Also, Russia is going to want a say in matters as well since they also border North Korea.
Perhaps, they should do like Germany after World War II and divvy up North Korea into four zones: South Korea, US, China and Russia for a period of time before allowing it to reunite with the South. It may take a generation for North Korea to be ready to join the South, as their people have been so brainwashed.
Russia would probably help with the polonium salad dressing................