The start of the Second Sino-Japanese War, in 1937, generated friction between the Japanese Empire, the United States and the British Empire. The United States and the United Kingdom reacted to the Japanese military actions in China by imposing an embargo on raw metal followed by oil also sent covert military aid to the Kuomintang government. When Japan occupied Indochina, a French colony in 1940, the Western powers responded with an asset freeze and the closure of the Panama Canal to Japanese ships. Oil was especially important for Japan, they have a lacking of oil resources.
These measures threaten to strangle the Japanese economy, so that diplomatic negotiations began to lift. Diplomatic negotiations climaxed with the Hull Note of November 26, 1941, which was described by Prime Minister Hideki Tojo as an ultimatum, and they were asked to leave China. The Americans declared after the war that did not include the term Manchuria in China, but this was not clear to Tojo, who considered that request the departure of Manchukuo was an insult. Japanese leaders decided that they had only two choices: give in to the demands of the U.S. and the UK and withdraw from China, or increase the dimensions of the conflict and try to acquire oil sources in Southeast Asia. Delaying the decision only weaken the Japanese position. They finally settled on going to war.
In August 1939, Admiral Isoroku Yamamoto was appointed Commander of the Combined Fleet Pacific. In the spring of 1940, Yamamoto decided to change the war plan after observing the progress in the maneuvers of aircraft carriers. Yamamoto suggested that a single withering attack on Hawaii was an alternative to try to destroy the enemy fleet in the Pacific and to hold European and American colonies as Americans rebuilt the fleet again. Admiral Yamamoto correctly predicted that the UK, France and the Netherlands did not have the strength to defend their colonies due to the parallel war in Europe. Japan was very angry with the United States because U.S makes an embargo sale of oil to Japan. Japan has no source of oil; the embargo means war to Japan. Japan attack Pearl Harbor because it was the perfect place because it was the naval base and they wanted the U.S to be busy rebuilt the base so Japan can keep on expanding their empire.