What & When: In 1941, Japan conducted a surprise attack on the U.S. navy base Pearl Harbor killing over 2,000 soldiers.
Cause: Tensions between the U.S. and Japan had been building for years.
Effect: The U.S. entered into WII the next day and defeated the Japanese at Midway.
Significance: Japan's attack on Pearl Harbor caused the U.S. to enter WWII, which would contribute to the downfall of Nazi Germany and other Axis Powers.