my understanding is that the kurds, who can defend themselves, are withdrawing in self-restraint. they're looking for dialogue before they react. if they have to, they can try to move back in, but their decision to do so will be connected to demographic considerations and not to maximizing surface area.  

that's smart on it's face.

unfortunately, i do not believe that the syrian government is acting independently of american military command and would expect that if the nazi syrian government is moving to take control of territory, it is with american approval, and no american mediation is coming.