The question of where, and with whom, power lies in the post Cold War world is explored here. The authors identify and discuss the factors which make the United States the world leader in the 1990s, and consider the strengths and weaknesses of countries which may be on the way to becoming leaders in Europe (Russia and the European Union) and Asia (Japan and China). The authors' main argument is that the world is becoming 'unitripolar' with the United States as its pivotal, though not fully hegemonic, power.