On May 5, 1967, U.S. National Security Adviser Walter W. Rostow briefed President Lyndon B. Johnson that Peru had contracted to buy twelve Mirage 5 supersonic fighter jets from France, "despite our repeated warnings of the consequences." The first planes were delivered a year later, prompting the United States to withhold development loans from Peru as directed by the Conte-Long Amendment to the 1968 Foreign Assistance Appropriations Bill. Peru was the first Latin American country (with the exception of Cuba) to equip its air force with supersonic combat aircraft, and its decision spurred a dramatic qualitative and financial escalation in regional arms procurement, thereby defeating Washington's effort to control the latter.
The CIA qualified the "Mirage affair" as the "most serious issue" in U.S.-Peruvian relations at the time. The event demonstrated the growing desire of Peru and other Latin American countries to loosen the ties that bound them to Washington and exemplified France's drive to depolarize world politics during the Cold War. Demanded by the Peruvian military establishment, the Mirage deal also announced the golpe of October 1968 that ended the presidency of Fernando Belaúúnde Terry and ushered in the reformist military dictatorship of Juan Velasco Alvarado. In addition, it complicated relations between the White House, Congress, and the press in the antagonistic context of the Vietnam War. Finally, it further illustrated the diplomatic and economic stakes of military aircraft sales, as well as the appeal of the airplane as a symbol of national sovereignty and modernity.