China already feels threatened by our military being in SK. Now you want to intentionally threaten them with nukes? I bet if we offered to leave SK they'd agree to reign in NK. That won't happen though because at the end of all things we are the overzealous warmongers that won't stand for our military not being positioned right outside of everybody's anus.
If we agreed to leave SK, the Chicoms would crow to the world that they defeated the United States, immediately invade SK, move their nuclear arsenal to the coastline and threaten Japan.
Do not ever think that the Chicoms would be civilized or rational or hold to any western value.