It's Syrian land that happens to also be traditional Kurdish majority land. My recommendation would be to let Assad's Regime and the Northern Federation work it out for themselves. They will find that the best "deal" for both will be the one that is easiest to administer and that there is no them against us. That discussion is for later and IMHO best left to the Syrians.
For the moment, Turkey is trying to extend its permanent Al Qaeda controlled buffer from Idlib to Jarabulas through Afrin and (if the US departs) on to the Iraq border.
