ABSTRACT
My explanation for why great powers vie with each other for power and strive for hegemony is derived from five assumptions about the international system. None of these assumptions alone mandates that states behave competitively. Taken together, however, they depict a world in which states have considerable reason to think and sometimes behave aggressively. In particular, the system encourages states to look for opportunities to maximize their power vis-à-vis other states.
