POWER PARITY, COMMITMENT TO CHANGE, AND WAR

Starr (1978) argues that the initiation of war requires both opportuni ty and willingness. Most theories of international conflict, however, consider only one of these conditions. Power transition theory, which focuses on power parity as opportunity and negative evaluations of the status quo as willingness, is an exception. Although the logic of the theory is compelling and empirical support impressive, the theory suf fers from a lack of generalizability, and from inadequate conceptualiz ation and operationalization of evaluations of the status quo. We offe r preliminary corrections for both of these weaknesses by (1) depictin g the international system as a series of hierarchies rather than as a single hierarchy, thus providing some generalizability; and (2) using extraordinary military buildups to evaluate the relative commitment o f the challenger and the dominant power to the modification or mainten ance of the status quo, respectively. We argue that the probability of wars between contenders in local or international hierarchies increas es significantly when power parity is achieved, presenting the potenti al challenger with the opportunity to successfully challenge the domin ant state, and when the challenger's extraordinary buildup exceeds tha t of the dominant power, revealing its willingness and commitment to c hange. Empirical evaluation of the conflict behavior of major power co ntenders and of a subset of minor power contenders provides strong sup port for our reconceptualization of power transition theory.