How did the attack on pearl harbor cause the united states to enter world war 2

They used a counter attack on the pearl harbor from the rear because they thought no one would be looking at the rear of the vessel so hey went to the rear and they added a wooden propeller base for shallow waters because the torpedo they was using was for deep water and their plains were faster than what the us had.

After Japan started their campaigns in Asia, the United States sanctioned them and cut off all trade. They also started a massive military buildup in the Philippines and Hawaii to make the Japanese aware of their readiness. This is not to blame the soldiers who died at Pearl Harbor or to cast the Japanese as innocents - just understand that it wasn't entirely unprovoked or unexpected, either. The US had every intention of getting into the war because it and its allies had economic interests in Indochina and Manchuria, but they expected the Japanese to attack the Philippines fleet instead of the Hawaiian buildup.