In his book The War Trap Bruce Bueno de Mesquita claims to offer a deductive theory of international conflict based on the assumption that foreign policy makers attempt to maximize their expected utility. The theory is subjected to a systematic empirical test that seems to provide impressive confirmation. The first part of this article examines Bueno de Mesquita's theory and argues that it cannot be derived from his assumptions. The second part examines the operational version of the theory, which was the one actually tested, and argues that it can be more plausibly interpreted as a version of a different theory—one that Bueno de Mesquita claims to have discredited. The essay concludes by discussing the significance of this book with regard to the question of whether theories of individual rational choice can explain foreign policy decisions.