The most fundamental questions in international relations are: “Why do states go to war?” “How can interstate conflict be prevented or ameliorated?,” and “What are the pathways to greater international cooperation?” In considering these questions, the dominant paradigm in international relations, political realism, emphasizes the enduring propensity for conflict among self-interested states seeking their security in an “anarchic” international environment, that is, one where there is no central authority to protect states from each other or to guarantee their security. Hence, international cooperation is thought to be rare, fleeting, and tenuous – limited by enforcement problems and each state’s preference for larger relative gains in any potential bargain because of its systemic vulnerability (Morgenthau, 1949; Waltz, 1979). At the extreme, states find themselves in a security condition of mutual distrust that resembles a prisoner’s dilemma game. (See Box 3.1 in Chapter 3 for a description of various games.) Maintaining an equilibrium in the international system through a balance of power and limited cooperation are all that can be hoped for; a situation where war, large-scale violent conflict, is natural and merely “diplomacy by other means” (von Clausewitz, 1989). This is not to argue that international relations are in a constant state of war, rather that they exist within the shadow of war as a final arbiter.