The end of the Cold War, as well as recent progress towards economic integration among countries in various regions, revolutionary advances in communications technologies, and the rapid emergence of global social networks, has resulted in profound transformations in structures of political authority around the world. The role of the modern nation-state continues to be crucial, especially for the production of public goods such as security and welfare, yet states cannot address the most pressing problems facing their own citizens without moving away from traditional understandings of sovereignty itself. "Complex Sovereignty" is an original, collaborative study crossing the disciplines of political science, international relations, sociology, and political economy. The essays in this volume examine the meaning of 'complex sovereignty' through a set of conceptual and empirical studies on such topics as governance in the European Union and North America, the emergence of public-private partnerships, the adaptation of established international organizations, and the search for innovative mechanisms to manage risk. Together, they elucidate a fascinating and vitally important struggle to give coherence to a complicated governing system of multiple and overlapping hierarchies.