The past decade has 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. The number, scope and diversity of regionalist schemes have grown significantly since the last major ‘regionalist wave’ in the 1960s. Writing towards the end of this earlier regionalist wave, Joseph Nye could point to two major classes of regionalist activity: on the one hand, micro-economic organizations involving formal economic integration and characterized by formal institutional structures; and on the other, macro-regional political organizations concerned with controlling conflict. Today, in the political field, regional dinosaurs such as the Organization of African Unity (OAU) and the Organization of American States (OAS) have re-emerged. They have been joined both by a large number of aspiring micro-regional bodies (such as the Visegrad Pact and the Pentagonale in central Europe; the Arab Maghreb Union (AMU) and the Gulf Cooperation Council (GCC) in the Middle East; ECOWAS and possibly a revived Southern African Development Community (SADC, formerly SADCC) led by post-apartheid South Africa in Africa), and by loosely institutionalized meso-regional security groupings such as the Conference on Security and Cooperation in Europe (CSCE, now OSCE) and more recently the ASEAN Regional Forum (ARF). In the economic field, micro-regional schemes for economic cooperation or integration (such as the Southern Cone Common Market, Mercosur, the Andean Pact, the Central American Common Market (CACM) and CARICOM in the Americas; the attempts to expand economic integration within ASEAN; and the proliferation of free trade areas throughout the developing world) stand together with arguments for macro-economic or ‘bloc regionalism’ built around the triad of an expanded European Union (EU), the North American Free Trade Area (NAFTA) and some further development of Asia-Pacific regionalism. The relationship between these regional schemes and between regional and broader global initiatives is central to the politics of contemporary regionalism.