States provided North Korea with more than $400 million in energy assistance. South Korea and Japan contributed additional significant sums through the Korean Peninsula Energy Development Organization (KEDO).[49] Concurrently, the United States and its international partners provided humanitarian assistance to North Korea during its late 1990s famine, which was never explicitly linked to the nuclear agreement. Critics charged that the aid propped up the regime amid its greatest existential crisis since the Korean War.[50] Likewise, the six-party talks verifiably shut down North Korea’s plutonium reactor for six years. It did not concretely address, however, the nascent but growing uranium enrichment threat. North Korea also received sanctions relief, some of which was not reversed until last year. Pyongyang was returned its unfrozen assets from a Macau bank and, more significantly, changed its banking practices to limit America’s ability to impose the same type of financial pain using the same tool.[51] Proponents and opponents of engagement argue about what would have happened without these agreements. But counterfactuals are a dangerous analytical tool. It is impossible to know what would have happened if one historical variable had shifted. Would North Korea have more than 100 nuclear weapons today with three functioning plutonium reactors had there been no Agreed Framework? Or would the regime have collapsed under its own weight without the Western aid? It is impossible to say. Everyone has preconceived ideas and biases, but critical readers of this history who seek to genuinely learn from the past should be equally wary of counterfactuals that support or oppose preconceived ideas.

Conclusion

A Brief History of North Korea’s Nuclear Weapons Program

The Early Years: January 1960-January 1992 North Korea’s efforts to acquire nuclear weapons began in the early 1960s, when it requested Soviet and Chinese help with developing a nuclear weapons program. Both declined, but Moscow agreed to train North Korean nuclear scientists and help Pyongyang develop a peaceful nuclear program. After China tested its first nuclear device in October 1964, North Korea approached Beijing with another request for aid in nuclear weapons development, which was again refused. Over the next decade and a half, North Korea continued unsuccessfully to seek nuclear assistance from abroad, including from East Germany, Czechoslovakia, and, again, from the Soviet Union and China. By the end of the 1970s, North Korea decided to pursue a program on its own, with Kim Il Sung ordering the development of a gas-graphite reactor at Yongbyon, which could be used to produce plutonium for nuclear weapons.[3] North Korea deliberately chose a reactor design that used natural uranium and did not require heavy water, thus minimizing dependence on external supplies.[4] Indeed, in describing North Korea’s program more than a decade later, a U.S. official observed, “Of all the nuclear weapons programs in the Third World, this is the most indigenous.”[5] By the mid-1980s, the reactor at Yongbyon was complete. Meanwhile, the United States and Soviet Union began to take notice of North Korea’s suspicious nuclear activities. In 1985, at Washington’s urging, Moscow convinced North Korea to sign the Nuclear Non-Proliferation Treaty (NPT) in exchange for a Soviet agreement to provide power reactors.[6] In September 1986, a Central Intelligence Agency (CIA) report concluded that, “whether [or not] the current nuclear developments in North Korea reflect a nuclear weapons program, they represent a considerable developing capability.” However, the same report noted, “If North Korea intends to pursue a nuclear weapons program, it has made its job much more difficult by signing the NPT.”[7] By 1988, despite having signed the NPT, North Korea still had not reached a safeguards agreement with the International Atomic Energy Agency (IAEA). Meanwhile, signs emerged that Pyongyang might be building a reprocessing facility, which could be used to extract plutonium from spent reactor fuel. This combination of red flags led the CIA to observe that “close scrutiny of the North’s nuclear effort is in order,” even though it admitted, “we have no evidence that North Korea is pursuing a nuclear weapon option.”[8] The following year, after a Washington Post story drew attention to North Korea’s reprocessing facility and potential nuclear weapons program, North Korea publicly denied that it was seeking nuclear weapons.[9] Around this time, the U.S. government concluded that North Korea was indeed pursuing nuclear weapons.[10] That conclusion was bolstered by evidence that North Korea was testing sophisticated conventional explosives at Yongbyon, indicating that Pyongyang could be developing an implosion-type nuclear weapon.[11] Over the next two years, North Korea’s sense of insecurity sharpened, as its Soviet ally collapsed and both Russia and China sought to improve relations with Seoul. Meanwhile, the United States and Russia worked to convince North Korea to accept IAEA safeguards. But Pyongyang demanded the removal of U.S. nuclear weapons from the peninsula along with a negative security assurance as a precondition for accepting any such safeguards.[12] When the IAEA Board passed a resolution in September 1991 calling on North Korea to implement a safeguards agreement, a North Korean official suggested his government would only do so if the U.S. “nuclear threat” dissipated and “if the pressure put upon us is removed.”[13] [quote id="1"] A few weeks later, as part of an initiative to cut the U.S. nuclear arsenal globally as the Cold War wound down, President George H.W. Bush announced that U.S. tactical nuclear weapons would be withdrawn from foreign bases. This led the North Korean government to announce, “If the United States really withdraws its nuclear weapons from South Korea, the way of our signing the nuclear safeguards accord will be opened.”[14] U.S. government officials around this time also were considering an initiative whereby both South and North Korea would be asked to commit to not reprocess spent nuclear fuel, which would help address proliferation risks but would go beyond North Korea’s obligations under the NPT.[15] U.S. nonproliferation efforts finally bore fruit in late 1991, when North Korea agreed to accept IAEA safeguards and reached an agreement with Seoul under which the two countries pledged not to develop nuclear weapons.[16] The leaders of North and South Korea also agreed to a nonaggression pact.[17] The nuclear agreement, formally concluded in January 1992, additionally required the two Koreas to refrain from enrichment, reprocessing, and hosting nuclear weapons, to be verified by bilateral inspections.[18] In the same month, as a gesture of good will toward Pyongyang, Washington and Seoul announced that they would cancel their joint military exercises for the year, leading North Korea to finally sign an IAEA safeguards agreement.[19] The First North Korean Nuclear Crisis: February 1992-May 1994 The momentum toward nonproliferation and improved relations on the Korean Peninsula did not last long. In February of 1992, as North Korea stalled on ratifying the safeguards agreement, U.S. officials warned that Pyongyang might only be a few months away from a rudimentary weapons capability.[20] Meanwhile, U.S. intelligence suggested that North Korea was continuing construction on its reprocessing facility, hardening it against potential attack, and perhaps removing equipment prior to inspections.[21] In the spring of 1992, North Korea finally ratified the safeguards agreement, submitted its declaration of nuclear activities to the IAEA, and allowed inspections, but this only roused further concerns. Inspectors uncovered several inconsistencies in the North Korean declaration, found evidence that equipment had been removed from the reprocessing plant (which North Korea had previously denied existed), and were refused access to several undeclared sites suspected of storing nuclear waste. IAEA analysts also determined that North Korea had likely produced more than the small amounts of plutonium to which it had admitted.[22] Over the course of that summer, the United States, Russia, China, and Europe all pressured North Korea to comply more fully with the IAEA. Meanwhile, China restored diplomatic relations with South Korea and Russia began to loosen ties with Pyongyang.[23] As an October 1992 U.S. Defense Department memo observed, “What is becoming clear is that North Korean non-cooperation is more evident as IAEA becomes more aggressive in its inspections.”[24] In early 1993, with the Clinton administration now in office, the United States and South Korea announced that they would hold their annual military exercise — which had been canceled the year before — making reference to North Korea’s lack of full compliance with the IAEA and North Korea’s failure to agree to a bilateral inspection regime with South Korea. For its part, the IAEA demanded that North Korea allow special inspections of its suspected nuclear waste storage sites, giving Pyongyang 30 days before it would refer the issue to the United Nations Security Council (UNSC).[25] In March, as the military exercise began, North Korea declared it would withdraw from the NPT in 90 days, leading the IAEA Board of Governors to turn over the issue to the UNSC. After China signaled it would not support sanctions against North Korea, the United States again turned to diplomacy, offering to hold talks with Pyongyang on a range of issues — including military exercises, security assurances, and nuclear inspections — if it would be accommodating on the nonproliferation issue.[26] Although China opposed North Korea’s acquisition of nuclear weapons, it feared that strong sanctions might cause the regime to collapse, leading to a refugee crisis on its borders.[27] Over the summer of 1993, talks with the United States led North Korea to suspend its NPT withdrawal. The United States agreed to help North Korea acquire light-water power reactors in exchange for North Korea’s cooperation with inspections.[28] By the end of the year, however, North Korea was again dragging its feet on inspections, seeking a broader grand bargain with the United States as its price for cooperation.[29] At the same time, U.S. officials concluded that North Korea may have already acquired enough plutonium for a nuclear device,[30] causing the United States to try to line up support for sanctions at the United Nations, an effort again obstructed by China.[31] After North Korea agreed to allow new IAEA inspections in March 1994, the United States and South Korea announced that they would suspend their joint military exercises and hold additional talks with Pyongyang.[32] But North Korea blocked inspectors from visiting parts of its reprocessing facility at Yongbyon, leading the IAEA to pull out its team.[33] This, in turn, led Washington to cancel scheduled talks with North Korea, announce that it would indeed hold its military exercise with South Korea, and begin reinforcing its military posture in the region, including moving Patriot missile batteries to South Korea.[34] With North Korea warning that the peninsula was “on the brink of war,” China again signaled opposition to U.N. sanctions.[35] Soon thereafter, Secretary of Defense William Perry publicly stated that a military strike was a possibility if diplomacy and sanctions failed.[36] After another U.S. negotiation attempt failed, North Korea began unloading spent fuel rods from its Yongbyon reactor, laying the groundwork for the separation of additional plutonium. In June, IAEA Director Hans Blix declared that the agency had permanently lost the capability to verify whether North Korea had diverted nuclear materials for use in a weapons program. As tensions continued to rise, the United States proposed an arms embargo against North Korea at the United Nations, while both South and North Korea prepared for possible military conflict.[37] The Agreed Framework and its Demise: June 1994-March 2003 The North Korean nuclear crisis was only defused when former President Jimmy Carter traveled to North Korea in June and met with Kim Il Sung. Carter identified a potential bargain that would involve the United States agreeing to hold high-level talks with Pyongyang in exchange for a North Korean commitment to allow IAEA inspections, to not refuel its reactor, and to refrain from further reprocessing of spent fuel.[38] A few weeks later, Kim Il Sung died and was succeeded by his son, Kim Jong Il, who finished the nuclear negotiations his father had started.[39] In October 1994, after several months of negotiations, the United States and North Korea concluded the Agreed Framework. The deal required Pyongyang to freeze operation of its nuclear facilities at Yongbyon, agree to inspections, remain in the NPT, move toward implementation of the 1992 denuclearization pact with South Korea, and not reprocess any more spent fuel. In exchange, Washington agreed to provide North Korea with heavy oil, to help it acquire two light-water power reactors, and to move toward broader improvements in relations, including increased diplomatic contacts, removal of sanctions, a negative security assurance, and, ultimately, normalization of relations.[40] By the late 1990s, however, the Agreed Framework had run into difficulties. Partly due to congressional opposition, the United States was behind in delivering the promised benefits to North Korea.[41] In particular, the United States was late in starting construction on the light-water reactors and had been repeatedly late in providing oil. It also had lifted few sanctions and had maintained North Korea on the list of state sponsors of terror. Meanwhile, there were no substantial moves toward normalization.[42] Then, in 1998, the United States detected the construction of a large underground complex in North Korea, which officials worried might be a covert nuclear site.[43] That same year, North Korea tested a new medium-range ballistic missile, the Taepodong-1, firing it over Japan and into the sea.[44] The test was especially concerning because it indicated that North Korea would soon have the ability to target all of Japan.[45] Washington responded by threatening to scuttle the Agreed Framework, leading North Korea to allow an inspection of the underground site in question. Although no evidence of nuclear activity was found, U.S. intelligence soon began to notice indications that North Korea was procuring components for an enrichment program, possibly with aid from Pakistan.[46] Indeed, around this time, North Korea began receiving assistance in enrichment from the AQ Khan network.[47] Despite these challenges, a few signs of cooperation emerged at the tail end of the Clinton administration. Clinton put former Secretary of Defense William Perry in charge of coordinating North Korea policy, who worked toward renewed cooperation.[48] Instead of confronting North Korea over its rudimentary enrichment program and threatening to pull out of the Agreed Framework, the Clinton administration decided to pursue additional negotiated agreements. After all, North Korea had technically been complying with its obligations under the Agreed Framework, which focused on its plutonium program — a far bigger proliferation threat than its nascent enrichment program at the time.[49] In late 1999, Pyongyang agreed to a missile test moratorium in exchange for the easing of U.S. economic sanctions,[50] and in late 2000, the United States and Pyongyang held a series of high-level meetings, including a trip by Secretary of State Madeleine Albright to North Korea to discuss the missile issue.[51] In December 2000, with his administration’s time running short, President Clinton decided to pause the negotiations, putting the ball in the court of the incoming George W. Bush administration.[52] [quote id="2"] The Bush administration, opposed to a policy of accommodation toward North Korea, initially halted negotiations and insisted on harsher terms, including broader inspection rights and limits on North Korea’s conventional force posture.[53] In October 2002, after the 9/11 attacks and North Korea’s inclusion in the Bush administration’s “Axis of Evil,” the United States accused North Korea of running a secret uranium enrichment program. Recriminations and threats between the two sides soon caused the Agreed Framework to break down, leading North Korea to kick out inspectors, withdraw from the NPT, and restart nuclear activities at Yongbyon.[54] The Bush administration, for its part, cut off oil shipments and suspended construction on light-water reactors in North Korea.[55] North Korean officials began citing U.S. military actions in Yugoslavia, Afghanistan, and Iraq as justifying their need to develop nuclear weapons. Indeed, there are indications that Kim Jong Il was seriously concerned about the prospect of U.S. military action in 2003.[56] Why did the Agreed Framework break down? It seems reasonable to conclude that both sides bear some of the fault. Although North Korea clearly violated at least the spirit of the agreement by starting a secret enrichment program, it is also clear that the United States was not following through on its own obligations. The key problem, as Siegfried Hecker points out, was that “Washington saw the Agreed Framework primarily as a nonproliferation agreement,” while North Korea “viewed the political provisions of the Agreed Framework, which called for both sides to move toward full normalization of political and economic relations, to be the heart of the pact.”[57] This fundamental asymmetry in how the Agreed Framework was understood may help explain both the failure of the United States to pursue broader improvements in relations in a timely fashion, as well as the North Korean decision to pursue an enrichment capability when the Agreed Framework was not playing out as it had envisioned. It also suggests that a desire for improved relations with Washington has been an important motivation for North Korean decision-makers, which perhaps implies that “carrots” are as or more important than “sticks,” in dealing with Pyongyang, a point we return to below. Crossing the Finish Line: April 2003-December 2017 Despite withdrawing from the NPT, North Korea continued to seek economic, diplomatic, and security benefits in exchange for limiting its program, threatening to test a nuclear device or export nuclear materials if its demands were not met.[58] While the Bush administration would not agree to these demands, it did begin negotiations with Pyongyang in the context of the Six-Party Talks, beginning in August 2003 and continuing until 2009. These talks were organized and hosted by China and also included South Korea, Japan, and Russia.[59] At the end of 2004, the IAEA Director concluded that North Korea likely possessed enough plutonium for four to six bombs.[60] The following year, U.S. intelligence detected the construction of a tunnel that could be used for a nuclear test, while Pyongyang continued to demand concessions from the United States, including the provision of power reactors, which had been promised in the Agreed Framework.[61] In September 2005, during the fourth round of the Six-Party Talks, North Korea committed in principle to denuclearization in exchange for political and economic concessions.[62] Nevertheless, despite this progress, the United States imposed sanctions on entities involved in North Korean weapons of mass destruction (WMD) programs and levied an array of financial sanctions intended to cut down on Pyongyang’s illicit economic activities.[63] In July of 2006, with the Six-Party Talks on hold due to North Korean opposition to America’s sanctions policy, Pyongyang tested six missiles, leading the UNSC to impose sanctions banning missile-related trade with North Korea.[64] In early October, North Korea warned it would soon conduct its first nuclear test, citing U.S. hostility and sanctions as justification.[65] A few days later, despite international warnings, North Korea conducted its first nuclear test, although the low yield suggests the device did not work as intended, measuring less than one kiloton.[66] The UNSC responded by imposing new sanctions on North Korea, covering trade in armaments and luxury goods, although provisions allowing for the inspection of North Korean cargo were weakened by Russian and Chinese opposition.[67] Soon thereafter, at Chinese prodding, Pyongyang announced it would return to the negotiating table.[68] In February 2007, an agreement was reached by the six negotiating parties, which called on North Korea to freeze its plutonium program and accept inspections at Yongbyon in exchange for the lifting of certain U.S. sanctions, the provision of fuel oil, economic aid, Washington taking North Korea off its list of state sponsors of terrorism, and movement toward normalization of relations with the United States.[69] After North Korea began to receive sanctions relief, it started to implement its side of the deal in the summer of 2007. The following summer, the Bush administration further eased sanctions, but stalled on removing North Korea’s designation as a state sponsor of terrorism.[70] In September, North Korea blocked IAEA inspectors from monitoring Yongbyon, displeased that the United States had not yet delivered some of the promised benefits.[71] After a deal was struck on verification measures the following month in exchange for North Korea’s removal from the state-sponsor-of-terrorism list, Pyongyang backtracked on the agreement, leading the United States to suspend the provision of fuel.[72] [quote id="6"] Tensions continued after the Obama administration entered the White House in 2009, with North Korea testing a Taepodong-2 missile in April of that year, which led the UNSC to tighten the enforcement of missile sanctions. North Korea responded by escalating the situation further, kicking out inspectors, pulling out of negotiations, and warning it would resume its nuclear program.[73] On May 25, 2009, North Korea conducted its second nuclear test, with a yield estimated between two and eight kilotons, leading the UNSC to pass additional sanctions, including a wider arms embargo and tighter financial restrictions.[74] The following year, Pyongyang revealed a centrifuge enrichment plant at Yongbyon, which could allow it to produce highly-enriched uranium for nuclear weapons.[75] North Korea also committed two armed provocations in 2010, sinking a South Korean vessel and shelling the South Korean island of Yeonpyeong.[76] For the duration of its time in office, the Obama administration adopted a policy of “strategic patience” toward Pyongyang, increasing the diplomatic and economic pressure on North Korea in an effort to convince the regime to return to the negotiating table while hoping for a change in regime orientation. After Kim Jong Un succeeded his father in December 2011, the United States and North Korea reached the short-lived Leap Day Agreement in February 2012, whereby North Korea temporarily limited its nuclear and missile programs in exchange for economic aid, a deal that Pyongyang soon violated. From this point onward, North Korea declined to seriously negotiate, focusing instead on building up its nuclear and missile capabilities.[77] This uncompromising North Korean posture has continued under the Trump administration, which has adopted a strategy of both sanctions and threats of preventive military force.[78] Between 2010 and 2017, North Korea conducted four nuclear tests (one in 2013, two in 2016, and one in 2017). The most recent test, in September 2017, is estimated to have well exceeded 100 kilotons in yield, suggesting North Korea has developed a thermonuclear or boosted fission device.[79] During the same period, North Korea conducted more than 80 missile tests, including several that demonstrate the country’s ICBM capability, putting the U.S. homeland within striking distance.[80] In 2017, the Defense Intelligence Agency estimated that North Korea may possess as many as 60 nuclear weapons.[81] North Korea achieved this impressive progress in its nuclear and missile programs despite steadily increasing international sanctions pressure, including six rounds of U.N. sanctions and gradually escalating U.S. sanctions.[82] The most recent U.N. sanctions, passed in August and September 2017, prohibited the import of North Korean coal, iron, lead, seafood, and textiles, and limited North Korea’s ability to buy oil and refined petroleum.[83] Yet these stronger measures have almost certainly come too late — no country has ever given up an indigenously developed nuclear arsenal of this size and sophistication.

How Did Academic Theories Perform?

Why North Korea pursued nuclear weapons is hardly a puzzle. The country finds itself in one of the most dangerous security environments in the world, facing a conventionally superior, nuclear-armed American-South Korean alliance on its borders. Since the end of the Korean War, which ended in armistice and not a peace agreement, both the North and the South have openly called for reunification. The pursuit of nuclear weapons — if it were successful — would provide North Korea with, at the very least, invasion insurance. This is not to say that there are not reinforcing domestic political motivations. Nuclear weapons have become a symbol of the Kim regime’s legitimacy and power. North Korea’s nuclear program also makes it far more relevant in global affairs than it otherwise would be, giving it a kind of status. But the primary motivation is security, to deter against a conventional invasion by the United States and efforts by South Korea to reunify the Korean Peninsula on Western terms. [84] It is somewhat surprising, then, that North Korea’s pursuit of nuclear weapons only popped on the radar screen of the United States intelligence community in the late 1980s. In 1982, a CIA report analyzing the next decade of nuclear proliferation concluded that, despite interest in reactors, “we have no basis for believing that the North Koreans have either the facilities or materials necessary to develop and test nuclear weapons.”[85] By the mid-1980s, however, North Korea’s development of a nuclear reactor started raising concern that Pyongyang might be pursuing nuclear weapons, though the intelligence community still doubted that North Korea would risk nuclear pursuit given its vulnerability and the prospect of reactive South Korean proliferation.[86] Twenty years later, North Korea would test its first fission device. Thirty years later, North Korea would undeniably become the world’s 10th nuclear weapons power. Few theories of nuclear proliferation, if any, gave North Korea a chance of reaching that milestone. Below, we catalog how academic theories fare in predicting North Korea’s chances of successfully acquiring nuclear weapons. To be clear, we focus on theories that purport to explain the acquisition of nuclear weapons (or lack thereof), as opposed to the related literature on why states pursue nuclear weapons. Moreover, we limit our discussion to theories that are intended to apply generally to all countries, as well as theories that are intended to apply to specifically to countries like North Korea. In other words, these are fair tests of the theories under consideration; we are applying the theories to a case in which they are intended to apply. [quote id="3"] Realist theories on nuclear proliferation assume that states acquire nuclear weapons for security purposes. Indeed, quantitative studies have found that states in enduring rivalries and with more military disputes are more likely to acquire nuclear weapons.[87] In their most extreme form, realist theories argue that if a state has a strong enough security imperative, nothing can stop them from acquiring the bomb. According to Kenneth Waltz, for example, “no country has been able to prevent other countries from going nuclear if they were determined to do so.”[88] Yet there is something fundamentally unsatisfying about this argument, since it is impossible to measure a state’s level of determination with any degree of certainty, thus rendering the theory tautological. If a state does acquire nuclear capabilities, it was really determined; if it does not, it must not have been very motivated. Moreover, there are many countries in highly threatening security environments that have pursued and not acquired the bomb, including South Korea, Taiwan, West Germany, Iraq, and Iran. The most complete realist model for what states might successfully acquire nuclear weapons is offered by Alexandre Debs and Nuno Monteiro.[89] They argue that states must have both a willingness and opportunity to proliferate — that means they need a security motivation to proliferate, but the breathing room to do so without facing preventive war (or the credible threat of war) from an adversary. States without reliable allies will, therefore, be more willing to pursue nuclear weapons. This is where Debs and Monteiro place North Korea. They write:

Taking stock, our strategic theory of proliferation accounts for North Korea’s nuclearization. Pyongyang’s security concerns vis-à-vis the South and the United States, combined with the absence of a reliable ally since at least the end of the Cold War, account for Korea’s willingness to proliferate. Its ability to inflict high costs on its adversaries using conventional weaponry deterred counterproliferation military action, granting North Korea the opportunity to become, as of this date, the latest state to have built the bomb.[90]

At first glance, this appears to be a compelling argument; North Korea was strongly motivated by its security predicament to pursue nuclear weapons and was able to do so because it could deter counterproliferation efforts with its conventional threat to Seoul. Yet there are a couple problems with this argument. First, there are a variety of states with similar security motivations, but which failed to successfully acquire the bomb, for example Iran and Iraq. Both countries could hold valuable American allies or assets at risk conventionally, or even worse, with chemical weapons, if the United States attempted a preventive strike. Iraq and Iran (thus far) have failed to successfully acquire nuclear weapons, yet North Korea did. Second, when applied to North Korea, the argument relies on an almost circular claim that the U.S. was deterred from taking military action against North Korea because it never carried out a military attack. Yet the United States seriously considered ordering a military strike on the Yongbyon Reactor in 1994.[91] As Van Jackson demonstrates, North Korea perceived this as a credible threat due to a combination of factors, including U.S. military exercises with South Korea and the recent use of force in the Gulf War. Indeed, according to the testimony of defectors, Kim Jong Il (then head of North Korean military forces) “spent much of March 1993 in a military bunker, issuing commands to field units, a curious action if North Korea did not anticipate the possibility of conflict.”[92] The threat of military force, combined with Jimmy Carter’s intervention and the subsequent offer of inducements, led to the Agreed Framework, which successfully froze North Korea’s plutonium program. Certainly the potential for retaliation against Seoul induced caution in American decisionmakers, yet this is beside the point, since Debs and Monteiro’s theory requires only that the proliferator perceive a credible threat of force. North Korea also likely perceived a credible threat of force in 2003, as noted above, but persisted with its nuclear program anyway. Even this more complete security model does not explain how North Korea defied the odds, when other similarly vulnerable states — all of whom had the ability to lash out conventionally or with chemical weapons — failed to acquire nuclear weapons. A strict test of the preventive war mechanism would underestimate North Korea’s probability of acquiring nuclear weapons. A second family of theories focuses on the ability of authoritarian states to successfully manage a nuclear weapons program. In short, none of these models gave North Korea a fighting chance of succeeding. The most prominent example of this theory is Jacques Hymans’s work in Achieving Nuclear Ambitions.[93] Hymans argues that authoritarian regimes, especially neopatrimonial regimes — where networks based on personal ties make up the regime and its power base — are particularly bad at managing complex projects such as nuclear weapons programs that require cooperation and coordination between scientists, industrial and engineering organizations, and the military. Dictatorships are often too paranoid and incompetent to successfully manage such projects, according to Hymans. [quote id="4"] North Korea is the poster boy for this theory. Hymans argues that North Korea “is the ideal-typical case of neopatrimonialism,” where top-down meddling in programs makes it ripe for spectacular failure in projects as complex as nuclear weapons.[94]At the time his book was published, in 2012, Hymans denied that North Korea was actually a nuclear weapons power. He wrote that the October 2006 nuclear test “was an embarrassing technical failure”[95] and the second one in 2009 “was at best only the most minimal of successes.”[96] Hymans further argued that “it remains unclear if North Korea does or does not yet have an operational nuclear arsenal that it could use in battle.”[97] However, tests are only failures if nothing is learned from them. It is clear that North Korea learned a lot from each of these tests and, in its subsequent nuclear and missile tests, has demonstrated an ability to reach thermonuclear yields in the hundreds of kilotons. It also likely has the capacity to deliver its nuclear weapons to regional targets if not the continental United States. Hymans’ theory predicts, at best, “the project’s snail’s pace of progress,” arguing that “it seems reasonable to assume that maintaining the snail’s pace would be the most North Korea could hope for. Moreover, Pyongyang has proved such an inveterate bluffer in the past that we should stop gasping in fear every time it threatens the world with yet another technological ‘breakthrough.’”[98] And yet, history has proven this argument wrong. The 2017 summer sprint in North Korea’s nuclear and missile program was a clear breakthrough — one cannot bluff intercontinental ranges and thermonuclear yields, which speak a universal language. To his admirable credit, however, Hymans develops a falsifiable and testable theory and is willing to make predictions based on it. Unfortunately, North Korea is clearly an outlier for his theory — the pathologies of the Kim regime may have stymied food production, but not the nuclear weapons program — which once again defied the theoretical odds. A second theory in this family of models is Malfrid Braut-Hegghammer’s work on Iraq and Libya, which similarly focuses on authoritarian regimes’ inability to manage nuclear weapons programs.[99] However, Braut-Hegghammer’s argument focuses not on interference in such programs, but on neglect by weak states with personalist regimes, where power is primarily invested in the hands of one leader rather than a political party or other large group. According to her theory, the capacity of weak states is often restricted by constant efforts to prevent the next coup, which leads to the neglect of projects as complex as nuclear weapons. She argues that Saddam and Gaddafi “lacked the capability even to pay close attention to the performance of these programs because they had weakened their states to strengthen their own hold on power.”[100] Drawing on principal-agent theory, Braut-Hegghammer argues that, rather than meddling in their nuclear programs as Hymans suggests, Saddam and Gaddafi failed to monitor it closely enough, allowing scientists to run their own fiefdoms and sell snake oil to these leaders, which in turn resulted in both countries’ failure to successfully develop nuclear weapons. She writes:

weak states often lack the institutional resources to set up and operate nuclear weapons programs. This is particularly problematic in so-called personalist regimes, such as Iraq and Libya, whose leaders undermine formal state institutions and seek to govern through informal structures of patronage and control.[101]

Although the Kim dynasty is clearly dominated by one-man rule and invests a lot of energy in preventing coups,[102] Braut-Hegghammer in fact argues that her theory does not apply to North Korea, which she classifies as a “strong state.”[103] This is debatable. Certainly, the North Korean regime is stronger than many observers believed, given that it has, for decades, defied predictions that it would collapse.[104] Yet if North Korea is truly a strong state, it is puzzling that it was not able to prevent hundreds of thousands (and perhaps millions) of its citizens from dying from famine in the 1990s.[105] As David Kang argued in 2012, the evidence suggests that “North Korea is both strong and weak,” and that the state has weakened further in recent decades, stating, “Largely as a result of weakened state control, the economy has experienced increases in commercialization and marketization in recent years.” This, in turn, has “shriveled the central government’s control over the periphery.”[106] Yet, precisely as the North Korean state has weakened, it has made the most dramatic strides in its nuclear weapons program. At the very least, this trend would seem to contradict the pattern expected by Braut-Hegghammer’s theory. The theories described above, which base predictions of the likelihood of acquisition on either security imperatives or regime type, in fact vastly underpredict North Korea’s probability of acquiring nuclear weapons. Similarly, supply-side or diffusion theories also fail at providing a satisfying explanation of North Korea’s nuclear accomplishments. For example, quantitative studies have found that wealthy (or at least moderately wealthy) countries are significantly more likely to acquire nuclear weapons,[107] yet North Korea acquired these weapons despite being one of the poorest countries in the world. Matthew Fuhrmann’s more nuanced supply-side argument focuses on foreign technical support, contending that North Korea “further underscore[s] the significance of the technical base resulting from atomic assistance,” with the North Koreans receiving Soviet assistance in the 1950s and 1960s.[108] The first problem with this argument is that while it might predict that North Korea would succeed, it should also predict that other countries in threatening security environments that received foreign assistance would acquire nuclear weapons, for example Germany, Japan, South Korea, and Egypt. The second issue is that North Korea did not in fact receive an especially large amount of foreign assistance. Indeed, according to the main metric Fuhrmann uses to measure foreign support — the number of nuclear cooperation agreements — North Korea received far less foreign assistance than the aforementioned countries, and also received significantly less than countries like Ireland, Portugal, and Indonesia, as well as recent proliferators like India, Pakistan, Iran, and Iraq. Matthew Kroenig’s supply-side theory emphasizes the role of sensitive nuclear assistance in facilitating nuclear acquisition, which he defines as the transfer of enrichment or reprocessing technology or bomb designs.[109] While North Korea did receive aid in uranium enrichment technology from the AQ Khan network, this does not explain North Korea’s initial acquisition of nuclear weapons, which relied on plutonium [not highly enriched uranium (HEU)] from an indigenously built reactor and reprocessing facility. Indeed, starting in the 1970s, Pyongyang had “minimal foreign assistance” to its nuclear program, using publicly available information to mimic the designs of British reactors and a Belgian reprocessing facility.[110] A related theory by Michael Horowitz argues that the diffusion of 1950s-era military technology to a state like North Korea should not be surprising.[111] Horowitz writes: “How hard is it actually for a determined proliferator to acquire nuclear weapons? The answer? Not as hard as you might expect. And this becomes clearer when you think about the acquisition of nuclear weapons in the context of other military technologies.”[112] Horowitz himself admirably concedes, however, that the diffusion argument suffers the same problem as supply-side explanations: It overpredicts success. He goes on to point out that “simply importing ‘normal’ military technology diffusion models, while helping us understand North Korea, would probably overpredict proliferation in general, particularly in light of international efforts to make weapons acquisition harder. States such as Iraq and Libya tried but failed to acquire nuclear weapons.”[113] It is not as if we, the authors of this article, were right about North Korea either. Co-author Vipin Narang, in his 2014 book on nuclear strategy, essentially punts on North Korea by claiming it was unclear what its nuclear strategy — if any — was at the time of writing.[114] In his work on strategies of nuclear proliferation, Narang argues that North Korea’s probability of success was heightened because it was able to avail itself of a “sheltered pursuit” strategy, enjoying protection first from the Soviet Union and then China. This in turn enabled Pyongyang to proliferate under the cover of its allies — developing the plutonium pathway to nuclear weapons—before shifting to a “hiding” strategy, exemplified when it cheated on the Agreed Framework to develop a secret uranium enrichment pathway.[115] Here, Narang argues that it was the protection from China that helped stave off a United States attack, not just the threat North Korea posed to Seoul. But even this argument likely underpredicts North Korea’s probability of success, because while sheltered pursuit can often succeed, North Korea’s relationship with China has been peculiar in the post-Cold War era, forcing the Kim regime to at times pursue a hiding strategy. Hiding strategies are very risky if discovered, and North Korea’s hidden program was discovered before it even tested its first fission device. What seems to have deterred the United States from attacking North Korea after the 2002 discovery of the hidden enrichment program was the fear that the North had reprocessed enough plutonium from its sheltered pursuit days for several nuclear bombs — not just the conventional threat to South Korea. Essentially, North Korea’s hidden enrichment program was discovered too late to prevent it. While this framework gets some features of North Korea’s behavior correct, the North Korean case is again unique and defies most theoretical predictions. In general, academic theories of nuclear proliferation sorely missed the mark when it comes to North Korea. It is only one case, to be sure, but it is clearly an important one. However, this sober assessment is not meant to suggest that we should abandon our efforts to theorize about the causes and process of nuclear proliferation. Of the 30 or so states that have begun nuclear weapons programs, 10 succeeded in acquiring them. In other words, it is still a relatively uncommon event, and our theories are necessarily probabilistic. Nevertheless, it is notable how few theories gave North Korea a good chance of acquiring the bomb. [quote id="5"] So what can we learn from this outlier? It is important to note here that an outlier case does not disconfirm any theory. All of the theories discussed above make significant contributions toward explaining and predicting certain cases of nuclear proliferation. With that said, it is useful to examine what adjustments to our theories might be advisable based on the North Korean case. We believe the North Korean case illustrates several dynamics worth incorporating into academic theories of proliferation. First, it shows that the threat of preventive war, even when perceived as credible, has limits as a counterproliferation tool. At several points, North Korea viewed the threat of an American attack as credible, and yet it continued its nuclear program, or else only agreed to limits on that program after receiving significant inducements (in the case of the Agreed Framework). Second, it shows that states can still successfully play a cat-and-mouse game of plausible deniability with hidden programs — as South Africa and Pakistan once did with enrichment programs, and North Korea did with both its reactor and its uranium enrichment program. Third, states that can avail themselves of a “sheltered pursuit” strategy — finding a great power patron, although not necessarily an ally, that is willing to essentially underwrite its illicit behavior and protect it from coercive nonproliferation efforts, have a higher chance of succeeding. It is hard to imagine North Korea acquiring nuclear weapons absent Soviet and then Chinese shelter. While China does not relish a nuclear-armed North Korea, and has become increasingly more disturbed by North Korean behavior over time, it has, for the most part, not been willing to use intense pressure against North Korea over this issue. China fears a North Korean regime collapse that would result in large refugee inflows and the possible stationing of U.S. troops along its border following Korean reunification.[116] The states that enjoy such shelter are few and far between, but there will undoubtedly be others. Fourth, even poor states with domestic political pathologies do not need substantial foreign assistance to successfully acquire nuclear weapons. While impoverished and/or authoritarian countries have acquired nuclear weapons before — India, Pakistan, and China, for instance — they all did so with substantially greater foreign support than North Korea received. The point of this exercise is not to dismiss any theories of nuclear proliferation, but rather to take stock of how to adjust these theories in systematic ways to account for how North Korea succeeded, while fully conceding that the proliferation process is unpredictable and probabilistic and that outliers will always exist. It is a worthwhile endeavor to see how the academic community could have better predicted North Korean nuclearization — because there will likely be other proliferators like North Korea in the future. When taken in combination with Mark Bell’s recent work showing that many of the quantitative correlates of nuclear proliferation are not reliable predictors,[117] our examination of the North Korea case suggests that we, as scholars, should be more modest about our theories’ predictive capacities.

Implications for Nonproliferation Policy

In addition to its implications for academic theory, North Korea’s acquisition of a sophisticated nuclear weapons capability has important implications for nonproliferation policy. For one thing, the North Korea case demonstrates that supply-side measures like export controls are insufficient, even against countries with poor economies. Nuclear technology is 70 years old, and North Korea has demonstrated it is possible to construct the facilities needed to produce fissile material indigenously, based on open-source information. This is true not just for the gas centrifuge, as Kemp has demonstrated,[118] but also for the plutonium path to the bomb that North Korea followed. Indeed, North Korea’s focus on domestic development of nuclear weapons, consistent with its self-reliant, or Juche philosophy, likely made it better able to adapt to technical challenges when compared to countries like Libya and Iraq, which relied more heavily on foreign imports. Moreover, the fact that North Korea indigenously developed a nuclear reactor and reprocessing facility in secret, rather than publicly constructing them under the guise of a nuclear energy program, allowed its nuclear program to make greater progress before the international community could react effectively.[119] A second policy implication is that early detection and policy intervention are crucial if nonproliferation success is to be achieved. Compared to other proliferators, North Korea was relatively successful at concealing its nuclear capabilities and intentions. Partly for this reason, strong international pressure was only mobilized in the early 1990s, when North Korea was quite close to acquiring fissile material for nuclear weapons. Indeed, one could argue that even the Agreed Framework came too late, in that North Korea may have already obtained enough plutonium for a couple nuclear devices. The failure of early detection gave policymakers little margin for error, making it easier for North Korea to succeed in its nuclear quest. Third, international sanctions have important limitations when dealing with extremely isolated countries like North Korea. Unilateral U.S. measures, or even joint measures with allies, only go so far when dealing with a country like North Korea, whose political and economic system is designed on the principle of self-reliance. This is consistent with research on nonproliferation by Etel Solingen and Nicholas Miller, whose theories predict North Korean resilience to economic and political pressure, although they focus on outcomes rather than the acquisition of nuclear weapons.[120] As an inward looking regime, Solingen correctly argues that “North Korea has defied political and economic sanctions from great powers and international institutions, allowing state agencies and industries responsible for productive and distributive functions to benefit from international closure.”[121] Relatively insulated from the international economy to begin with, North Korean leaders were willing to sacrifice the well-being of their population while the regime devoted extraordinary resources to its nuclear weapons program. Miller likewise argues that North Korea was relatively invulnerable to sanctions, although he attributes this primarily to Pyongyang’s lack of dependence on the United States, the main enforcer of the nonproliferation regime. Miller’s argument also identifies a scenario where sanctions might have worked against North Korea: namely if they had been multilateral and stronger in scope. However, U.N. nuclear sanctions were not even imposed until North Korea already acquired nuclear weapons in 2006. Moreover, despite its recent cooperation at the United Nations, China has repeatedly dragged its feet on implementing sanctions over the years, dramatically increasing its trade with North Korea between 2006 and 2014.[122] Akin to the notion of “sheltered pursuit,” sanctions face long odds of success if a proliferator is insulated from the international economy and if its primary ally refuses to implement sanctions until it’s too late and then violates the spirit of those sanctions. Fourth, if export controls and sanctions are unlikely to succeed against isolated adversaries like North Korea, and if credible threats of force have been insufficient in the past, more attention should be given to inducements and diplomacy as possible solutions. Although it is politically challenging, both internationally and domestically, to be seen as “rewarding” proliferators by offering inducements, the history of the North Korea case shows that the greatest restraints on its nuclear program were in fact achieved when Washington offered substantial inducements, i.e., the 1994 Agreed Framework. Although North Korea violated the spirit of this agreement by starting a secret enrichment program, the United States also failed to fully live up to its end of the bargain by repeatedly delaying delivery of the promised inducements. Fifth, and relatedly, the North Korea case highlights the fragility of nonproliferation bargains due to changes in the domestic and international political landscape, a dynamic that makes such bargains hard to reach in the first place. The Agreed Framework — the closest the international community came to preventing North Korea from acquiring a credible deterrent — ultimately was hampered by domestic opposition in the United States by Republicans, who opposed the agreement and later slowed its implementation.[123] This case has obvious parallels to the Iran deal, a nonproliferation bargain whose future is in jeopardy due to consistent Republican opposition, which, as in the case of North Korea, is inflamed by missile tests and extraneous bilateral issues. The fate of the Agreed Framework, along with the U.S. decisions to topple regimes in Iraq and Libya despite their WMD disarmament, raises real questions about the viability of nonproliferation deals with adversaries in the future. This leaves us, unfortunately, with an unhappy conclusion: The sort of diplomatic bargains that are needed to deal with proliferators like North Korea will be increasingly difficult to reach and sustain.

Conclusion

The fact that academic theories mostly underestimated North Korea’s chance of successfully acquiring nuclear weapons gives us an opportunity to audit our theories and adjust them based on lessons from this important case. The biggest theoretical lessons from the North Korean example are the following: 1) that our theories may overestimate the power of preventive war threats in deterring states from pursuing nuclear weapons, 2) that determined leaders, even in dysfunctional authoritarian regimes, are not always doomed to fail in this pursuit, and 3) that even poor countries can succeed at acquiring nuclear weapons based on indigenously developed technology. The policy implications are equally grim. Given enough breathing room, even a poor a state that wants nuclear weapons badly enough can acquire them, defying sanctions and threats of force — particularly if it has an ally to shelter it from a strong multilateral coalition. While offering inducements to adversary proliferators may stand a better chance of success, this is politically challenging for countries like the United States; moreover, the credibility of American diplomatic assurances is increasingly shaky. Given the various pathways to the bomb and the geopolitical fractures that proliferators can exploit, we should not assume that what has so far been a rare event — nuclear proliferation — will always continue to be so.

Nicholas L. Miller is assistant professor in the Department of Government at Dartmouth College. His book, Stopping the Bomb: The Sources and Effectiveness of U.S. Nonproliferation Policy, is forthcoming with Cornell University Press.

Vipin Narang is associate professor of political science and member of the Security Studies Program at the Massachusetts Institute of Technology.

ISSN (Print): 2576-1021 ISSN(Online): 2576-1153

Image: Wikimedia Commons

Just because nuclear war is undesirable and the probabilities of it occurring are very low is no reason not to think about it.[1]

—Secretary of Defense James Schlesinger (1974)

The Role of Nuclear Competitions Between Great Powers

What Are Great Power Military Competitions?

[T]he Anglo-German antagonism basically arose from the fact that in the half-century under scrutiny Germany grew out of its position as ‘a cluster of insignificant States under insignificant princelings’; and from the further facts that this growth gradually threatened to infringe perceived ‘British interests’, that these economic shifts increased the nervousness of British decision-makers already concerned about ‘saving the Empire’, and that they were accompanied by ideas about a German mission which could be adopted by political forces grappling with severe domestic problems.[16]

Key Features of Nuclear Competitions

Avoiding Pitfalls in Analyzing Nuclear Competitions

mutual vulnerability can be very difficult for (at least two sets of) nuclear rivals to accept in perpetuity. For a variety of reasons, it is much preferable to try to solve or at least ameliorate this strategic dilemma. Accordingly, while theories about the stability of reciprocal second-strike capabilities may be elegant, they presume a lack of agency that participants will find challenging to resign themselves to.[109]

Planning a Road Trip through Terra Incognita

Plans are worthless, but planning is everything. There is a very great distinction because when you are planning for an emergency you must start with this one thing: the very definition of ‘emergency’ is that it is unexpected, therefore it is not going to happen the way you are planning. So, the first thing you do is to take all the plans off the top shelf and throw them out the window and start once more. But if you haven't been planning you can't start to work, intelligently at least. That is the reason it is so important to plan, to keep yourselves steeped in the character of the problem that you may one day be called upon to solve—or to help to solve.[131]

Nuclear Strategy

A Primer on Analyzing Nuclear Competitions

How to Think About Nuclear Crises

Rethinking the Bomb: Nuclear Weapons and American Grand Strategy

Marching Toward a U.S.-North Korea Summit: The Historical Case for Optimism, Pessimism, and Caution

North Korea Defied the Theoretical Odds: What Can We Learn from its Successful Nuclearization?

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The Role of Nuclear Competitions Between Great Powers

What Are Great Power Military Competitions?

Key Features of Nuclear Competitions

Avoiding Pitfalls in Analyzing Nuclear Competitions

Planning a Road Trip through Terra Incognita

Our Understanding Of Nuclear Crises

Models of Nuclear Crises

Historical Crises: The Cuban Missile Crisis and the Kargil War

Contemporary and Future Crises: Doklam and U.S.-North Korea

Conclusion

I. The Wrong Revolution?

II. Missing Histories

III. A Loss for Words?

IV. Worse Before It Gets Better

V. Resisting the Revolution, or Revolution à la carte

Conclusion

Pessimism: Denuclearization Is Harder Now Than During Past Efforts

Caution: New Leaders on Both Sides

Optimism: Allies, Peace Regime, and Learning

Conclusion

A Brief History of North Korea’s Nuclear Weapons Program

How Did Academic Theories Perform?

Implications for Nonproliferation Policy

Conclusion

The Role of Nuclear Competitions Between Great Powers

What Are Great Power Military Competitions?

Key Features of Nuclear Competitions

Avoiding Pitfalls in Analyzing Nuclear Competitions

Planning a Road Trip through Terra Incognita