Having spent time in China during the 2010 "crisis" there were many concerns about the US carrier being off the Korean penninusula. In my discussions, it was clear the Chinese did not have the ability to precisely predict the actions of the leadership. These informal discussions were with educated but not highly connected individuals.

 

They behave in a bi-polar fashion. In short the NK's require a lot of energy for very little return. We are officially at war with them, they have threatened us nuclearly, they do not have the full capability to act, but the stated intent is there, and time moves forward implying greater capacity. Time to pressure the Chinese to intervene with the agreement by all concerned. Russia may play the spoiler, a new tact they seem to be growing attached to.

 

Alternatively we may need to announce nuclear testing on the Korean pennisula north of the DMZ. Enough is enough as the NK are working in tandem with the Iranians. Those who sponsored them may need to feel the pain of dealing with an "unreasonable" USA. World markets would plummet, quite possibly destroying the gains the Chinese have made economically when no one is willing to trade with them for fear of destruction. A strike by NK will do that plus more. The question is, now or later?