Editors Edgar Grande and Louis W. Pauly and the contributors to this volume elucidate the meaning of ‘complex sovereignty’ through a set of conceptual and empirical studies including governance in the European Union and North America, the emergence of private-public partnerships, the adaptation of established international organizations, and the search for innovative mechanisms to manage risk. They reveal a fascinating and vitally important struggle to give coherence to a complicated governing system of multiple and overlapping hierarchies. This is an original, collaborative study crossing the disciplines of political science, international relations, sociology, and political economy.