Cold War strategic priorities led the United States to establish an enduring military alliance with General Francisco Franco's dictatorship in Spain between 1953 and 1975. This article examines the educational diplomacy carried out by the US government during the 1960s and early 1970s to foster Spain's stable modernization through the training of national development elites and the dissemination of US educational ideas. The work surveys US educational, informational, and cultural programs aimed at shaping an educational framework conducive to the expansion and legitimization of a US-oriented socioeconomic liberalization in Spain. On the one hand, this US soft power strategy sought to attract those groups who could play an important role in the capitalist modernization of the educational and economic structures of the Iberian country. On the other hand, it sought to reduce the identification of the United States with Franco's dictatorship and to link the image of the American superpower to the hopes for progress of the Spanish people. All of this was pursued in order to preserve US defensive interests in Spain. The piece also discusses US assistance to the crucial 1970 Spanish General Education Law, which allows us to explore how the US ideology of development and education was received by Spanish educational audiences. Thus, by delving deeper into the intersection between cultural diplomacy, international development, and the history of education, we aim to contribute to the integration of education into the histories of modernization and to deepen our understanding of US educational foreign policy in the Cold War.