How do nationalist beliefs shape and influence American foreign policy? What are the contemporary implications of America's long-standing engagement in the Asia Pacific? This book unearths the varied processes underpinning the relationship between nationalism and the formulation of foreign policy, highlighting the central function of leaders' nationalist beliefs in the history of America's international behavior. By developing a novel theoretical framework and drawing on original archival research and methods of process-tracing, Paparella shows how presidents' nationalist beliefs can influence distinct foreign policy attitudes that have underpinned important foreign policy decisions and turning points in the Asia Pacific. By putting nationalism back on center stage, Paparella makes a strong case for looking at this history as a complex succession of interactions—between states, but also between leaders—that are highly contingent and shaped by the nationalist views of the leading US decision-makers over time. This thoughtful study provides scholars and students with an interpretative key to understand the multifaceted role of the United States in the Asia Pacific, as well as policy recommendations to overcome the security and the credibility challenges posed by the rise of China in the region today.