In the event of NK going to war with the US, they might as well not bother turning up. The US, unlike their undertaking in Vietnam would not be restrained by fighting a war with one hand tied behind their back, it would be a very one sided affair backed by the availability of the biggest arms stockpile (nuclear and otherwise) in the world and Kim Jong-un would soon learn that parading down the high street every couple of weeks with his ballistic missiles and flag waving military personnel, won't actually count for much when it comes to the real thing.

My opinion, for what it's worth, is that China will lean on NK to behave itself and not keep trying to provoke the US.

The Chinese are not stupid, they are a wealthy nation and do a high percentage of their trading, with the west. I doubt if they would look too kindly on Kim Jong-un bringing about a war and thereby having a drastic effect on said trade with the west.

Coupled with that is the astronomical financial cost to them if they decided to back NK with military hardware, and personal in an all out war. They know that their financial and business power in the world, would very soon diminish.....................In other words, it is in their own interest to prevent a war that they might however unwillingly be dragged into.