Then again, you could also argue 1933, when Hitler took power, or 1941, when America started fighting. It's complicated. But anyway, in China the fighting was very brutal, as exemplified by the infamous Rape of Nanking, which featured the slaughter of hundreds of thousands of Chinese people, and is still so controversial today that 1. It affects relations between Japan and China, and 2. Even though I have not described it in detail, you can rest assured that there will be angry comments about my use of the word slaughter. But the World War II we know the most about from movies and TV is primarily the war in the European theater, the one that Adolf Hitler started. Hitler is the rare individual who really did make history.