In contrast to previous studies of the South Korea-United States alliance, Uk Heo and Terence Roehrig analyze the bigger picture, including the history, economics, security, alliance structure, politics, and the future of the alliance. Taking alliance theory as a starting point, the authors argue that the alliance provides an ideal case study to examine how the political development and economic growth of junior partners impact an alliance. As South Korea's capabilities and ambitions have grown, the alliance has evolved from an asymmetric regional security relationship to an economic partnership with global interests, while China's rise and North Korea's nuclear development mean that South Korea remains of strategic importance for American interests in East Asia. This book will be read both as a major contribution to Korean studies and the study of alliance politics and theory.