
Because Japan was poor in natural resources, its government viewed these steps, especially the embargo on oil, as a threat to the nation's survival. increased military and financial aid to China, embarked on a program of strengthening its military power in the Pacific, and cut off the shipment of oil and other raw materials to Japan. The United States, which had important political and economic interests in East Asia, was alarmed by these Japanese moves. Then in 1940, the Japanese government allied itself with Nazi Germany in the Axis Alliance, and, in the following year, occupied all of Indochina. In 1937 Japan began a long and ultimately unsuccessful campaign to conquer the rest of China.

In 1931 Japan conquered Manchuria, which until then had been part of China.

The road to war between Japan and the United States began in the 1930s when differences over China drove the two nations apart.
