The Bush administration's emphasis on a preemptive first strike doctrine,along with its resort to unilateral decision making and commitment to sustaining US hegemony in the world, has challenged the very fundamentals of both the world political order and American political institutions. In this work, leading American scholars explore how these policies have been made, the premises upon which they are based, and their possible consequences forUS domestic institutions and its position in the world. The workconcludes with analyses of the changing US relationship to the European Union and the United Nation nations, while offering different perspectives on the necessity of and the prospects for the new American empire.