Which event led to the United States entering World War II?

• A. The fall of Paris
• B. The invasion of Poland
• C. The attack on Pearl Harbor
• D. The sinking of the Lusitania

Answer: (C)

The event that pulled the United States into World War II was the attack on Pearl Harbor. When Japan launched a surprise assault on the U.S. naval base in Hawaii on December 7, 1941, it directly violated American territory and prompted Congress to declare war on Japan the next day. This marked a shift from U.S. neutrality to active participation in the war, and shortly after, Germany and Italy declared war on the United States, bringing the country into the broader conflict in both the Pacific and European theaters. Before this, the United States had been aiding its allies through loans and supplies but had not yet entered combat. The fall of Paris and the invasion of Poland were early, pivotal events in the war but occurred before U.S. entry. The sinking of the Lusitania happened in World War I and influenced U.S. involvement then, not WWII.