NK v SK conflict is not that different to India v Pakistan. The difference is... there are US troops sitting on the border of NK/SK, so agression between those to parties involves the US.
So who is the destabilising force in the region? I'm pretty sure "stability" isn't the goal (for the US) it's "Democracy".
The difference is so much greater than that. North Korea is a completely irrational regime. It is lost in a fantasy world. Pakistan, though it's stability is questionable, is not off on some bizarre ideological island. It's not as if the Pakistani government could convince it's citizens of the sort of nonsense the North Korean government does.
So who is the destabilising force in the region? I'm pretty sure "stability" isn't the goal (for the US) it's "Democracy".