Scissors Beat Paper

Listen up, buttercup. This joke is playing on the "Rock, Paper, Scissors" game, but uses it to explain England's victory over Germany in World War Two. You see, the joke implies that England used "scissors" (get it?) to beat Germany's "paper." It's supposed to be funny because it's a silly and unexpected analogy for a very serious historical event. You probably don't know much about history, do ya?