HEGEMONIC SYSTEM AND INTERSTATE CONFLICTS: U.S. SUPPORT BEHAVIOR IN MAJOR REGIONAL ARMED CONFLICTS Qin Yaqing（51） This study argues that during the entire Cold War era, the United States was more likely to support antagonists of a regional leader in intra-regional armed conflicts and antagonists of a stronger regional leader in inter-regional armed conflicts. Furthermore, it hypothesizes that the more powerful a regional leader was, the more likely the United States would side with its antagonists. These hypotheses are tested by using a statistical model and all the 122 armed conflicts involving regional leaders from 1946-1988. The findings are supportive of the hypotheses.