Enhanced Cooperation Revisited offers a detailed and thought-provoking examination of one of the EU’s most discussed yet rarely applied tools for differentiated integration. Situated between supranational ambition and national sovereignty, enhanced cooperation allows groups of Member States to adopt EU law among them when unanimity proves to be out of reach —without changing the Treaties or creating opt-outs. The book explores enhanced cooperation as a legal and political mechanism that enables integration through flexibility. Departing from a thorough, yet innovative legal analysis and incorporating interdisciplinary insights, the study presents a fresh typology of enhanced cooperation uses, proposes innovative interpretations of its legal framework, and explores options like fast-track procedures and conditional participation, as well as a field-map of legal areas suitable for enhanced cooperation. A novel proposal for “incentivised cooperation” suggests a targeted Treaty amendment to make the mechanism more promising as a facilitating tool in the most contested policy areas. Enhanced Cooperation Revisited casts new light on a little-used but powerful tool in the EU’s integration arsenal—one that may yet help the European Union in reconciling unity and diversity in the years ahead.