Now see, sdurani, I'd say that the cats you describe definitely know they're bad guys, they're just delusionally sociopathic. Another word for that is "crazy." As for Hitler and bin-Laden, I think you could also say that a pathological need for vengeance played/plays a part in their motives.

gonk, Weber's scenario sounds an awful lot like current conflicts in any number of parts of the world. If you hadn't said it was sci-fi, I might not have guessed it was such.

One more interesting bad guy: Keyser Söze, Kevin Spacey in The Usual Suspects.