'The European Union and Interregionalism' is the most comprehensive study of interregionalism to date, providing a vigorous analysis of its role and functions in the architecture of global governance, and of the place of qualitative differences between regional actors in shaping interregional relationships. Regionalism itself is an established phenomenon, with regional politics becoming increasingly institutionalised. As a result, with the EU as forerunner, regions have begun to exert themselves in the external policy space, developing networks of relations including, prominently,...