I have doubts on both sides being able to offer up the concessions in a way the other side can accept
Usa will be wanting full denuclearization, but over what timeline, which inspections, what degree of access, and what stage gates?
DPRK want usa troops out of south korea, but over what timeline, is it perm only or visiting troops/vessels too, will sth korea and japan agree, and will no more joint exercises be accepted?
The devil will be in the detail on this. DoD dont want to leave the peninsula, and are genuinely concerned trump may agree to a usa exit.
Fwiw i have no issue with a staged usa troop withdrawal tied with staged denuclearization. I know im in a minority however