Since the Second World War, the Cold War and the welfare state have been among the largest historical shifts. This book examines the relationship between the two to uncover the impact of international context on social policy developments. The Cold War and Welfare State Development in Industrialized Countries offers a comparative and interdisciplinary perspective on whether, how, and to what extent the Cold War influenced the development of the welfare state in European and North American countries between 1947 and 1989. Linking the two master-narratives of the postwar era, it provides a systematic analysis of possible causal mechanisms linking the Cold War and the welfare state. It offers an innovative perspective on how the international context framed and affected, first, the massive expansion of social security and welfare programs during the so-called Golden Age of the welfare state, and second, during the period of welfare state crisis and re-structuring since the late 1970s. It considers the systemic competition between capitalism and communism and its influence on welfare state development through five main causal mechanisms. In so doing, it scrutinizes the Cold War's impact on the same set of policies across a broad selection of comparable industrialized countries and demonstrates both theoretically and empirically that national security and social security developed together during the Cold War era.