In the second half of the twentieth century, the United States engaged in the most ambitious and far-reaching liberal order building the world had yet seen. This liberal international order has been one of the most successful in history in providing security and prosperity to more people. But in the last decade, the American-led order has been troubled. Some argue that the Bush administration, with its war on terror, invasion of Iraq, and unilateral orientation, undermined this liberal order. Others argue that we are witnessing the end of the American era. Liberal Leviathan engages these debates. G. John Ikenberry argues that the crisis that besets the American-led order is a crisis of authority. A political struggle has been ignited over the distribution of roles, rights, and authority within the liberal international order. But the deeper logic of liberal order remains alive and well. The forces that have triggered this crisis - the rise of non-Western states such as China, contested norms of sovereignty, and the deepening of economic and security interdependence - have resulted from the successful functioning and expansion of the postwar liberal order, not its breakdown. The liberal international order has encountered crises in the past and evolved as a result. It will do so again. Ikenberry provides the most systematic statement yet about the theory and practice of the liberal international order, and a forceful message for policymakers, scholars, and general readers about why America must renegotiate its relationship with the rest of the world and pursue a more enlightened strategy - that of the liberal leviathan.