The Iraq war was a multiple assault on the foundations and rules of the existing UN-centered world order. It called into question the adequacy of existing institutions for articulating global norms and enforcing compliance with the demands of the international community. The war was simultaneously a test of the UN's willingness and ability to deal with brutal dictatorships and a searching scrutiny of the nature and exercise of American power. The UN Security Council is the core of the international law enforcement system and the principal vehicle for pursuit of multilateral goals. The United States' emergence as sole superpower after the cold war distorted the structural balance in the UN schema. The United States has global power; the United Nations is the fount of international authority. Progress toward a world of a rules-based, civilized international order requires that U.S. force be put to the service of lawful international authority. This book examines these major normative and structural challenges from a number of different perspectives.