It will happen if superpower countries wont reconcile (and i think reconcialition or agreement is somewhat impossible). I think it will start between China, North Korea and UsA.
If there is a military confrontation between North Korea and the United States, then in all probability Russia and China are going to remain at least nominally neutral. They will never send their soldiers to die as cannon fodder in Korea. However, we can expect North Koreans receiving military trainers and equipment from these nations.