My high school literally taught us, not even slightly critically, that Stalin and Hitler were allies who started the war by invading Poland together.

My favorite thing about that insane idea is that it's called a non-aggression pact - You don't need a non-aggression pact with your allies! You don't have to agree with your allies "We won't kill you yet," it's already assumed! That's what makes you allies!

It's like saying parents were allies working together to split up the kids because they signed a divorce agreement.