Whither North Korea?

Medium duty dictator, Kim Jong Il, croaked last night. We have no idea what comes next. The South Koreans might have a clue, but we don't. Perhaps heir Kim Jong Un (28) has the stones to take over from his father and actually run the country. Perhaps the North Korean establishment will run things with Kim as a figurehead. Perhaps the North Korean regime will collapse under the pressure of starvation and famine.
The last possibility is the most worrisome. If the North collapses, the South Koreans will be under enormous pressure to do something. A lot of South Koreans still have kin in the North. They will demand relief efforts to keep their relatives from starving to death.
The Chinese have been very happy with North Korea. It gives them a friendly border state, who can tie the Americans in knots at the drop of a nuke. The idea of having a pushy capitalist South Korea, hand in glove with the Americans, on their border is anathema. So the Chinese are under pressure to intervene to save the communist regime in the north.
So now we have South Korean army units, trucks loaded with relief supplies and peace flags fluttering from bumper mounts, tooling around in the north, with Peoples Liberation Army units doing the same thing. The nasty possibilities should be obvious.
If things blow up, we will be under enormous pressure to back up the South Koreans. They are good people, lots of us have been to their country and come back impressed with their country, their industry, their people, and their army. We will see the issue as support of a loyal long time friend of America, against Communist aggression.
We don't really want to get into a scrap with the Chinese, with whom we do a lot of very profitable business, but we don't want to leave a long time friend in the lurch either.
With luck, this issue won't come to a head until we have replaced Obama with a real president.