The hard part, I think, would be tracking down films that give a good sense of the causes and course of more-obscure things like Italy's invasion of Ethiopia. You'd need to find two or three good films on that. Spanish civil war? The invasion and occupation of Poland? The political maneuvering between the Nazis and Soviets before they went to war with one another? The Winter War? These have to be covered by a few films that could act to "teach" the events, but I don't know what those films are and bet most are non-English and not well-known in English, making them harder (for me) to track down.