Why did Japan attack the United States to begin with?

Answer 1

The Japanese were desperate. During WW1 Japan had been America's ally. When Japan tried to collect her share of the booty at Versailles she ran into Woodrow Wilson. Wilson rejected Japan's claim to this which Japan had captured at a price in blood. In 1921 at the Washington Naval Conference, the U.S. pressured the British to end their 20-year alliance with Japan. The Brits appeased the U.S. and enraged and alienated Japan that had been a loyal friend, and so it went. Japan decided to create in China what the British had in India, a vast conlony to exploit to bring her up amongst those in world power. In 1937 after a clash at Marco Polo Bridge near Peking, Japan invaded and after 4 years of fighting, Japan controlled the coastal cities, but not the interior. Japan moved into northern French Indochina and though the U.S. had no interest there imposed an embargo on steel and scrap metal. After Hitler invaded Russia in June 1941 Japan moved into southern Indochina. FDR ordered all Japanese assets frozen. FDR didn't want to cut off oil, but unbeknownst to him at the time the action took place Japan was oil-starved and was blocked by any Japanese purchases of U.S. oil. Forcing a choice between death of the empire or fight for it's life Japan decided to seize oil fields in the Indies and the only force capable of interfering was the U.S. fleet that FDR had conveniently moved from San Diego out to Honolulu. And so ... Japan attacked!

Answer 2

They wanted to take over the oil and rubber in Indonesia, but the Philippians were in the way (They were U.S. controlled then), so they wanted to attack first, severely cripple our fleet, so they could take over the Philippines and then Indonesia.