quote is from The Godfather

Edit: this was the quote

Michael: How bad do you think it's gonna be? Clemenza: Pretty goddam bad. Probably all the other Families will line up against us. That's all right. These things gotta happen every five years or so, ten years. Helps to get rid of the bad blood. Been ten years since the last one. You know, you gotta stop them at the beginning. Like they should have stopped Hitler at Munich, they should never let him get away with that, they was just asking for trouble.

quote is from The Godfather