The Japanese launched a surprise attack on the US Navy base at Pearl Harbour, Hawaii on December 7th, 1941. They destroyed many American battleships and planes, killing over 2,400 American soldiers. This attack drew the United States into World War II by provoking a declaration of war against Japan. Pearl Harbour was a major US naval base located in the Pacific Ocean between California and Japan. The Japanese had intended to weaken the US Pacific fleet stationed at Pearl Harbour to prevent America from interfering with their expansion in Asia.