While much has been written about the United States’ efforts to undermine Nicaragua's Sandinista government (1979–90), historians have paid little attention to Latin American state perspectives on the only successful armed revolution in the region since Cuba. In fact, the war that subsequently emerged between Sandinista armed forces and US-backed contras was a thoroughly regionalized affair: at least 12 Latin American countries—including the five largest—became directly involved in efforts to broker peace by the mid 1980s. How and why did they become involved? What can Latin American diplomacy vis-à-vis the Sandinista Revolution tell us about the shape of inter-American relations in the twilight years of the Cold War?

To answer these questions, this article uses diplomatic archival sources and oral history interviews from Nicaragua, the United States, Mexico, Cuba, Costa Rica, and Panama to trace Latin American state responses to US intervention against the Sandinista government between 1982 and 1986. While the Reagan administration viewed Nicaragua as the place where it would begin to roll back Soviet-sponsored communism in the Third World, a bloc of Latin American governments—especially those associated with the Contadora peace process—saw Central America as the site where they would push back against US unilateralism and the threat it posed to their real interests and shared hopes for regional sovereignty. In stark contrast with the earlier reaction to the Cuban Revolution, most Latin American states rejected US intervention and sought to legitimize Managua's left-wing government. The regional dimensions of Nicaragua's civil war therefore show how the political fault lines of Latin America's Cold War shifted over time.