A lasting peace with the United States, does not mean they should have access to ANY American hardware, especially anything more advanced than a simple M4 carbine. They will us\e them against somebody, or sell them to to a power that shouldn't be seeing them. We gave them enough hardware during the daddy bush years. Remember when donald rumsfeld ran the cia?
No, of course they shouldn't have them, but it's to late for that now since they won't agree to give them back and it was already decided to abandon them there - the only thing to do going forward is let them have their own way in their own country, that is if you want peace. If you don't want peace, then keep trying to interfere in other countries such as policing the world etc, other countries really hate that.
Losing those weapons are already a loss, why risk even bigger losses by not writing it all off?