What event prompted the United States to enter World War 2?

The event that prompted the United States to enter World War II was the attack on Pearl Harbor. This surprise military strike occurred on December 7, 1941, when the Japanese Imperial Navy launched an aerial attack on the U.S. naval base located in Hawaii. The attack resulted in significant loss of life and damage to the U.S. Pacific Fleet, destroying numerous ships and aircraft, and it galvanized public opinion in the United States in favor of entering the war.

Prior to this incident, the U.S. had maintained a policy of neutrality, despite being involved in various forms of support to Allied nations. The attack on Pearl Harbor was a catalyst that changed this stance overnight, leading Congress to declare war on Japan the following day, December 8, 1941, which brought the United States into World War II.

Other events mentioned, such as the invasion of Poland and the fall of France, were crucial in the broader context of the war, but they did not directly lead to the United States’ entry into the conflict. The bombing of Hiroshima occurred much later in the war, and it was a significant event in its own right, marking the use of atomic weapons in warfare.