Khan would argue that he is exactly as he was made to be - not just a product of humanity, but above it. He and his kind were bred to be leaders, conquerors, and it was only once humanity had realized that they couldn't stand Augments in power over them that things had turned ugly.

Khan didn't start the Eugenics Wars. But he did his best to end them.

"And why would you do that, doctor?" He cocks his head, words enunciated with slow, careful precision. "You know who I am. You know what I can do. I've already injured one of the crew here. By all right, you should be running to your Captain this very instant."

Because Khan will not make a promise he doesn't intend to keep.