Sooner or later, some force is going to be required to intervene and disarm the NORKs.
As I've stated before in this forum, the best way to do this would be to make a "grand bargain" with China:
- You disarm NK and prepare it for a reunification with the South
- We'll agree to keep a unified Korea permanently de-nuclearized
- In return, we'll step out of the way and let you take Taiwan back.
Taiwan in exchange for North Korea.
Sounds "good enough" to me.