Ideology or indifference? Comparing the effects of ideological cohesion and great power involvement in Latin American regionalism

Given the sharp electoral swings in Latin America in the last twenty years and ensuing effects on regional cooperation, current literature has emphasized the importance of presidential ideology for regional institutionalization in this part of the world. This focus on domestic and regional factors, however, ignores the role played by extra-regional forces, notably the involvement of external powers; an increasingly salient variable in the current scenario of global competition between the US, China and Russia. We propose a framework combining these systemic and regional factors in explaining regional institution-building. We test the effects of great power intrusion/disengagement and ideological divergence/convergence in producing institutional strengthening or weakening via four case studies, analyzed through secondary sources and interviews: Mercosur’s reformulation, Venezuela’s exit from the Andean Community, the creation of the Pacific Alliance and the paralysis of Unasur. Our conclusions suggest that ideology defines institutional outcomes, whereas the effect of intrusion depends on whether these engagements occur under unipolarity or great power competition.