This article is very speculative, but it provides a potential model for post-civil war Syria. As the article also mentions however, the situation in Syria is still not ripe for any resolution:
“To find common purpose with Russia, Washington should keep in mind the Bosnia model, devised to end the fierce Balkan conflicts in the 1990s. In that 1995 agreement, a weak central government was set up to oversee three largely autonomous zones.
In similar fashion, a future Syria could be a confederation of several sectors: one largely Alawite (Assad’s own sect), spread along the Mediterranean coast; another Kurdish, along the north and northeast corridors near the Turkish border; a third primarily Druse, in the southwest; a fourth largely made up of Sunni Muslims; and then a central zone of intermixed groups in the country’s main population belt from Damascus to Aleppo.”