Really ? This might sound like an anti-us rant, but the US has enough weapons to destroy the planet several times over and has a history of using them and invading foreign countries.
I would like to see the fall of NK, but seriously you cannot blame the Chinese for supporting NK in the past and mainly for one reason. That reason is that NK is the buffer zone between China and the 30,000 US troops stationed in SK. Heck what about the 40,000+ troops stationed in Japan.
NK was a pain in the rear end until G W Bush made them a target with the axis of evil thing. The US and international sanctions against NK, all this while trying and some cases disposing leaders in other countries like Libya and Syria.
But if you want to punish China, just send Trump to build a new golf course there.