Many of the leaders of new nuclear powers sit atop regimes that are personalistic in nature, and thus less constrained by institutions or public opinion than more democratic regimes. Such authoritarian leaders have more freedom to allow their psychological proclivities to influence their decisions and behavior. These tendencies include four psychological biases that influence decision-making: overconfidence, the planning fallacy, the illusion of validity, and the prominence effect. The ubiquity of these biases challenges our existing assumptions about rationality and the nature of strategic stability. The introduction of new and potentially more dangerous weapons—including the use of artificial intelligence or hypersonic missiles—heightens the risk of misperception, miscalculation, increased time pressure, and other factors exacerbating the threats confronting the world’s nuclear powers. Lessons from both cognitive and evolutionary psychology are discussed, as well as some policy recommendations to help improve decision-making under conditions of dominant leadership styles.

How will advances in artificial intelligence impact strategic stability? A growing number of studies and reports assessing the ways that advances in AI could influence global politics focus on the potential risks to strategic stability from integration of AI into the nuclear domain, particularly in large language models and frontier AI. These risks come from multiple potential sources, including miscalculation by machines, sidestepping of human firebreaks to escalation, AI-induced accidents, the speed of AI-enabled warfare, and other mechanisms. The relationship between AI integration and strategic stability may change over time as knowledge and experience with AI systems increases, thus decreasing the likelihood of automation bias, but fundamentally the relationship will depend on second-strike capabilities. While there is inherent uncertainty since we are still early in the age of AI, at this point it appears as though the higher the confidence nuclear-armed states have in their second-strike capabilities, the lower the probability that they integrate AI in dangerous ways that make escalation at machine speed more likely, and vice versa.

Emerging technologies possess the potential to transform military competition and the international system in an uncertain, potentially destabilizing fashion. Are there ways to capture the benefits of these new technologies without unleashing catastrophic dangers? What insights and lessons can we glean from history—particularly from the Cold War experience the United States had with nuclear weapons—to help us navigate the challenges of today and tomorrow’s new technologies? This essay examines the concept of strategic stability, and in particular, the important ideas from the foundational thinker of the nuclear age, Thomas Schelling. For decades, strategic stability has been offered as both the prized goal and the great accomplishment of America’s nuclear statecraft, with Schelling acknowledged as the idea’s father. Examined closely, however, questions, tensions, and even contradictions appear, both in Schelling’s work and in the use of strategic stability to describe America’s nuclear strategy and statecraft.