How States Think: The Rationality of Foreign Policy

How States Think: The Rationality of Foreign Policy by John J. Mearsheimer and Sebastian Rosato offers a rigorous and intellectually disciplined defense of the claim that states are, in most cases, rational actors in international politics. At a time when foreign policy failures are frequently attributed to irrational leaders, cognitive biases, or emotional decision-making, the authors challenge this prevailing narrative by carefully redefining what rationality actually means in the context of foreign policy. Rather than equating rationality with success or moral correctness, they argue that rational state behavior is best understood as decision-making based on credible theories about how the world works and shaped through a deliberative process among key policymakers.

The book is firmly grounded in a realist understanding of international politics, emphasizing that states operate in an anarchic system with no higher authority to guarantee their security. This condition of anarchy creates persistent uncertainty and the ever-present possibility of conflict, compelling leaders to think strategically about survival and power. Within this environment, Mearsheimer and Rosato argue, policymakers rely on theories—explicit or implicit—to interpret threats, predict outcomes, and choose among policy options. Rationality, in their view, lies not in perfect foresight but in the disciplined use of theory and structured debate under conditions of uncertainty.

A central contribution of the book is its distinction between strategic rationality and goal rationality. Strategic rationality concerns how states select means to achieve their objectives, while goal rationality addresses the nature of the objectives themselves. The authors contend that states almost always pursue rational goals, particularly survival and self-preservation, and that there is little evidence to support claims that states routinely sacrifice their security for ideology, prestige, or domestic political gains. This argument directly challenges strands of scholarship that portray states as reckless or self-destructive actors and reinforces a core realist assumption about the primacy of survival in international politics.

Mearsheimer and Rosato also engage extensively with competing approaches to rationality. They critique rational choice theories that reduce decision-making to expected utility maximization, arguing that such models oversimplify how policymakers actually think. At the same time, they push back against political psychology perspectives that equate deviations from optimal outcomes with irrationality or bias. By positioning their framework between these approaches, the authors offer a more historically grounded and empirically sensitive understanding of rational decision-making that reflects the realities of policy formulation at the highest levels of government.

The empirical heart of the book lies in its detailed examination of historical cases of both grand strategy and crisis management. Decisions such as Japan’s attack on Pearl Harbor, U.S. crisis management during the Cuban Missile Crisis, and NATO expansion after the Cold War are presented not as products of madness or incompetence, but as outcomes of rational processes shaped by prevailing theories and available information. Importantly, the authors do not claim that states are always rational. They explicitly identify cases of nonrational behavior—such as the Bay of Pigs invasion and the 2003 Iraq War—where flawed theories, poor deliberation, or both undermined rational decision-making. This balanced treatment strengthens the book’s credibility and avoids turning rationality into a blanket explanation for all state behavior.

While the book’s arguments are persuasive, its strong state-centric and realist orientation leaves limited space for domestic politics, non-state actors, and psychological influences that many scholars consider important in contemporary international relations. Nevertheless, this is less a flaw than a conscious theoretical choice, and the authors are clear about the scope and purpose of their framework.

How States Think is a significant contribution to the study of foreign policy and international relations theory. It compels readers to rethink easy assumptions about irrationality and to take seriously the intellectual processes that shape state behavior. By combining theoretical clarity with rich historical analysis, Mearsheimer and Rosato provide a framework that is valuable not only for academics and students of international relations, but also for policymakers seeking to understand—and improve—how states think and act in a complex and dangerous world.