I figured it already is. China could make N Korea stop their shenanigans any time, but they don't. I figure they like having them there most the time stiring things up. And if they wanted to actually start trouble having them start it would provide a layer of deniability.

NK's nukes are just as much pointed at China as they are pointed at the US/SK. If China decides to choke off their oil NK will be sure to remind China that if their regime falls, they'll be sure to lob some missiles in China's direction first. Thinking of NK is purely a Chinese puppet instead of an independent actor with their own wants and freedom of action really limits the geopolitical cards the US could play here. Imagine if the US could flip NK like how Nixon flipped China against the USSR.

That's cute. China would not allow NK to become a friend of the US. There are so many ways to shut that down.

Many ways that would cost China and NK much more than the US. That's how you play the game, make it hurt more for your opponents than yourself. Right now, even the possibility that NK could flip to the US makes China treat NK with baby gloves, and as a result they have a nuclear capable country right on their border. You think China's leaders are happy about that? It's another potential hotspot they have to worry about that could spill into China in addition to all the other hotspots they have to deal with thanks to the fact that China borders more countries than any other in the world. More stress on the Chinese government = more ways they can screw up. +1 for America.

Nitpick: s/baby gloves/kid gloves/g.

The "kid" in the phrase "kid gloves" doesn't refer to children. It refers instead to leather made from kid goats. Kidskin leather is thinner and softer than other kinds of leather, and doesn't leave smudges on delicate articles. Hence the phrase "kid glove treatment", implying handling something with delicacy and tact.

so after aplitting korea into north and south (as they are know all around the world), the US will again split north korea into west/east. will it be east korea? or north east korea?