1. Japan became involved in WWII when they became allies with Germany
Japan became involved in WWII when they became allies with Germany. They wanted to fight against communism and to control East Asia.
Japan felt threatened by America because they had navy ships stationed in Hawaii, only a few thousand miles from Japanese shores.
Japan entered into war by invading parts of China, a communist country in 1937.
After considering other options, the United States decided to drop an atomic bomb on the Japanese military cities of Hiroshima and Nagasaki. This forced Japan to surrender.
Japan attacked the US Navy station at Pearl Harbour in Hawaii.
The Americans considered this an act of war and officially entered WWII.
The United States and Japan fought a war in the Pacific Ocean and Japanese forces were pushed back closer to the home islands by 1943.