Final answer:
The U.S. entered WWII in response to Japan's bombing of Pearl Harbor.
Step-by-step explanation:
The U.S. entered into WWII as a response to Japan's bombing of Pearl Harbor. On December 7, 1941, Japan launched a surprise attack on the U.S. naval base located in Pearl Harbor, Hawaii. This attack led to the United States officially joining the war against Japan, Germany, and Italy, forming the Allied Powers.
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