In the years since the 9/11 attacks, socially constructed understandings of the identity of the United States and its friends and enemies in the world have played a critical role in determining the course of U.S. foreign policy. "Constructing Twenty-First Century U.S. Foreign Policy" argues that American foreign relations under the Bush administration were driven by an ideological agenda derived from a particular interpretation of long-standing ideas about national identity. Drawing on constructivist and social-psychological IR theory, it suggests that these ideas led directly to the administration's choice to invade Iraq, its misunderstanding the kind of war the United States would face there, and its failure to quickly establish a stable democratic government following the invasion.

The history of twentieth-century American foreign policy presents an indictment of classical and structural realism and systemic theories of international relations more generally. Examining five crucial movements of transition in American foreign policy making - before and after each of the world wars and the end of the Cold War - Shonberg argues that the national interest resides mostly in the eye of the beholder, and that the idiosyncratic perceptions, beliefs, and values of individuals are of vital importance in the policy process. Thus, America's recent experiences in global politics, interpreted through the lens of national ideology, has defined and created the ultimate shape of a new foreign policy.