This article examines the relationship between international commercial banks and military regimes in South America. The focus is on how military regimes in the Southern Cone of Latin America and Brazil in the 1970s became heavily dependent on foreign capital provided by international banks based in Britain and France. It makes use of previously unavailable archival evidence to examine the interactions between international banks and South American governments, showing how these interactions intensified once military rule was established. It shows that international capital was used for a wide variety of purposes, including arms imports. When global banks cut loans once the debt crisis erupted in 1982, they aggravated the economic crisis but also fostered democratic change.