It seems to me that what is coming is a de facto partition of Syria. I doubt if there is an actual understanding or agreement on the subject but the actions of the players indicate that they comprehend what the outcome will be if present trends and actions continue.
IMO the SAG should have re-captured Idlib Province in the period immediately following their victory at Aleppo. The jihadist enemy was then on the run, disorganized and demoralized by defeat. The correlation of forces was very much in the government's favor. This did not happen.
Instead the SAG went east from Aleppo City to secure water and electric energy supplies for the re-construction of Aleppo. Success led to further and further exploitation to the east and the opportunity was lost to re-take the province. Whether or not the government still has the means or the will, or enough Russian support to re-capture the province is debatable. The Turks are busy conquering the Afrin district. Can anyone seriously doubt that they will succeed in the end? When that happens we will see an effective barrier against government control established farther south by Turkish forces closing up on their "observation posts" in Idlib Province. These OPs are IMO positioned to impede the SAA.
On the line of the Euphrates River a de facto frontier has already emerged between government control to the south and US/SDF to the north and east of the stream. Evidently the US intends to discourage a SAG/SDF reconciliation in the hope of maintaining the dream of eventual destruction of the Damascus government. The enclave around al-Tanf on the Jordanian border is yet further indication of American desire to impeded and embarrass SAG efforts to re-consolidate power. I think the US will cling to that enclave "until the last dog dies." (American modismo). What will be the administrative center of the US protectorate on the other side of the Euphrates? Will it be the former IS capital in the damaged city of Raqqa? Will the denizens of that be-deviled place see a proliferation of KFC and McDonald's. If so, will the franchisees be Chinese? The US is leaving Iraq, diverting forces to the unwinnable war in Afghanistan. Iraqi politics will encourage that departure. When that happens the US will be in possession of a landlocked territory in eastern Syria that is inhabited by people who don't like us very much even if necessity has made them our allies.
The SAG has massed a significant percentage of its mobile forces to capture the jihadi stronghold of East Ghouta. The preparatory fires have naturally excited the jihadis who hold the area and their media allies in the US and Europe. I expect that this size force will do an adequate job of jihadi cleansing in the near future and then move on to browner pastures. With the prospect of having to govern a rump Syria under Russian, Iranian and Chinese tutelage, the SAG will probably move to clean up the several rebel held pockets aligned north to south from the Jordanian border to north of Hama City.
Will the Syrian government acknowledge the loss of its territories? They will not. pl