A Theory of the Balance of Power in International Systems

Attempts at incorporating the assumption that national leaders pursue clearly defined objectives, and at applying the theory of cooperative games to the analysis of international systems, have led to little success in formalizing the concept of balance of power, and in providing a theoretical justification for much of the scholarly intuition about this concept. But by assuming that such leaders temper their desire to maximize resources by the goal of ensuring the survival of their countries, and by distinguishing between two forms of stability—one in which no nation's existence is threatened and one in which no nation's resources are threatened—we offer a model that yields necessary and sufficient conditions for both forms of stability. Our critical assumption is that before entering armed conflicts and before forming either offensive or defensive alliances, national leaders evaluate the future games that their current actions imply, and the consequences of participating in such games.