Unpacking Rationality in Security Studies: Beyond Expected Utility and Towards Enriched Understanding of Strategic Decision-Making

The concept of rationality is foundational to the study of international security, often serving as a primary lens through which to analyze state behavior and strategic choices. While expected utility theory has provided a powerful framework for understanding rational decision-making, its limitations in capturing the complexities of real-world security dilemmas have become increasingly apparent. This article critically examines the prevailing definitions of rationality within security studies, particularly the dominance of expected utility theory, and advocates for a more nuanced, theory-driven approach to understanding strategic choices. Through a detailed re-examination of the Vietnam War, this analysis demonstrates how adherence to a narrow definition of rationality can obscure critical insights into policy failures and successes. By integrating insights from behavioral economics, cognitive psychology, and historical analysis, this paper argues for an enriched understanding of rationality that acknowledges the influence of uncertainty, cognitive biases, and the evolving nature of information in strategic environments.