This is the book for which many have waited. Over the last decade, the authors, singly and jointly, have published a series of fascinating articles that challenged the conventional dichotomy of intergovernmental and supranational interpretations of European Union politics. The present volume synthesizes and extends these analyses, demonstrating not only the superior plausibility and internal consistency of the multi-level perspective, but also the wide range of research questions to which it can be usefully applied. Among the highlights are not only definitive accounts of the rise and decline of multi-level cohesion policies, but also sophisticated analyses of multiple identifications at the level of constituencies and of divergent orientations toward European integration among Commission officials and among national political parties. Altogether, this volume combines a wealth of empirical information with incisive analyses that are integrated in a convincing theoretical framework. A must for every student of European Union politics.