The US Congress banned the sale of war material to Spain. Aware of the connection between Spain and South America, Washington feared at the time the influence of Franco's victory in America and accepted the embargo law in order to hinder Francoist victory.

Franco, however, was well supplied by Germany and Italy, with the Spanish Republic being the worst affected. In addition, the companies General Motors, Ford and TEXACO, led by fascist Thorkild Rieber, continued to sell arms to Franco.