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. Specifically, he made it worse. And if he hadn't existed, it's very unlikely that World War II would have ever happened. But he did exist.