"You would risk his life?" Khan cocks his head, something feral in his eyes. "Come now, Commander. We both know you value the lives of your crew. And you know I could snap his neck before you ever bring yourself to fire that phaser."

He'd learned ruthlessness as a child, caution not long after. Spock's attempt to goad him into a fight is as plain as daylight, and so Khan clings harder to the stalemate between them. It might be considered too reactive - he'd always been known for fighting defensive wars, after all - but if Spock wants this to end, he'll have to act first.

And that? That would just give Khan an excuse.