Central America was a “hot spot” in the Cold War, constituting a strategic zone for US campaigns against communism from the 1960s to the 1980s. During the same period, the region was also a “hot spot” due to the critical nutritional situation of its poorest populations. Informed by the idea of a “protein gap,” international organizations and scientific institutions carried out field investigations and nutritional surveys to identify dietary deficiencies, their causes, and possible solutions. This chapter explores the role that bean varietal improvement played in this situation of war and nutritional crisis, and the political and social conditions under which bean research took shape. It describes the research programs that the International Center for Tropical Agriculture (CIAT) promoted in Latin America through the 1980s and Central American countries’ participation in these. It reviews the bean program established by CIAT in Latin America and Africa and a regional program created specifically for Central America and the Caribbean. It then interprets the evolution of these programs in the context of civil war and economic crisis in Central America between 1970 and 1990.