This volume of essays, with a new introduction and connective sections, brings together John Gerard Ruggie's most influential theoretical ideas and their application to critical policy questions concerning the post-Cold War international order. The book is divided into three sections: the first part is concerned with international organization and explains how the "new institutionalism" differs from the old, introducing the concepts of regimes, epistemic communities, and multilateralism. The second part of the text, "The System of States", includes explorations of political structure, social time, and territorial space in the world polity. The role of institutions in change of the system in states is also considered. The final section "Making History" discusses America and the issue of "agency" in the post-cold was era, NATO and the future transatlantic security community and the United Nations, and the collective use of force.