Japan attacked Pearl Harbor on December 7, 1941. They attacked a United States naval base, which killed over 2,000 Americans. The attack on Pearl Harbor caused the United States to join World War II and is also remembered today as a tragedy in history.
Japan attacked the United States naval base at Pearl Harbor because they wanted to get rid of American threats in the Pacific. Japan wanted to capture Malaya and other places but they believed that the United States would try to interfere with their plans. In order to get them to not interfere, they took action and attacked Pearl Harbor.