Rational choice theory has long been criticized, with several recent critiques of applications in political science in general and international relations in particular. In this paper, I seek to clarify discussion about rationality in several ways. I discuss the role of assumptions in theory and the assumption of rationality in rational choice theory. I demonstrate that many critiques of rational choice theory have been misguided , since instrumental rationality-the rationality of rational choice theory-is applicable to a wide variety of social situations, including situations where various psychological, informational, and structural factors claimed to interfere with rational decision-making are present. I also focus on three applications of rational choice theory in international relations that demonstrate ways that rational choice theorists have potentially added to confusion about the rationality assumption and created disillusionment in others about the rational choice enterprise. Finally, I point out that, since rational choice theory is not a single theory, critics' claims about the non-falsifiability of rational choice are immaterial. An understanding of these issues facilitates movement by the international relations community away from argument over the assumption of rationality and on to more productive and integrative theory building.