My dissertation explores strategies of collaboration and dissent around the implementation of a clandestine defense program in Latin America during World War II. In November of 1940, the U.S. government secretly subcontracted Pan American Airways to build and expand airports—as well as roads, radio towers, bridges, housing and hospitals—in strategic locations across Latin America through an endeavor called the Airport Development Program (ADP). 50,000 Latin Americans were employed at forty locations to carry out the work. After the attack on Pearl Harbor, many ADP sites became official U.S. military bases. My project looks at ADP defense sites as spaces in which the constant but ordinarily less visible interplay between international, national, and local agendas was made explicit. By exploring the implementation of the Airport Development Program and its aftermath at four sites in Cuba and Brazil from 1940 to 1961, I consider how this defense program intersected with long-term nationalist economic and political agendas of Latin American regimes as well as with local demands for health, labor and education initiatives. My dissertation aims to pair the strengths of transnational and international frameworks to assert a textured way of thinking and writing about inter-American relations that is not fixated solely on inter-state relations but rather recognizes multiple layers of inter- and trans- national contact.