It makes sense to me that Russia is setting the tone for Turkey and Syria to cooperate openly and formally in recuperating all of Syria’s territory. Certainly, with regard to Idlib and quite likely the Usreal Kurd eastern annexed and occupied part as well.
There are several reports here talking about informal cooperation between Turkey and Syria. Most recently- December 25/2018:How Turkey, Iran and Russia will agree on eastern Syria: Cooperating in the East
It's clear in my mind that informal cooperation has been ongoing. For years now. At some point in time, the cooperation would have to made open and formal.
That said, let's get on to this latest report
Russia's option to revive Turkey's relations with Syria: Expert
Abdel Bari Atwan
Atwan in an article released on Saturday in Ray–al-Youm newspaper added that everyone who followed the press conference of President Vladimir Putin and Turkish President Recep Tayyip Erdogan in Moscow on Wednesday, after a three-hour meeting, has come to the conclusion that direct talks between Damascus and Ankara are approaching, and a joint attack by Turkey and Russia on the Tahrir al-Sham terrorist group (former Al- Nusra Front) in Idlib and its suburbs has been agreed and its zero hour is set and the implementation of agreement has been linked to days and weeks to come.A joint effort on Idlib in the works was mentioned just last week
The expert reiterated that recalling the Syria-Turkish security agreement signed in 1988 ( Adana Agreement) by Putin was remarkable, and his emphasis on the treaty could solve a lot of problems in restoring security on the southern borders of Turkey.Previously mentioned statement by Lavrov:
In 1998, with the increase in political, military and organization of the PKK group in northern Syria, as well as in the cities of Aleppo, Damascus and Al- Beqaa in Lebanon, Turkey was offered to address the case with the then-President of Hafez al-Assad of Syria to negotiate. Following the initial agreement, an agreement was signed in the city of Adana, in the presence of security and political officials of the two countries, known as the 'Adana Agreement'.
About Russia's proposal to re-engage the agreement on the negotiating table between Turkey and Syria the analyst wrote that Putin's remarks about the revival of the agreement was for the first time since the Syrian crisis began in March 2011, and perhaps this is at the top of the agenda of the Erdogan talks in Moscow, and its revival may help resolve many of the problems between Turkey and Syria and the need for the establishment of a secure zone proposed by President Donald Trump along the Turkish border at a depth of 20 kilometers inside Syria.
Lavrov "entered into this agreement, assuming certain obligations, and we proceed from the assumption that this agreement remains in force. As I understand, so do the state parties to the agreement," he added.Taken a bit further: Damascus Must Participate in Any Syrian Buffer Zone
"As for discussions about the buffer zone, the security zone, this cannot be the subject of an agreement between Russia and Turkey. This should be the subject of an agreement with the participation of the Syrian government, because ultimately the need to restore the Syrian government's control over the country's whole territory, including the zone, is clear to everyone,” Lavrov said on Friday at a press conference in Morocco.Based on all the information available here at the blog. I've no reason to believe anything other then that Turkey and Russia are in agreement with the restoration of Syria's territorial integrity. The threat to Syria's sovereignty still is, as always, the US/Israel/Kurdish/Coalition partners..
Russian minister said that both Moscow and Ankara had agreed on restoring Syria’s territorial integrity and sovereignty
Posts covering the Adana Accord....