Japanese invasion of French Indochina
Following the 1931 Japanese invasion of Manchuria, beginning the Second Sino-Japanese War, Japan spent considerable effort trying to isolate China and to obtain sufficient natural resources to attain victory in China. The 1940 Japanese invasion of French Indochina was such an effort to control supplies. In response, the United States halted shipments of airplanes, parts, machine tools, and aviation gasoline to Japan. In July 1941, the U.S. ceased oil exports to Japan, leaving the Japanese with the option of either withdrawing from China or securing new sources of raw materials in the resource-rich, European-controlled colonies of Southeast Asia, such as present-day Malaysia (United Kingdom) and Indonesia (Netherlands), both oil producers.