Ironically, STD proved my point that there was not a single bit of character development in nuTrek 2009. Kirk is the very same bar brawler he was from the start. Spock NEVER learns to control his emotions. He turns into a psychopath in Trek 2009 when he gets annoyed, and he does it again in STD.
I think psychopath is a bit much.
Perhaps does his duty and defends the Federation and its interests against a guy who killed at least 40 people and is still a danger. Its not like Khan was going to retire to Ceti Alpha and start a new colony in peace.