Contrary to popular wisdom, some politicians in the United States apparently wanted Japan to attack America, so that the U.S. government could join the war in Europe. During the 1930s, the U.S. strategy toward Japan evolved from “non-recognition of its invasion of Manchuria, to political neutrality, to trade embargo, to a combination of forward basing of the U.S. Fleet and trade cessation.”1 U.S. deterrence ultimately backfired, however, because the emperor chose a military strategy that had a remote hope of success over an even higher likelihood of regime change at home if Japan backed down after incurring such huge human and financial costs in China. Coincidentally, when Japan attacked Pearl Harbor, some American politicians celebrated, knowing that by this act the United States could now enter the war in Europe.

As Japan expanded its empire first into Manchuria (1931–33), then into North China (1934–36) and finally throughout Central and South China (1937–45), the U.S. government adopted a low-cost strategy starting with non-recognition. But Congress passed a succession of neutrality acts starting on 31 August 1935 that forbade trade with either side in a war. On 5 October 1937, Roosevelt's famous quarantine speech signaled the U.S. judgment that Germany and Japan were both pariah states. Thereafter, in mid-1938, the United States began escalating trade restrictions on the war materiel necessary for Japan to continue hostilities in combination with forward basing of the U.S. fleet at Hawaii starting in 1940.

Embargo seemed like a highly promising strategy, given Japan's overwhelming dependence on raw material imports for war materiel production. On 11 June 1938, in response to the many Chinese civilian deaths from the Japanese bombing of Guangzhou (Canton), Secretary of State Cordell Hull imposed a “moral embargo” on U.S. exports of aircraft and equipment. By June 1940, the U.S. government had instructed U.S. customs authorities not to permit certain equipment exports to Japan and on 2 July 1940, Congress passed the “Act to Expedite the Strengthening of National Defense” (the Export Control Act), which authorized the president to prohibit the export of war materiel and strategic resources in order to stockpile them at home.