This book presents a radical intervention into the contemporary literature on liberalism, addressing the core problems surrounding liberal internationalism. Explaining the disjuncture between liberal theory and practice, it offers a firmer grasp on the historical role of liberalism in world politics. Despite the hegemonic position of liberalism after the end of the Cold War, liberal foreign policies like democracy promotion, humanitarian intervention and neoliberal economic policies widely failed to achieve their aims. This study provides a conception of liberalism that accounts for the successes as well as failures of these policies. It shows that the attempt to realize liberal principles in practice simultaneously generates nonliberal forces. This dynamic explains the tragic fate of liberalism in history: the moments of its greatest triumph give rise to its most serious crises. It suggests, therefore, that the main challenge for liberal foreign policies does not lie in confronting external threats but in designing policies that avoid internal fragmentation. Beate Jahn provides a focused debate and criticism of liberalism which has hitherto been avoided, locating the core principles of liberalism and applying them to politics, economics, and ethics. This book will be an essential source to all scholars of international relations theory and liberal foreign policy.