Japan had entered World War One expecting to gain German possessions in Asia and also to dominate large portions of China. As an island nation, Japan had limited natural resources and no oil at its disposal. It hoped to gain some territory in Asia with access to oil and other resources. During World War I, Japan had seized a number of islands off the coast of China and had issued twenty one "secret" demands to the Chinese; the effect of which would have made China a protectorate of Japan. When the British found out about the demands, Japan was forced to back down. At the Treaty of Versailles, Japan came away empty handed; it received nothing for its effort in the war. Reasons for this are unclear; although a substantial factor was the racism of Woodrow Wilson.
Resentment at Japan's treatment at Versailles caused the civilian government to lose control and power shifted to an ultranationalist military group. The Second World War actually began in 1931 when Japan invaded Manchuria and ultimately controlled most of China. The Japanese war cry was "Asia for Asians." They later attacked French Indochina after having signed the Tri-Partite Pact with Germany and Italy, which gave Japan a free hand in Asia. When the U.S. demanded that Japan withdraw and imposed embargoes on shipments of scrap metal and oil, The Japanese Prime Minister, Hediki Tojo, had to choose between war and submission to U.S. demands. He chose war, which led to the attack on Pearl Harbor and later led to the U.S. declaration of war against Japan.