Supporting regional integration has become a cornerstone of the European Union's relations with other regional groupings across the world. The policy has evolved considerably from modest beginnings in the 1980s to increasing commitments in both quantitative and qualitative terms in more recent years. This study examines the motivations that underpin this policy evolution, drawing on rich evidence from EU interregional relations with Mercosur, the Andean Community and Central America. By carefully tracing EU support for regional integration from the 1980s until today, Tobias Lenz argues that the underlying policy motivations of relevant EU actors have shifted from considerations of geopolitics to a geoeconomic impetus. This development has been accompanied by and interacted with a strategic rivalry with the United States. This study is of interest to students of EU external relations and comparative regionalism.