It is quite the large dookie sandwich.
Conventional war on the Korean Peninsula would be damned ugly. There would be two humanitarian crises, the first being the massive amount of civilian casualties in Seoul and the surrounding areas, the second being integration with the North and South after the war was over.
China holds Kim's leash, so it's not going to happen. We get into a war with Korea, China backs the North, and the US simply voids all China's bond holdings as a result of their support of the north.
Russia, at that point, would be sitting on the sidelines laughing, as China is their enemy in more ways than one.