Coercive diplomacy - the use of threats and assurances to alter another state's behavior - is indispensable to international relations. Most scholarship has focused on whether and when states are able to use coercive methods to achieve their desired results. However, employing game-theoretic tools, statistical modeling, and detailed case study analysis, Power Plays builds and tests a theory that explains how states develop strategies of coercive diplomacy, how their targets shield themselves from these efforts, and the implications for interstate relations. Focusing on the World Trade Organization, Power Plays argues that coercive diplomacy often precludes cooperation due to fears of exploitation, but that international institutions can solve these problems by convincing states to eschew certain tools for coercive purposes.