Why did Japan attack on the US military base at Pearl Harbor in 1941?

Answer 1

September 1940. The U.S. placed an embargo on Japan by prohibiting exports of steel, scrap iron, and aviation fuel to Japan, due to Japan's takeover of northern French Indochina.

April 1941. The Japanese signed a neutrality treaty with the Soviet Union to help prevent an attack from that direction if they were to go to war with Britain or the U.S. while taking a bigger bite out of Southeast Asia.

June 1941 through the end of July 1941. Japan occupied southern Indochina. Two days later, the U.S., Britain, and the Netherlands froze Japanese assets. This prevented Japan from buying oil, which would, in time, cripple its army and make its navy and air force completely useless.

Toward the end of 1941. With the Soviets seemingly on the verge of defeat by the Axis powers, Japan seized the opportunity to try to take the oil resources of Southeast Asia. The U.S. wanted to stop Japanese expansion but the American people were not willing to go to war to stop it. The U.S. demanded that Japan withdraw from China and Indochina, but would have settled for a token withdrawal and a promise not to take more territory.

Prior to December 1941, Japan pursued two simultaneous courses: try to get the oil embargo lifted on terms that would still let them take the territory they wanted, and ... to prepare for war.

After becoming Japan's premier in mid-October, General Tojo Hideki See Books about Tojo secretly set November 29 as the last day on which Japan would accept a settlement without war.

The Japanese military was asked to devise a war plan. They proposed to sweep into Burma, Malaya, the East Indies, and the Philippines, in addition to establishing a defensive perimeter in the central and southwest Pacific. They expected the U.S. to declare war but not to be willing to fight long or hard enough to win. Their greatest concern was that the U.S. Pacific Fleet, based in Pearl Harbor could foil their plans. As insurance, the Japanese navy undertook to cripple the Pacific Fleet by a surprise air attack. See Books about Japanese Plans

Answer 2

Japan claimed they wanted to disable the US Naval Fleet so they could proceed with their plans to overtake the Dutch East Indies and other countries. They wanted oil and other resources of the other countries. They thought they would bomb the entire naval fleet but were unaware the aircraft carriers were elsewhere. They were misguided.