In the aftermath of the post-Cold War era an important focus has been placed on the intensification of international relations as well as on the restoration of global governance enduring institutions. Regionalism and regionalization have been the well-worn answers to the question: how? Regional groups from different world regions started to innovate their relations on a forward-looking basis, and the EU has been central to the development of this new interregional phenomenon. This thesis sets out to test the EU commitment for inter-regionalism by looking at how the EU has strategically pursued it in Latin America’s South Cone region, and at how this has subsequently worked in the bi-regional relations with Mercosur after the rise of Brazil. The thesis explores the neoclassical realist declination of the EU coherence between its regionally oriented strategy rhetoric and the EU bilateral actions, principally by drawing lessons from the EU's relations with Brazil, for the EU negotiations with Mercosur in particular.