Regional integration today increasingly shapes the relations between states and their actors and thus is to be considered a significant part of international politics. This volume brings together leading experts in the fields of international relations, foreign policy research, regional and area studies, integration research as well as law and economics, and provides a comprehensive overview of the most important regional integration projects worldwide. Furthermore, the most important theoretical approaches in political science as well as the international legal and economic fundamentals are illustrated and explained. The aim of this volume is to provide not just an introduction and classification of the different integration projects, but also to shed light on the historical foundations, the actors, the institutional structures, the different policy programs and development prospects of regional integration projects.