The savage repression by the Salvadoran state in the 1970s and 1980s was a response to the tangible threat of revolutionary coalitions that united peasants, students, and workers. Those coalitions were possible in part because of the transformations within El Salvador’s communist left in the 1970s. Changes on the left resulted both from transnational exchanges of ideas and from encounters between Salvadoran communists and the constituencies they sought to organize. This chapter starts by examining the impact of the Chinese and Vietnamese revolutions on the leaders of the Fuerzas Populares de Liberación Farabundo Martí (FPL), the largest of the five factions that would later comprise the FMLN guerrilla coalition. Drawing on leaders’ published writings and the propaganda of the FPL and affiliated organizations, it shows that China and Vietnam deeply influenced FPL leaders’ analysis of capitalism and imperialism as well as their strategy. Particularly important was those revolutions’ insistence on peasant primacy in the revolutionary struggle, which FPL leaders found highly relevant given El Salvador’s small urban proletariat. The FPL leadership applied this lesson not by neglecting urban sectors, but by building a coalition that could unite peasants, workers, and students. In this way they synthesized Chinese and Vietnamese ideas while also creatively adapting the older notion of the worker-peasant coalition that was most commonly associated with the Russian Revolution. Rank-and-file activists in El Salvador also contributed to the transformation of the FPL. Based on interviews with FPL leaders and rank-and-file organizers, it argues that the organization’s success depended on its willingness to accommodate its constituents’ political cultures and expectations: for instance, the FPL renounced its early insistence on atheism in order to appeal to people inspired by liberation theology. The evolution of the Salvadoran left’s thought and practice thus reflected transnational influences as well as pressures from its target constituencies.