The SAA needs to clean up Idlib etc before targeting the Kurds for sedition and secession. The Americans will use this time to get ahead of the curve and establish "new facts" while the enemy is pre-occupied. The Russians could care less (figuratively) but obviously Assad and Iran do not - it will be them who really decide what the future of SDF held areas will look like and they'll have to strategize extremely well cause Russia will not back them up except token diplomacy. intelligence sharing + fodder equipment.
Russia has come to accept these kinds of deals with the U.S, as it's not their territory - thus shouldn't be relied on. Examples everywhere.
Syrian/Iranian leadership will have to weight the cost of going full takeover Vietnamese style. A lot of blood, a lot of effort, and costs. Operating without an "air force" and being vulnerable to american air power is going to be bloody. It will have to be a multifaceted offensive, not just on the SDF, but American forces all over the Middle East in a sensible fashion (targeted terrorism) that "attempts" to prevent full blown war.
The other option is simple: accept the partition. The Americans have made the cost clear. Others only need to weight whether they're willing to pay the cost. You never know, most of it could be bluff, but they've made sure, several times, to clear any illusions of bluff with the targeted airstrikes. Thus, again, to war or to capitulate.
Last edited by ATLASCUB on Mon Jan 08, 2018 8:31 am; edited 1 time in total