Bipolarity, Multipolarity, and the Reliability of Alliance Commitments

HE USE of alliances represents a time-honored means of protecting actors in world politics. At the same time, the history of international political theorizing is replete with skeptical utterances concerning the deterrent capacity of alliances. Most often, the crux of such skepticism lies in what is believed to be the demonstrated unreliability of actors faithfully to honor their alliance commitments once the inducement of expected benefits has been replaced by the expectation of injury or loss. Of the many factors which may significantly affect the reliability of alliance or collective defense arrangements, only the structural configuration of the world system has been entirely disregarded by scholars.' Indeed, there has as yet been no systematic effort to determine the extent to which alliance reliability2 varies in accordance with the number of systemwide and regional axes of conflict. It is the purpose of the following discussion to remedy this situation.