Though the armed forces in Latin America have rarely been at war, after a long period of military authoritarianism came to an end in the 1980s, they found themselves frequently under siege. The return to civilian governments and transitions to democracy, often under leftwing administrations instinctively hostile to military authoritarianism, confined the armed forces to the barracks and placed them under new pressure to conform to global norms of conduct. It might be assumed that this transformation brought with it new attitudes and a new outlook within the military institution itself – but while that is possible, we do not know for sure because there is limited empirical research on security thinking in Latin America and how past defence priorities have been transformed by changing attitudes elsewhere. Moreover, the outlook of the most powerful external sponsor of Latin America’s security establishment – the United States – has been in a state of nervous flux since the 1990s as its policymakers have reconsidered, or in some cases revived, established threats and found new ones to confront.