To most Americans, the threat arising from Japanese and German aggression seemed very distant. Moreover, Hitler had more than a few admirers in the United States. Obsessed with the threat of communism, some Americans approved his expansion of German power as a counterweight to the Soviet Union. Businessmen did not wish to give up profitable overseas markets. Henry Ford did business with Nazi Germany throughout the 1930s. Indeed, Ford plants there employed slave labor provided by the German government. Trade with Japan also continued, including shipments of American trucks and aircraft and considerable amounts of oil. Until 1941, 80 percent of Japan’s oil supply came from the United States.
Many Americans remained convinced that involvement in World War I had been a mistake. Senate hearings in 1934-1935 headed by Gerald P. Nye of North Dakota revealed that international bankers and arms exporters had pressed the Wilson administration to enter that war and had profited handsomely from it. Pacifism spread on college campuses, where tens of thousands of students took part in a “strike for peace” in 1935. Ethnic allegiances reinforced Americans’ traditional reluctance to enter foreign conflicts. Many Americans of German and Italian descent celebrated the expansion of national power in their countries of origin, even when they disdained their dictatorial governments. Irish-Americans remained strongly anti-British.
Isolationism—the 1930s version of Americans’ long-standing desire to avoid foreign entanglements—dominated Congress. Beginning in 1935, lawmakers passed a series of Neutrality Acts that banned travel on belligerents’ ships and the sale of arms to countries at war. These policies, Congress hoped, would allow the United States to avoid the conflicts over freedom of the seas that had contributed to involvement in World War I. Despite the fact that the Spanish Civil War pitted a democratic government against an aspiring fascist dictator, the Western democracies, including the United States, imposed an embargo on arms shipments to both sides. Some 3,000 Americans volunteered to fight in the Abraham Lincoln Brigade on the side of the Spanish republic. But with Germany supplying the forces of Franco, the decision by democratic countries to abide by the arms embargo contributed substantially to his victory.