The past five years have witnessed a resurgence of regionalism in world politics. Old regionalist organizations have been revived, new organizations formed, and regionalism and the call for strengthened regionalist arrangements have been central to many of the debates about the nature of the post-Cold War international order. This book brings together the many different institutions and ideas to be found under the label of "regionalism"; it places the revival of regionalism in a broader historical perspective; it asks whether there are common factors behind the revival of regionalism in so...