You don't think seeing what happened to Gaddafi has anything to do with it? Libya got rid of their nuke development plans in 2003. If Libya had nukes, would the Libyan revolution have played out as it did? Do you think Kim Jong Un wants to get dragged around, anally raped and murdered by an angry mob? Probably not.
> Perhaps China wants to annex NK.
Not even close. China would rather NK sank into the sea than try to take 25M malnourished, undereducated more people.