We may have to revise our evil rating then, since there's been few evils greater than Hitler in our history (I think) 
Hitler is among the most well-known and has a logical fallacy based around him, and thus is a suitable measuring stick.
Wait, how was a guy who helped end the Cold War 3.44 million times more evil than Hitler?
That's something of an exaggeration, but Kissinger is one of the most bloody-handed bastards in U.S. history.
Okay, I require an explanation. A quick browsing of his wiki page (assuming we're talking about the same guy) shows that he was heavily involved in peace efforts, not killing.