Why did japan bring the us into WW2?

Answer 1

It was a very bad miscalculation on the part of Japanese leaders. The US had been putting increasing pressure on Japan since 1937 to stop their invasion of China and withdraw from that devastated country, which would have required Japan to give up on its cherished aim of achieving the "Greater East Asia Co-Prosperity Sphere", with Japan as First Among Equals among the nations of Asia. Japan had only ended its feudal era in the 1860s and then began to modernize, and hence missed out on the great era of colonialism in Asia. By the time Japan was ready to begin to exploit its neighbors as colonies, the European powers had already gobbled up just about everything in Asia, and Japan's entire plan was based on the notion of ending this state of affairs and replacing the Europeans and the Americans with the Japanese as the dominant power in Asia.

Relations between the US and Japan only got worse in 1941, after the Germans conquered France and installed a puppet regime there, called the Vichy government. The French Vichy government "invited" Germany's ally, Japan, to occupy the French colony of French Indochina. When Japan did so, the US embargoed the sale of oil to Japan. Oil is the lifeblood of a modern military - without it, planes do not fly, ships do not sail, and tanks do not roll. Japan has no source of oil, so when the US completely cut off oil sales to Japan in July 1941, in an effort to force the Japanese to give up their aggressive plans for continuing conquests, the Japanese faced a choice. They had only an 18 month supply of oil on hand. They could either comply with US demands, and give up the great goal of dominating Asia, or, they could go conquer some new area which had oil. They chose the latter route. There was ample oil in the Dutch East Indies (Indonesia today). If you look on a map and draw a line between Japan and the Dutch East Indies, about midway is the Philippines Islands. The Philippines had been in US hands since 1898, as part of the US Republican Imperialists' plan to create an Empire for America in the Pacific. Most Americans did not want an Empire, but having displaced Spain, which had held the Philippines for three hundred years, the US could not grant the Philippines independence without the Japanese, Germans, British or Russians immediately rushing in to make the Philippines their own colony. The US had military bases in the Philippines, including the massive air base at Clark Field and the naval base at Subic Bay, and also army troops. The Japanese were reluctant to begin their planned invasion of the Dutch East Indies with these forces - which they saw as a threat - on the flank of their invasion route. So, the Japanese decided they must invade the Philippines to remove this potential threat to their main goal. And having decided on the invasion of the Philippines, the Japanese further decided that they might as well go ahead and do as much damage to the US Pacific Fleet as they possibly could, right at the outset, to remove that potential for interference, and so they decided on the attack at Pearl Harbor.

The miscalculation was that, in those days at least, a US president could not take the US to war on his own personal wish. The Japanese leaders who were militarists could take Japan to war whenever they wanted to do so, and did not stop to consider that the civilian government in the US might not be able to do the same. It is extremely unlikely that the people of the US would have supported going to war with Japan in 1941 no matter how many colonies of whichever European power Japan invaded. So, in their effort to ensure that the US would not suddenly go to war with them to stop their righteous plans for conquest, the Japanese hit upon the one plan that guaranteed that the US would definitely go to war with them, and prosecute that war with grim determination until the Japanese militarists were exterminated.