This appears to be entirely fictional. But it is true that Charlie Chaplin had some connection with war between Japan and the US. In 1932 Charlie Chaplin travelled to Japan and and was a target of
coup plotters who hoped that murdering him would start a war with America. They apparently didn't realize that he was still a British citizen.
One of the mysteries of WWII is why Hitler declared war on the US after Pearl Harbor when he didn't have to. This focus on the reason for Japan's decision to go to war makes Hitler's motivation obvious--it was because of the Charlie Chaplin movie mocking him (The Great Dictator.