Contending rationales of peace and conflict coexist between countries and within regional spaces as conditions that motivate or constrain militarized behaviors. While the idea of balancing is still a relevant concept to understand contemporary security in South America, the region produces patterns of a nascent security community. This article argues that the regional repertoire of foreign and security policy practices draws on a hybrid security governance mechanism. The novelty brought by the cumulative interaction among South American countries is that the coexistence turns into a hybrid between both practices and discourses. To explain how hybrid formations are produced, this study analyzes the most empirically intense and academically controversial political and security interactions from interstate relations in the two security complexes in the region, the Southern Cone and the Northern Andes.