As pointed out in a comment by Greg “Blotto” Garrett on Larry Correia’s blog the famous quote supposedly by George Orwell:
People sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf.
The closest people have been able to find in his writings is:
Those who “abjure” violence can only do so because others are committing violence on their behalf.
Orwell also wrote of Kipling: “He sees clearly that men can only be highly civilized while other men, inevitably less civilized, are there to guard and feed them.”
Also pointed out by Garrett is that the most famous quote of Edmund Burke isn’t really true either:
The only thing necessary for the triumph of evil is that good men do nothing.
Don’t repeat my mistakes.