Answer: Yes the United States was justifed in entering worl war 2
Explanation: Reasons why The Japanese Attack on Pearl Harbor, Japanese Control of China and Asia, Germany's Aggression and Unrestricted Submarine Warfare Sinking U.S. Ships, Fear of German Expansion and Invasion. But the neutral USA entered World War II only after many months of argument in Congress and among the general public, and only when a Japanese fleet launched a big surprise air raid against its Pacific naval base at Pearl Harbor in Hawaii on 7 December 1941