What event brought the United States into World War II by attacking Pearl Harbor?

• A. The Japanese attack on Pearl Harbor on December 7, 1941
• B. The German invasion of Poland
• C. The Battle of Britain
• D. The Battle of the Atlantic

Answer: (A)

The direct trigger was the surprise Japanese attack on Pearl Harbor on December 7, 1941. This assault crippled the U.S. Pacific Fleet and shocked the nation, prompting President Franklin D. Roosevelt to ask Congress for a declaration of war against Japan. Congress approved it, and within days Germany and Italy declared war on the United States, bringing the country fully into World War II. The other events listed were important parts of the war’s broader context, but they did not by themselves draw the United States in.