Look, I will acknowledge right up front that I am not particularly knowledgeable about this area of the world. So please bear that in mind with the following thought:
Given that Syria is a complete mess right now
Given that Turkey has an ongoing issue with Kurdish groups
What if we (the collective world we) carved out a chunk of northwestern Syria and allowed the Kurds to build a state there? I am thinking that we might be able to negotiate with both the Kurds and Turkey that such a state would be given friendly status with Turkey and the west, and in return the Kurds would relinquish any claims to Turkish territory as part of a Kurdistan. Ethnic (?) Kurds would be allowed to either stay in Turkey as willing Turks, or migrate to the newly formed Kurdistan and take part in the building of a nation.
Would this/could this accomplish several things at once? If utterly stupid, please explain…