How do states know what lies in their national interest? Hironaka explores this issue through examination of colonial expansion, and other domains of state security and power. Given the critical role of interests in many social theories, surprisingly little research has been done on the question. Scholars routinely avoid the issue by inferring interests from observed action in a post-hoc and often tautological manner. Instead, Hironaka draws on organizational sociology as a starting point: Large organizational actors like states often experience great ambiguity regarding their interests. States function in a complex political and social world in which both state interests and the means of achieving those interests are often unclear. Hironaka proposes that states respond to this ambiguity by attending to and participating in discourses in the international community. Collective interaction revolving around interpretation of the "Great Powers" and significant international events (such as the outcome of major wars) provide the grist for an evolving international consensus regarding appropriate state strategies and behavior. When faced with ambiguity, states draw upon the international consensus to inform their interests. Consequently, the international community plays a critical role in shaping state policies -- and thus the conflicts that are likely to arise in the international system. Ann Hironaka is an assistant professor of Sociology at the University of Minnesota.