Why did Japan attack Pearl Harbor ?

There is allot of unnecessary anti US spin here and that is unfortunate. Japan only attacked the US because of the embargo and rising tension in the Pacific.. The soldiers, sailors and airmen on the ground did not see it coming but the US government and intelligence did. Here is the real reason why The escalating conflict between China and Japan influenced U.S. relations with both nations, and ultimately contributed to pushing the United States toward full-scale war with Japan and Germany. At the outset, U.S. officials viewed developments in China with ambivalence. On the one hand, they opposed Japanese incursions into northeast China and the rise of Japanese militarism in the area, in part because of their sense of a longstanding friendship with China. On the other hand, most U.S. officials believed that it had no vital interests in China worth going to war over with Japan. Moreover, the domestic conflict between Chinese Nationalists and Communists left U.S. policymakers uncertain of success in aiding such an internally divided nation. As a result, few U.S. officials recommended taking a strong stance prior to 1937, and so the United States did little to help China for fear of provoking Japan. In 1940 and 1941, President Franklin D. Roosevelt formalized U.S. aid to China. The U.S. Government extended credits to the Chinese Government for the purchase of war supplies, as it slowly began to tighten restrictions on Japan. The United States was the main supplier of the oil, steel, iron, and other commodities needed by the Japanese military as it became bogged down by Chinese resistance but, in January, 1940, Japan abrogated the existing treaty of commerce with the United States. Although this did not lead to an immediate embargo, it meant that the Roosevelt Administration could now restrict the flow of military supplies into Japan and use this as leverage to force Japan to halt its aggression in China. After January 1940, the United States combined a strategy of increasing aid to China through larger credits and the Lend-Lease program with a gradual move towards an embargo on the trade of all militarily useful items with Japan. The Japanese Government made several decisions during these two years that exacerbated the situation. Unable or unwilling to control the military, Japan's political leaders sought greater security by establishing the "Greater East Asia Co-Prosperity Sphere" in August, 1940. In so doing they announced Japan's intention to drive the Western imperialist nations from Asia. However, this Japanese-led project aimed to enhance Japan's economic and material wealth so that it would not be dependent upon supplies from the West, and not to "liberate" the long-subject peoples of Asia. In fact, Japan would have to launch a campaign of military conquest and rule, and did not intend to pull out of China. At the same time, several pacts with Western nations only made Japan appear more of a threat to the United States. First, Japan signed the Tripartite Pact with Germany and Italy on September 27, 1940 and thereby linked the conflicts in Europe and Asia. This made China a potential ally in the global fight against fascism. Then in mid-1941, Japan signed a Neutrality Pact with the Soviet Union, making it clear that Japan's military would be moving into Southeast Asia, where the United States had greater interests. A third agreement with Vichy France enabled Japanese forces to move into Indochina and begin their Southern Advance. The United States responded to this growing threat by temporarily halting negotiations with Japanese diplomats, instituting a full embargo on exports to Japan, freezing Japanese assets in U.S. banks, and sending supplies into China along the Burma Road. Although negotiations restarted after the United States increasingly enforced an embargo against Japan, they made little headway. Diplomats in Washington came close to agreements on a couple of occasions, but pro-Chinese sentiments in the United States made it difficult to reach any resolution that would not involve a Japanese withdrawal from China, and such a condition was unacceptable to Japan's military leaders. Faced with serious shortages as a result of the embargo, unable to retreat, and convinced that the U.S. officials opposed further negotiations, Japan's leaders came to the conclusion that they had to act swiftly. For their part, U.S. leaders had not given up on a negotiated settlement, and also doubted that Japan had the military strength to attack the U.S. territory. Therefore they were stunned when the unthinkable happened and Japanese planes bombed the U.S. fleet at Pearl Harbor on December 7, 1941. The following day, the United States declared war on Japan, and it soon entered into a military alliance with China. When Germany stood by its ally and declared war on the United States, the Roosevelt Administration faced war in both Europe and Asia.

Japan is an island nation (as I'm sure that you know!) and much of their landscape is mountainous and does not support crops and/or grazing land. Also Japan has a large population. Prior to World War II Japan and China had an uneasy history, and Japan had plans to expand and create more space for themselves to live and to grow crops and graze livestock. They also wanted to create a Japanese Empire in Asia. Most people agree that the Second Sino-Japanese War (the war between Japan and China) began on July 7, 1937 although China did not officially declare war on Japan until after the Japanese attack on Pearl Harbour. In July 1941, the United States, in support of China, issued an oil embargo on Japan. This embargo threatened to completely destroy Japans military campaign and their economy. Japan realised that it would not be long before the US was drawn into WWII and they recognised that they would be one of USAs first targets. They decided to strike first. Once again being an island nation is was always going to mean that it would be a Navy which would be the biggest threat against Japan. Planes were incapable of reaching Japan from the US without carriers and soldiers also would need to be transported by ship or carrier. Therefore the Japanese believed that it would be in their best interests to destroy the USA's naval fleet and therefore reduce the threat to themselves. On November 17, 1941 the United States ambassador to Japan sent a cable to the State Department warning that an attack by Japan on Pearl Harbor was imminent. However obviously the cable was ignored.

Because Japan had attacked and colonized parts of China, Korea, and South East Asia, which were allies of the US. The US wanted Japan to pull out of China and SE Asia. However, Japan wanted the raw materials in these regions. The Japanese millitary leaders didn't want to relinquish their source of natural resources, and they thought that war was unavoidable - so they decided to strike first at America and attack Pearl Harbor.

Oil What's up with the thumbs down it's true.

the japanese attacked the american fleet over a embargo of Oil. American forbid shipments of oil to japan thurs starving the japanese military of fuel and oil. so they attacked hopeing for a quick victory over america it failed

freakin american, they killed like a gazillion innocent people. like the vietnam war, fcking americans had to come over and bomb my dads house fcking assholes, it wasn't even supposed to be their fight, they just butted in. alot my family members died, they were trying to escape from the bombs being dropped by the fcking americans. and im not from the north, from the south baby!

The Japanese attacked Pearl Harbor because they knew America was going to have to enter the Pacific Theatre of WWII sooner or later. America's allies, China etc. were being attacked by the Japanese. The Japanese believed it would be a good idea to try and destroy all of the Aircraft Carriers in the Pacific. The attack was set up to do just that. Unfortunately for the Japanese. the carriers were not in Pearl Harbor so they destroyed almost every battleship, cruiser, supply ship, and plane in and around Pearl Harbor.

Japan was engaged in a war of conquest over much of southeast Asia in the 30s. The American response was to enact a trade embargo against Japan for oil and steel, as well as other raw materials. Japan has little of these resources, so the embargo could potentially cripple the Japanese war machine. So Japan chose to attack Pearl Harbor, where the majority of the US Pacific fleet was stationed. By knocking out Pearl Harbor the US would be crippled in the Pacific, and the Japanese would be free to conquer more territory, including areas that had the resources they needed. And they nearly succeeded, too. Fortunately the US aircraft carriers were out of port at the time of the attack, so they were saved. Aircraft carriers proved to be the most important part of the Navy in WW2, so the US was able to rebuild the fleet and go on to have victories at Midway and other locations in the WW2 Pacific theater.

because they believed America was going to attack them first the USA continually condemned Japan for its barbaric expansion into China