This volume explores the possibilities that rational choice and game theory have to offer for international relations research, using a variety of approaches. For instance, while paying due attention to the importance of bilateral representations of international situations in the form of two person games, it also covers co-operative problems in international relations at a multilateral level. In order to achieve this, it contains several pieces of work that are inspired by notions of coalition analysis and co-operative game theory. In order to cover the various aspects of the formal treatment of international co-operation, the volume is divided into five parts: general aspects, specific applications of game theory and co-operation, deterrence, escalation and crises, and finally other approaches to modelling international co-operation.