Boom, coupled with the Japanese announcement that the situation is critically imminent... would not be surprised if the USA bombs the norther boarders of NK and deployed bomb-lets to prevent Russian and Chinese expeditionary forces prior to any real engagements as the hands off warning. If China enters NK, expect them to lose all their little Atolls.
Expect China to lose all trade with the USA! Yeah!
If war does come again to the Korean peninsula, and as much as the NK regime needs to be defeated, a war with China would be a nightmare that would no doubt lead to an even worse case scenario with Russia joining them. Militarily, the China of today, while not the U.S.A., is a far cry from the China of the 1950's.
A real WWIII, even if not nuclear, should be something we all hope, pray and work to make sure never happens.