In April 2025, I found myself in a quiet corner of the UK Defense Academy in Shrivenham, trading notes with a senior Royal Air Force (RAF) officer about what a second Trump presidency might mean for the UK, NATO, and the wider US-led alliance system. “Look,” he said, “it is mostly politics, which might change every four or eight years. What endures are the data links our aircraft share, bases, intelligence, and logistical networks. We depend on the Americans more, but those dependencies run both ways. They can’t be unwound easily.”
He was right in important aspects. The electromagnetic, logistical, and command-and-control sinews that have bound allies together since the beginning of the Cold War are not easily severed. Yet military technology trends do not stop for electoral cycles, and the United States is rapidly losing its margin of military dominance in the Indo-Pacific. Not only has the quality gap between US and Chinese weapons systems narrowed significantly, but China’s numerical advantage has also become evident. The People’s Liberation Army Navy (PLAN) is now the world’s largest navy, possessing almost one-third more battle-force ships than the US Navy, with many of its newer vessels comparable in capability to their American counterparts.1 The People’s Liberation Army Air Force (PLAAF) is on track to become the world’s largest air force, fielding around a hundred fifth-generation aircraft annually, along with a larger number of fourth-generation fighters.2 Meanwhile, the People’s Liberation Army Rocket Force (PLARF) has thousands of conventionally armed ballistic and cruise missiles, generating enough anti-ship firepower to target every US surface combatant in the South China Sea and overwhelm their missile defenses.3 At the same time, China is acquiring advanced weapons systems and equipment at a rate five to six times faster than the United States.4
When I mentioned these figures, the RAF officer paused before offering a more sobering conclusion: “If allies see clearly that US military dominance is gone, the political mood in Washington won’t matter. Every capital will re-price its risk.” Namely, visible material shifts may exert more durable strategic effects than any single administration’s policy orientation. Erosion of US military power will inevitably force even the most committed allies to reassess the credibility of American security guarantees.
This recognition sets the stage for the argument developed here. The United States’ armed forces confront a complex set of problems: depleted arsenals, a diminished defense industrial base, and supply chains that run through China. These weaknesses have been highlighted in official audits, Senate hearings, war-game after-action reports, and an expanding body of scholarship.
Strategic imagination in allied capitals, however, has been slow to connect these warning signs to the possibility that US military primacy in its principal theater may soon be—or already is—over. Although allies were aware of the difficulties the United States faced in sustaining military aid to Ukraine, they largely continue to associate American power with images of supercarriers, global GPS dominance, and enduring logistical supremacy. Accordingly, the facade of US military power is largely intact among allies. Subconsciously, strong confidence persists that Washington will maintain its edge, as it has always done.
This gap between material reality and psychological perception closely mirrors Britain’s situation before the Suez Crisis in 1956. Although economic weakness and strategic overextension were already evident by the early 1950s, the failed intervention made Britain’s diminished great-power status clear. When the United States refused to support its closest ally and instead forced London into a humiliating withdrawal, it became clear that British military power was no longer sufficient to sustain imperial ambitions on its own.
Niall Ferguson has suggested that a failed or foregone US defense of Taiwan could constitute America’s “Suez moment,” a point at which strategic reality and global perceptions of US military power brutally converge.5 While Ferguson emphasizes the psychological rupture that such a moment might induce, structural implications also merit close examination. Philip Zelikow also draws on the Suez Crisis to caution that strategic ruptures often emerge not from grand designs, but from opportunism and miscalculation within allied governments. He highlights how the Anglo-French-Israeli intervention at Suez blindsided Washington, demonstrating how fragile alliance coordination can become in volatile periods. Zelikow’s warning suggests that the United States must prepare not only for adversarial moves, but also for the risk that its own alliances might fray under stress.6
“While a decisive US setback in the Indo-Pacific is by no means inevitable, its likelihood has grown.”
This article asks: How would the US alliance system respond to a major credibility shock in the Indo-Pacific, such as a failed or foregone defense of Taiwan? Even if such a shock never comes, analyzing its mechanics can illuminate the underlying forces that already shape alliance cohesion and help allies minimize gradual erosion.
While a decisive US setback in the Indo-Pacific is by no means inevitable, its likelihood has grown. Rapid Chinese military modernization, the geographic asymmetries of Indo-Pacific contingencies, and an increasingly level regional force balance now place the United States closer to military parity with a great power in the Indo-Pacific than at any time since World War II. These trends, and the growing prospect that the balance may soon tilt in Beijing’s favor, elevate a potential American “Suez moment” from a theoretical concern to a scenario warranting serious analytical attention. Subsequent sections examine the evolving military dynamics and show how rising Chinese capabilities, coupled with different alliance dynamics, continue to widen the margin of uncertainty for US success in the Indo-Pacific.
Accordingly, this article combines two analytical lenses: the post-Suez British experience of alliance hollowing, and a five-factor theory of defense cooperation developed through comparative research,7 grounded in eight years of experience in defense planning at the Hungarian Ministry of Defense, including NATO capability development and minilateral cooperation.
I find that a visible US military setback in the Indo-Pacific—a potential American Suez moment—would significantly weaken US leadership within its alliance system by exposing critical capability shortfalls. Although a Suez moment could serve as a signal that provides information about US capabilities, allowing each actor to update their beliefs,8 I focus on the alliance-level mechanisms through which shocks reshape defense cooperation. While such a shock would deeply challenge American credibility, that scenario would not necessarily lead to the immediate collapse of the alliance system. Structural factors such as enduring security communities and established habits of cooperation, coupled with situational factors like a conducive political environment and effective leadership, would likely mitigate the initial damage and uphold near-term stability. Nevertheless, the long-term viability and strategic relevance of America’s alliances would depend on whether the United States and its partners credibly address the underlying capability deficits. If substantial corrective actions do not follow a crisis moment, alliances might endure formally, but are likely to become increasingly transactional and strategically hollow, gradually undermining decades of US global leadership.
Dynamics of Defense Cooperation
Defense cooperation is understood here as any arrangement in which two or more states work together to enhance military capabilities. This cooperation can happen, for instance, through joint training and exercises, personnel exchanges, shared doctrine, coordinated equipment procurement, the establishment of combined headquarters, or the formation of multinational units.9 I seek to explain the potential erosion of existing defense cooperation arrangements, not their initial treaty-signing.
A rich body of scholarship examines how and when alliances weaken or are abrogated,10 most of which emphasizes that defense cooperation is rarely driven by a single factor.11 On the demand side, Stephen Walt’s classic work on alliance politics highlights shifting threat perceptions, the credibility of commitments, domestic political change, and the presence (or absence) of hegemonic leadership, shared identities, and security communities as key forces that shape when alliances deepen or unravel.12 On the supply side, Brandon Kinne demonstrates that even when states want to cooperate, information problems can stall agreement; governments hesitate to commit unless they trust prospective partners and understand the design costs of a new defense cooperation. Network dynamics solve this problem, as preferential attachment (smaller states gravitating toward established “hub” partners) and triadic closure (friends of friends linking up) create self-reinforcing pathways.13
Differentiating between situational and structural factors offers a useful analytical lens to anticipate how cooperation might erode when foundational conditions change. Viewed through this lens, defense cooperation follows a distinct pattern. Most of the time, military cooperation among states remains relatively static, with activity levels fluctuating only modestly. When a critical mass of enabling situational and structural factors align, however, cooperation can deepen rapidly over a short period of time.14 If one or two of these factors subsequently weaken or disappear, the momentum of cooperation typically slows, though often stabilizing at a level higher than that which preceded the catalyzing factors. When multiple enabling conditions are seriously undermined, however, defense cooperation itself begins to unravel.
This pattern reflects the interaction between two categories of forces, shown in table 1. Situational factors—often fast-moving and contingent—function as catalysts, triggering windows of opportunity for deeper cooperation. Structural factors, by contrast, evolve more gradually and provide the enduring foundations that sustain cooperative defense ties. Situational dynamics create openings, but without resilient structural foundations, defense cooperation can erode.
Table 1. Relevant factors for evolution of security and defense cooperation
The first situational factor is a conducive political milieu. This supportive environment may arise from domestic political shifts, international events, or a combination of both. Importantly, a conducive political milieu does not create the same incentives everywhere; different states may find cooperation attractive for very different reasons. For example, the 2010 Franco-British Lancaster House Treaties, a landmark bilateral defense agreement, emerged from different political motives: While the French president aimed to assert European defense leadership, the UK government intended to demonstrate domestically that close European cooperation was possible outside deeper EU integration.15 More recently, Russia’s invasion of Ukraine created a conducive political milieu that catalyzed and accelerated a wide range of defense cooperation—including the NATO accession of Sweden and Finland, two long-standing non-aligned countries16—as governments reassessed their security posture and sought to reinforce collective deterrence. A favorable political milieu does not guarantee success, but without it, collaborative efforts struggle to gain traction.
Second, leadership and interpersonal chemistry often determine whether defense cooperation advances. Leaders who share common values and recognize similarities in outlook tend to work together more easily. For instance, political leaders who value alliances and whose personalities favor consensus-building are more likely to catalyze military cooperation. Recent experience offers a sharp contrast. During the Biden administration, US-led defense cooperation flourished both in Europe and the Indo-Pacific, reflecting an emphasis on alliance cohesion and shared strategic objectives.17 By contrast, Donald Trump’s confrontational rhetoric, transactional approach, and skepticism toward alliances have tended to undermine defense cooperation even among long-standing partners.
While these two situational factors generate initial windows of opportunity for cooperation, three structural factors provide long-term foundations for defense cooperation. These underlying conditions evolve slowly and help stabilize relations between states. When seriously undermined, however, they can destabilize even the most established alliances.
First, the existence of a security community provides the bedrock for enduring defense cooperation. In a security community, member states not only resolve disputes peacefully but also share a common understanding of security issues and a sense of collective identity.18 This “implies that joint gains increase when states are politically similar, aligned in their foreign-policy preferences, or otherwise strategically valuable.”19 The US-led Western alliance system has long embodied this dynamic, building on decades of cooperation and integration through NATO in the transatlantic area and through numerous bilateral and minilateral arrangements in the Indo-Pacific.
“Militaries find it much easier and effective to cooperate with partners they have worked with before.”
Situational factors, however, can stress these foundations. Statements in recent years by President Trump—such as proposing to “take” Greenland from Denmark (a NATO ally), suggesting that Canada (another NATO ally) become the fifty-first US state, and disregarding European interests during peace negotiations over Ukraine while showing partiality toward Russia20—have strained perceptions of shared identity and weakened the sense of belonging to a common security community.
The second structural factor—a history of previous defense cooperation—matters enormously. Militaries find it much easier and effective to cooperate with partners they have worked with before. Prior experience reduces transaction costs, improves interoperability, and establishes a form of path dependence that can endure even after political ties weaken. Even in cases where a security community is weak or nonexistent, long-standing military cooperation can function as a stabilizing anchor. A striking contemporary example is the rapid rekindling of military cooperation between Russia and North Korea. Drawing on Cold War–era familiarity with compatible standards, munitions, and doctrines, Pyongyang has supplied Russia with significant quantities of artillery shells, ballistic missiles, and other forms of military aid to support its war effort in Ukraine.21 This renewed partnership demonstrates how latent military ties based on previous cooperation can be reactivated quickly when other factors align, even in the absence of deep trust or shared political values.
The third structural factor involves perceived resource shortfalls, which often motivate states to pursue defense cooperation. States may lack the financial means, technical capabilities, or political legitimacy to secure their objectives independently. In Europe, enduring budgetary constraints have long driven many states to pool resources and seek joint solutions to maintain operational effectiveness. In Asia, South Korea’s recent deeper engagement with NATO partly reflects a perceived need to compensate for limited integration into Western security structures. Historically, the United States has also sought allied participation in conflicts such as Korea, Vietnam, Iraq, and Afghanistan—not only to reduce operational burden but also to bolster the political legitimacy of its interventions.
Even where political trust is limited, perceived resource needs can sustain practical cooperation. For instance, while China and North Korea maintain a formal mutual defense agreement, their bilateral relationship is characterized more by mistrust than by genuine partnership. For Beijing, the Democratic People’s Republic of Korea remains strategically relevant in preventing US dominance of the Korean Peninsula. For Pyongyang, economic reliance on Chinese trade and investment provides an essential lifeline. In such cases, cooperation persists not because of shared values or political affinity, but because both parties recognize that access to critical resources—strategic depth for China and economic survival for North Korea22—remains vital to their respective interests.
This final structural factor, perceived resource shortfalls, is particularly relevant within the US-led alliance system, in which most allies rely on American support and in which allied capability shortfalls—whether in military strength, technological capacity, or strategic reach—are filled by the US military. As the RAF officer noted, allies recognize their dependencies, but have long trusted in US superiority to sustain them. A Suez moment—a clear and public failure that exposes US military weakness—could fundamentally undermine this belief, casting doubt on the United States’ ability to compensate for allied deficiencies. Unlike political leadership, which can shift with electoral cycles, or the sense of security community among allies, which can be partially repaired under more alliance-friendly leadership, the perception of resource inadequacy is harder to reverse once exposed. In a world in which shifts in allied military capabilities increase the risk of alliance weakening,23 a Suez-type shock would damage the alliance system at a structural level, jeopardizing the foundation of material dependence that has sustained US leadership for decades.
The five factors interact hierarchically. A security community provides the umbrella of trust, but beneath it, the dynamics of the other four factors can strengthen or weaken the security community. The absence of a security community does not preclude ongoing or effective defense cooperation. The other two structural factors can still provide a foundation for cooperation, but under such conditions, cooperation tends to become more transactional and less stable.
A Suez moment would not automatically result in the complete disintegration of the US alliance system. Its impact would depend on how structural and situational forces interact. Table 2 highlights that when both situational factors align with all three structural factors, partnerships either form or deepen quickly.24
Table 2. Relationship between the five factors of defense cooperation
paper; partners seek alternatives |
Note: Structural factors include (1) security community, (2) prior cooperation, and (3) perceived resource shortfalls. Situational factors include (1) conducive political milieu, and (2) leadership and chemistry.
If the structural base remains intact but one or both situational factors fade, the relationship settles into “Maintenance,” steady yet no longer growing. If one structural factor is lost, then the best-case outcome is “Adaptation,” where at least one situational factor still pushes cooperation forward, but capacity and ambition contract. If only one structural factor remains, the arrangement enters “Hollowing,” and interaction becomes largely ceremonial, while members look elsewhere for meaningful security cooperation. No single structural factor is sufficient on its own; at least two of the three must remain intact for defense cooperation to persist. In short, situational factors dictate the pace, while the structural factors set the ceiling or floor for defense cooperation.
US Military Weaknesses and the Shifting Military Balance in the Indo-Pacific
How do current US military weaknesses threaten the structural resource-gap factor, thereby creating the conditions for potential alliance deterioration? In April 2025, during a closed-door conversation with a former senior national security official from a US treaty ally in Northeast Asia, I encountered a telling contradiction. The official was candid about US industrial limits: “The United States simply cannot outbuild China anymore. Washington is going to need help from both South Korea and Japan.” He was referring to the enormous gap between Chinese and American ship production, a gap so vast that even the world’s most advanced navy cannot bridge it alone.
Yet, less than an hour later, when I asked whether he believed the military balance in the Indo-Pacific was now tilting in China’s favor, his tone shifted. “No,” he said firmly. “The US Navy will maintain maritime supremacy. It has more tonnage, more reach, more experience.”
This type of cognitive dissonance is not uncommon. Across numerous conversations with allied officials and military officers, I have encountered a similar pattern: recognition of specific US vulnerabilities (for example, aging shipyards, depleted stockpiles, and declining repair capacity) paired with an unshaken confidence in US military primacy. This contradiction reflects more than just institutional optimism, it reveals a deeper strategic inertia. For many allies, American dominance is not just expected, it is axiomatic, because it has existed for decades.
A growing body of scholarship increasingly challenges that premise. Allied assessments continue to underestimate China’s actual defense spending. Although Beijing’s official 2024 defense budget is roughly $230 billion, independent estimates suggest that the true figure could exceed $700 billion when adjusted for purchasing power, hidden expenditures, and lower labor costs.25 Even conservative estimates place it around $470 billion, double the official figure.26 And unlike the globally dispersed US defense budget, China’s spending is heavily concentrated on building regional advantage in the Indo-Pacific.
“Together, these developments suggest that the era of unquestioned US military supremacy may be coming to an end.”
Structural vulnerabilities within the US force posture and shifting geopolitics are compounding fiscal and military-industrial issues. Analysts have long warned of a growing mismatch between America’s global military obligations and its force structure.27 The abandonment of the “two-war” sizing standard in favor of a one-war model, which took place in 2018, reflects the quiet admission that the US could not credibly handle a second major contingency while, for example, engaged in combat operations in the Indo-Pacific.28 Operationally, readiness shortfalls and dwindling stocks of precision munitions have raised concerns across services.29 Meanwhile, the erosion of the US defense-industrial base—particularly in shipbuilding, missile production, and depot maintenance—poses significant challenges to force reconstitution in the event of any protracted conflict.30
Together, these developments suggest that the era of unquestioned US military supremacy may be coming to an end. Although this view has yet to fully register in many allied capitals, the underlying trends are persistent and entrenched. China has emerged not just as a pacing threat but, in many respects, as a peer military power in its own region. In quantitative terms, it fields a significantly larger naval force: 395 battle-force ships compared to about 295 for the US Navy as of 2025.31 This figure does not include China’s paramilitary fleet, which includes heavily armed and up-armored Coast Guard and maritime militia vessels capable of operating as wartime auxiliaries.32
China’s land-based missile forces further tilt the regional balance. According to the latest Pentagon report on Chinese military capabilities, the PLARF possesses approximately 3,500 ballistic and cruise missiles,33 supplemented by advanced precision-strike systems fielded by other services, all designed to overwhelm US naval assets and forward bases in the event of conflict. While the effectiveness of these systems against moving maritime targets remains unproven, their potential has already prompted significant adjustments in US operational doctrine in the Indo-Pacific.34 Additionally, China is now outproducing the United States by a wide margin in production of theater-range missiles and precision-guided munitions.35 War games simulating a Taiwan contingency increasingly yield inconclusive results: Neither side can expect a swift or low-cost victory, suggesting the emergence of a new form of strategic parity. Furthermore, although the reason for China’s rapid nuclear buildup is interpreted by analysts differently—ranging from a response to US missile defenses to an assertion of great-power status or a shield for conventional assertiveness36—it nonetheless reinforces this emerging parity.
Meanwhile, China’s naval shipbuilding is unrivaled. Leveraging the world’s largest commercial shipbuilding industry, now producing over half of global output, China enjoys a roughly 230-to-1 advantage in naval production capacity over the United States.37 This industrial base will enable Beijing to quickly expand, sustain, and replace naval forces at a scale Washington cannot hope to match. At the current trajectory, China is projected to match the US Navy in total deployed firepower by 2027, and surpass it thereafter.38
Nonetheless, qualitative US advantages remain. The US Navy operates eleven nuclear-powered aircraft carriers to China’s three, and its carrier aviation includes more advanced fighters like the F-35C. US nuclear attack submarines (SSNs) significantly outmatch their Chinese counterparts in range, stealth, and lethality. American surface combatants generally have more firepower per hull, and the United States benefits from a global network of bases, replenishment ships, and allied facilities that provide strategic reach.
But this global posture is also a constraint. In a high-end conflict over Taiwan or in the South China Sea, China enjoys the advantage of regional concentration. Unlike the American military, the PLA does not need to allocate forces across multiple theaters. It can mass firepower locally, supported by integrated air defenses, long-range rocket forces, and a mature anti-access / area denial (A2/AD) architecture.
The US military has begun to adapt. It is dispersing forces, hardening airfields, and investing in survivability across its Indo-Pacific posture. Some allied observers have taken notice. As one Australian analyst noted: “The emphasis on survival is correct because America is not building a presence in Asia that is designed to win a war against China. Its strategy is designed merely to survive one.”39
“What has shifted, however, and now demands careful strategic reflection, is that a conflict in which China avoids defeat, or secures a clear regional advantage, has become a credible and plausible scenario.”
This growing asymmetry is captured with striking clarity in a paper by Malcolm Kyeyune40 that reportedly “went viral” among faculty and students at the US Naval Academy. Kyeyune argues that the very premise of a future kinetic conflict with China, as currently imagined by many in Washington, would be incoherent to mid-twentieth-century military planners, and for good reason. The Pentagon itself estimates China’s naval shipbuilding output to be 230 times greater than that of the United States.
Kyeyune places this in historical perspective: Imperial Japan’s shipbuilding disadvantage relative to the US in the 1940s, considered decisive then, was around ten to one.41 That disparity shaped Japanese war planning. Japanese doctrine, despite its other flaws, did acknowledge industrial inferiority and sought to offset it through geography, exploiting the vastness of the Pacific to strain US logistics and force one or more decisive engagements on favorable terms. That strategy ultimately failed, but it was grounded in a clear understanding of Japan’s limitations.
Today, the strategic roles are reversed. It is the United States, not the regional power, that faces the larger industrial deficit—this time, without the benefit of proximity or regional geography. No Japanese planner ever contemplated victory off the coast of California, yet this is the type of asymmetry the US may now be forced to confront. Kyeyune argues that believing that tactical brilliance or legacy qualitative advantages alone can overcome this imbalance reflects a kind of strategic magical thinking.42 Without a course correction, industrial revitalization, greater allied burden-sharing, and operational adaptation, the United States risks entering a future conflict under conditions more lopsided in many aspects than those that proved fatal to Imperial Japan.
The vulnerabilities outlined above do not imply that war between the United States and China is inevitable, nor that American defeat is predetermined. The US military still possesses formidable strengths, and any confrontation will impose immense risks and costs on both sides. What has shifted, however, and now demands careful strategic reflection, is that a conflict in which China avoids defeat, or secures a clear regional advantage, has become a credible and plausible scenario.43 The likelihood of an Indo‑Pacific war whose outcome is uncertain, or in which the United States fails to achieve its aims, has risen significantly.44 What, then, would be the strategic and political implications of a visible American military setback—a contemporary Suez moment—for the US-led alliance and partnership system?
The Relevance of the Suez Analogy
In late 1956, Britain, alongside France and Israel, launched a short-lived invasion of Egypt to reverse President Gamal Abdel Nasser’s nationalization of the Suez Canal. The operation succeeded tactically, but collapsed under intense diplomatic and financial pressure, most notably from the United States. Within days, President Eisenhower threatened oil and currency sanctions, and as a result, London accepted a UN‑brokered ceasefire and withdrew all forces. Britain was not defeated on the battlefield, but Suez became a moment of national humiliation that laid bare the limits of British power. London discovered that it could no longer pursue its strategic ambitions without American consent, and allies and adversaries recalibrated their views of British power accordingly.45
The international and domestic repercussions were swift and far‑reaching. Britain’s closest Commonwealth partners distanced themselves, Pakistan threatened to withdraw from the Commonwealth, and only Australia offered vocal support. The UK’s “special relationship” with Washington suffered severe strain, while the Soviet Union seized the moment to champion anti-imperialism in the Arab world. Domestically, public protests, cabinet resignations, and collapsing confidence forced Prime Minister Anthony Eden from office. Though the crisis lasted barely forty‑eight hours, its strategic consequences endured: Britain’s transition from global power to second‑tier actor became unmistakable. Suez showed how quickly perceptions of strength can collapse among allies, and how visible material weakness can trigger a crisis of confidence among partners and embolden rivals. Margaret Thatcher later reflected that, before Suez, the UK exaggerated its power, while the crisis and its aftermath exaggerated UK impotence.46
The aftershock of the Suez Crisis confirming that Britain could no longer sustain a globe-spanning empire by force accelerated decolonization. London granted independence to dozens of colonies on a rushed timetable and, by 1968, started to withdraw most of its forces from “East of Suez.”47 The retreat reconfigured, rather than completely severing, Britain’s military ties. Former imperial garrisons became partner bases, and the connective tissue of shared doctrine, rank structure, and professional military education kept Britain embedded in armed forces it had once commanded. Even today at the UK Defense Academy, Commonwealth officers fiercely compete for places at British staff colleges, and employ British habits, legal codes, and operational vocabulary. Competence and habit thus preserved London’s relevance even as its power shrank.
Institutionally, Britain remained consequential but accepted a reduced role inside both the Commonwealth and NATO. It retained permanent facilities or access rights in Brunei, Cyprus, Kenya, Singapore, and Canada, among others, and in the 2010s and 2020s added new footholds in Bahrain, Oman, Qatar,48 Norway, and Australia. The UK also constructed a web of bilateral and minilateral frameworks: It remains a party to the Five Power Defense Arrangements with Australia, Malaysia, New Zealand, and Singapore (1971–present);49 it leads the ten-nation Northern European Joint Expeditionary Force, activated in 2014 for rapid deployments from the High North to the Baltic;50 and it is a founding member of AUKUS (2021),51 the technology‑sharing pact that plans to give Australia nuclear‑powered submarines and knit UK research into US and Australian advances in undersea, artificial intelligence, cyber, quantum, hypersonic, and electronic warfare domains.
In short, Suez ended Britain’s era of strategic primacy, but not its relevance. By leveraging legacy networks, niche capabilities, and flexible partnerships, London transformed imperial overstretch into a lighter, still influential global posture. That record suggests that after a “Suez moment,” the United States could likewise preserve the cooperative sinews that allies still find useful, but its role in global politics would nonetheless change.
Britain’s continued relevance after Suez can be framed in terms of the five factors outlined earlier,52 and particularly by the persistence of three structural factors on a diminished level:
- the legacy of prior cooperation—shared doctrine, officer exchanges, and a certain level of interoperability—lowered the cost of continued cooperation and made London an attractive default partner;
- the United Kingdom could still deliver niche capability offsets that filled allies’ resource gaps, such as expeditionary forces, specialized intelligence, technological expertise and professional military education; and
- membership in the Commonwealth, while of declining relevance, maintained (and still maintains) a residual sense of community. Although uneven, this institutional connection still carries operational consequences: Commonwealth citizens remain eligible to serve in the UK armed forces.
Important distinctions temper—but do not invalidate—the Suez analogy and its lessons for today. Postwar Britain was already a middling economy with limited capacity and few allies willing to underwrite its ambitions. The United States today, by contrast, commands the world’s largest GDP, fields unmatched global lift and C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance) capabilities, and anchors a sprawling lattice of treaty allies across Europe and Asia. Any confrontation with China would be a peer-level fight, not an imperial police action.
The parallel that Suez directs us to look at, however, is psychological rather than mechanical. As in 1956, the central power in the alliance system—then Britain, now the United States—functions as the guarantor of security and the keystone of collective credibility. Should a high‑visibility setback in the Indo‑Pacific suddenly reveal acute shortfalls in US military capacity, allied confidence could unravel with the same speed and severity that followed Suez. This potential rupture in perception, rather than an exact replication of events, makes Britain’s experience a relevant stress test for America’s position today.
Stress‑Testing a US “Suez Moment” in the Indo‑Pacific
A Suez moment for the US need not involve a catastrophic defeat or even the outbreak of a full-scale conventional war. It could arise from a limited skirmish in, for example, the South China Sea, or from a series of inconclusive engagements that cumulatively expose a new strategic reality: that the United States no longer enjoys uncontested military primacy in the Indo-Pacific. I argue that such an event could generate a perceptual rupture, compelling allies to reassess long-standing assumptions about American power and adapt their behavior in response.
Such a moment could strike at the heart of the US-led alliance system by undermining one of the most critical structural factors in the five-factor theory of defense cooperation: perceived resource gaps.53 For decades, American allies have relied on the assumption that their own shortfalls in military capacity could be offset by American strength. A Suez-like event would call that assumption into question. And unlike the original Suez crisis, where the United States could fill the vacuum left by a declining Britain, no other benign hegemon is capable of assuming a similar role today.
In such a context, the assurance literature suggests two broad patterns of allied responses.54 Dissatisfied allies tend to either pursue self-reliance (including, in extreme cases, nuclear options), or they seek to diversify their strategic risk through steps that could include deeper ties with each other, hedging strategies toward regional powers like China or Russia, or a hybrid approach.
“For decades, American allies have relied on the assumption that their own shortfalls in military capacity could be offset by American strength.”
Two scenarios illuminate how the US alliance system could evolve following such a moment. Both assume a loss of US primacy and the resulting collapse of the perceived resource-gap assurance that has long underpinned allied confidence. These scenarios hold constant another structural factor: prior defense cooperation, which encompasses interoperability, shared platforms, and institutional memory built over decades, assuming these remain intact. Where the scenarios diverge is in how the three other variables evolve: the strength of the security community (structural), the broader political milieu (situational), and the quality of political leadership (situational). These factors shape whether a visible setback leads to alliance hollowing or to adaptation.
Both scenarios hold prior defense cooperation constant because American military cooperation with allies since 1945 has been uniquely durable. The United States and its treaty allies, in NATO and the Indo-Pacific, have cooperated militarily since the late 1940s and early 1950s. Decades of integrated planning, joint exercises, shared procurement, logistics interoperability, and intelligence coordination have created deeply institutionalized defense relationships that go far beyond alignment. In some cases, the United States leads integrated command structures, such as in NATO and the US–Republic of Korea Combined Forces Command. Technology dependence, doctrinal convergence, standardization processes, and common strategic vocabulary have produced a form of operational intimacy unmatched in the modern alliance landscape.
Even in the UK’s post-Suez trajectory, as British power and influence sharply declined, Britain has retained the ability to leverage its legacy defense ties for decades, drawing on relationships built on institutional habit, institutional memory, and compatible systems. If such ties endured between Britain and its former colonies, despite their asymmetric and often colonial character, the ties are more likely to persist between the United States and its treaty allies, whose relationships are based on sovereign consent, institutional equality, and far deeper technical integration. In fact, historical precedent suggests that even coercive alliance structures can leave a long tail of influence; for example, many former Warsaw Pact members retained Soviet equipment, organizational habits, and doctrinal mindset well into the 2010s, despite joining NATO and actively reforming their forces. The transition to a US-led defense culture in these countries has taken decades, even under conditions of political and voluntary willingness to integrate.55 In the event of a US Suez moment, no ready-made alternative alliance system would exist to absorb or redirect these ties. Accordingly, prior defense cooperation constitutes the most resilient factor available to the United States, regardless of whether the alliance system begins to hollow or starts to adapt.
Scenario A: A Hollowing Alliance
The first scenario considers a future in which alliance structures—NATO in the transatlantic region and the hub-and-spokes system in the Indo-Pacific—remain formally intact, but gradually hollow, becoming institutional shells with little meaningful defense cooperation. This outcome becomes likely if at least two structural factors deteriorate significantly and situational factors fail to generate opportunities for renewed collaboration or reinforced alliance cohesion. Because prior defense cooperation is expected to remain resilient, the other two structural factors—perceptions of the US ability to fill allies’ resource gaps and the continued strength or erosion of the security community—will be key to determining the future of American defense cooperation in Asia.
Whether allies continue to regard the United States as a credible guarantor will depend heavily on how they interpret its military performance. If a US Suez moment takes the form of a full-scale conventional (non-nuclear) war with China, one in which the United States is decisively defeated and suffers the loss of significant naval, air, and logistical assets, then allied confidence in Washington’s ability to provide security will likely collapse. Given current limitations in US industrial capacity, Washington may prove unable to reconstitute its military advantage at pace, thereby losing even its niche or specialized capabilities that might otherwise justify continued alliance relevance.
Even a costly victory could prove disastrous. As Jonathan D. Caverley warns: “If Taiwan remains free but much of the US Seventh Fleet lies on the ocean floor, Washington could emerge worse off operationally than if China had taken the island while the fleet stayed intact.”56 In such a scenario, the US might become so strategically overstretched or regionally preoccupied that its relevance in multiple theaters becomes fundamentally diminished. The incentive for cooperation with the United States would erode sharply, and alliance mechanisms would lose operational substance.
Diminished military capabilities do not automatically signal the end of cooperation if the security community remains coherent. Despite declining defense spending and military strength over the past three decades, European countries have expanded their cooperation, precisely because they must rely more on one another. This dynamic only works, however, in the context of a strong security community: a shared identity and similar understanding of security issues and priorities.57 If that communal sense begins to erode, a foundation of defense cooperation collapses. The dense network of bilateral and minilateral initiatives seen across Europe today is the product of decades of trust, institutional familiarity, and shared values. Thus, if the United States were to suffer a visible military setback while simultaneously diverging in cultural and normative alignment from its allies, alliance hollowing would accelerate dramatically.
Situational factors could, in theory, partially reinvigorate the security community,58 especially through leaders who value alliances or via a political milieu that encourages renewed integration. Recent developments however, such as the second Trump administration’s actions toward Europe and other security partners,59 have produced adverse situational dynamics. Not only has US leadership become more transactional, but the political atmosphere surrounding alliances has grown more skeptical and inward-looking. If these trends persist, the security community could be permanently undermined, and—if coupled with declining military utility—is likely to render US-led defense cooperation increasingly hollow.
Under such conditions, the outward appearance of alliances would likely persist, but their relevance would fade. Bilateral agreements, multilateral forums, and alliance institutions would continue to function, on paper. A useful analogy is the Organization for Security and Co-Operation in Europe (OSCE). Once a meaningful forum for arms control and political dialogue between Russia and the West, the OSCE has experienced “unabated decline”60 since the mid-1990s: still operational but largely ceremonial; still meeting, but increasingly marginal. Scenario A depicts a similar US alliance system: a “zombie alliance” that is not formally dead, but also no longer fully alive.
Scenario B: Adaptation (The “UK Post-Suez” Model)
In a more positive—and arguably more probable—scenario, only one of the structural factors, rather than two, is significantly degraded, while the others remain intact. Under such conditions, the United States would likely retain the ability to manage its alliance system, but the nature of cooperation would evolve. As with Britain after the Suez Crisis, the US could continue to play a central role in defense partnerships, but its dominance would recede, giving way to a more distributed and negotiated model of cooperation.
At the structural level, prior defense cooperation would remain a critical source of US leverage. The accumulated legacy of joint operations, shared platforms, interoperability, and integrated command structures would continue to generate strategic value, serving as both institutional memory and practical utility.61 Even in the aftermath of a visible setback, this legacy capital would enable Washington to reinvigorate partnerships, particularly where allies continue to depend on US technologies, logistics, and intelligence support.
The most uncertain variable in this scenario is the perceived resource gap. If a US Suez moment does not result from a devastating conventional war—one in which the US loses vast amounts of military capability it cannot reconstitute—but rather from some kind of strategic non-intervention (for example, Washington choosing not to engage in a Taiwan contingency), or a limited skirmish in the South China Sea that exposes specific vulnerabilities, the US may still retain enough capability to reassure its allies. Alternatively, if the US loses a conflict but is able to preserve its niche or specialized capabilities (for example, nuclear submarines, long-range strike, and intelligence, surveillance, and reconnaissance), or can regenerate strength quickly, many allies will continue to see Washington as a necessary security partner who can backstop their weaknesses (just not as much as before). Mirroring the UK post-Suez, the US might then gradually reduce its global military footprint, but retain enough capability to support select partners and exchange security services for strategic access, defense markets, or political influence. The result would be a less dominant but still relevant international role.
Conversely, if the security community remains strong, even a significantly declining US military capacity would not necessarily sever allied cooperation. A persistent sense of “we-ness,” grounded in decades of common values, shared institutions, and mutual trust, can sustain alliances through periods of material decline. The British Commonwealth helps London to continue to enjoy defense goodwill and access across many member states. These symbolic and institutional bonds retain diplomatic and operational value, especially when combined with preexisting defense cooperation and favorable situational dynamics.
Situational factors may also provide new openings for renewed US leadership. Even if a second Trump administration undermines the sense of community and allied cohesion, this atmosphere may prove temporary. A future, more alliance-friendly US president could reinvigorate cooperation (although not necessarily repair it entirely), particularly if accompanied by a conducive political milieu. Brexit, for example, deeply strained London’s ties with European allies, but its subsequent unwavering support for Ukraine during Russia’s full-scale invasion helped repair trust.62 When political leadership in the UK then shifted to a more pro-European stance, cooperation deepened further, accelerated by shared concerns about US strategic reliability. This development suggests that political will and external events can combine to revive alliance momentum, even after disruptive episodes.
This second scenario does not promise preservation of American dominance; rather, it offers a pathway to continued relevance. A “post-Suez” United States could remain first among equals, leveraging its enduring assets to maintain a cohesive, if less hierarchical, alliance system.
Conclusion
The United States may be approaching a strategic inflection point—a “Suez moment” where the gap between material capability and perceived dominance becomes unsustainably wide. Such a rupture need not emerge from catastrophic defeat. Even a limited clash, decision not to act, or other encounter where American power is shown to be inadequate for its intended aims could prompt allies to reassess foundational assumptions that have long underpinned the US-led alliance system. What the example of Suez reveals is that it is not the scale of the military engagement itself that is critical, but the way in which a crisis reshapes allied perceptions of American reliability, capacity, and strategic will.
The British experience after Suez shows that military setbacks do not automatically spell the end of alliance networks. How structural and situational factors are managed in the aftermath matters. Should such a moment occur, the US faces two possible futures: one in which the American alliance system gradually hollows out, retaining formal institutions but losing substantive cooperation; and another in which alliances adapt to a new balance of power, with the United States transitioning from unchallenged leader to first among equals.
The direction and extent of change will depend on the resilience of shared strategic identity, Washington’s ability to sustain meaningful military contributions, and the emergence of leaders willing to reinvigorate cooperation in a more contested world. Compared to Britain in 1956, the United States still possesses unique strengths: a vast network of treaty allies, deep interoperability across platforms and commands, and enduring technological advantages. These strengths provide the scaffolding for a continued leadership role, even after a visible loss of primacy.
“Situational factors may also provide new openings for renewed US leadership.”
The existence of that possibility should not be interpreted as permission for complacency. Without urgent investment in capabilities, diplomacy, and alliance maintenance, such scaffolding could become brittle. America’s alliances are resilient, but not unbreakable. They depend on allied perception of US value and resolve remaining credible. A Suez moment, if mishandled, could erode that credibility beyond repair. If managed wisely, however, it could become a catalyst for renewal. If China materially outpaces the United States in the coming decades, Suez provides the example of a painful but necessary recalibration that could sustain US relevance in a world where primacy may no longer be possible—but only if the United States recognizes the hand it has, and plays its cards wisely.
Bence Nemeth is cofounder and executive director of the King’s Centre for Defense Economics and Management and a senior lecturer (associate professor) in the Defense Studies Department at King’s College London, where he teaches military officers at the UK Defense Academy in Shrivenham, UK. He is the author of How to Achieve Defense Cooperation in Europe?—The Subregional Approach (Bristol University Press, 2022). Before joining King’s, he served as a defense planner for eight years in the Hungarian Ministry of Defense. Dr. Nemeth holds a PhD in defense studies from King’s College London and an MBA in defense systems management from the US Naval Postgraduate School in Monterey, California.
Image: Looking south toward el Cap, which is just on the horizon, November 1956, via National Army Museum, London.63
© 2026 Bence Nemeth