It's likely a paraphrase of the Jean Rostand quote: "Kill one man, and you are a murderer. Kill millions of men, and you are a conqueror. Kill them all, and you

It's likely a paraphrase of the Jean Rostand quote: "Kill one man, and you are a murderer. Kill millions of men, and you are a conqueror. Kill them all, and you are a God." It's in the same category as the ancient "history is written by the victors." So either cynical or realistic (depending on your perspective).