Which event led the United States to fear invasion by Japan?

• A. The attack on Pearl Harbor
• B. The attack on Hiroshima
• C. The attack on Nagasaki
• D. The attack on Tokyo

Answer: (A)

The event that sparked widespread fear of a Japanese invasion was the surprise attack on Pearl Harbor. When Japan struck the U.S. Pacific Fleet at Pearl Harbor, it showed that American soil and its western defenses were vulnerable and that Japan could threaten Hawaii and other Pacific territories. That shock pushed the United States from neutrality into full-scale wartime mobilization, with rapid buildup of defenses and preparations for homeland security along the coast. The later atomic bombings of Hiroshima and Nagasaki were aimed at forcing a surrender and ending the war, not at signaling an imminent invasion of the mainland, and the attack on Tokyo did not represent an invasion threat to the United States.