In fact, the operations of the regime forces backed by Russia have reached the point where the absence of a harsh reaction from Ankara would be perceived in Damascus as a weakness and a signal for further anti-Turkish activities not only in Idlib but possibly in Syria's northeast. Such inaction would adversely affect Turkey’s foreign image. This is especially true due to the fact that three out of 12 Turkish observation posts set up around the perimeter of the Idlib de-escalation zone in order to prevent the Syrian army from advancing were surrounded and blocked and could not prevent the further advance of the regime’s forces deeper into the zone.

Despite the widening differences in approaches on Idlib, it is too early to say that the Russian-Turkish partnership has collapsed. The present situation is rather more about testing its strength.

Moscow, in turn, points out the need to continue the fight against terrorist groups that have settled in Idlib, emphasizing that this does not violate the principles of the Astana and Sochi agreements, and that such operations will proceed since Ankara was unable to fulfill its own part of the 2018 Sochi memorandum under which it commited to separate the jihadis from moderate opposition groups.

This incident has become a climax of yet another Russian-Turkish crisis over the Idlib issue that Al-Monitor reported earlier. Ankara claims that the Bashar al-Assad regime does not comply with a cease-fire in the de-escalation zone and Moscow is unable to restrain the Syrian president. Some Turkish politicians say that the new surge of violence has already led to 400,000 Syrian refugees fleeing toward Turkey. This makes the authorities react increasingly harsh to events taking place at the border where hundreds of thousands of internally displaced persons (IDP) have already accumulated.

The situation in the Idlib de-escalation zone became seriously complicated Feb. 3. Turkey’s Defense Ministry reported the deaths of several Turkish troops and civilians in the Syrian province of Idlib as a result of shelling by the Syrian government forces. Turkish President Recep Tayyip Erdogan , who at the time was on a visit to Kiev, claimed that among the killed were three civilians and five soldiers. In retaliation, the Turkish artillery struck at the positions of the Syrian army in the area. The Russian Defense Ministry, in turn, said Ankara did not warn Moscow of the military activity in Idlib.

In addition, at the current stage of the military operation in Idlib, pro-government troops have reached a critical “psychological barrier” for Ankara — the M4 highway. More precisely, they are at the crossroads of the M4 and M5 highways near the city of Saraqeb. If Assad’s forces carry out military operations beyond these highways — to the north of the M4 and west of the M5 — there will no longer be any natural lines between them and the Turkish border. Ankara thus would have nothing to rely on to demarcate Greater Idlib in order to ensure the establishment of a security zone for Syrian refugees. It is important to bear in mind that the M4 route has already become a crossline between the zone of the Turkey-launched Operation Peace Spring on the one hand, and both Syrian Arab Army and Syrian Democratic Forces formations in Syria’s northeast on the other hand.

There was indeed no direct agreement that part of Idlib — north of the M4 and west of the M5 routes — should remain under the Turkish "protectorate." However, the fact that Ankara has begun to make widescale investments into Idlib as well as launched a construction project to build 10,000 houses for IDPs near the Turkish border inside Syrian territory indicates a lack of intention to allow regaining control by government forces over the entire de-escalation zone. It is significant that Germany has also provided 25 million euros ($27.5 million) in support of this project.

Therefore, as soon as the threat of a seizure of the city of Saraqib by the Assad’s regime arose, Turkey responded with a large-scale military deployment in Idlib. In just two days, on Feb. 2-3, Ankara sent five military convoys, 320 units of armored vehicles and trucks, and deployed five new checkpoints, one of which — apparently — was hit by Syrian artillery.

This has made Russia to face a choice. Moscow might be forced to take the path of unequivocal support to Damascus, hence escalate on its confrontation with Ankara, and try to force Turkish troops to withdraw from Idlib, including using the leverage of economic pressure tested during the crisis in bilateral relations in 2015-16. This will naturally lead to a complete curtailment of the Russian-Turkish partnership in all areas and will result in a forced revision of the entire Russia’s Middle East policy where cooperation with Ankara is one of the key elements.

This may also create a new reality in Syria. The United States could take advantage of Russian-Turkish tensions to finally drive a wedge between Russia and Turkey and might again provide the Turkish side with the opportunity to conduct yet another operation east of the Euphrates, for instance, in the direction of Kobani, Raqqa or Manbij.

This would expand the control zone of Operation Peace Spring to new territories. Al-Monitor explained earlier why northeast Syria is the "weak element" of the entire security architecture of Damascus. If Washington opens up airspace for the Turkish air force, the limited contingent of the regime’s forces in this region along with the Russian military police will have little chance of restraining the advancement of Turkish troops and the Turkish-backed Free Syrian Army. Ankara has already made it clear that the events in Idlib could affect Russian-Turkish cooperation in Syria's northeast when it canceled its participation in the next joint patrol. The United States has also sent a signal of support to Turkey, condemning Russia's actions in Syria.

The second option for Moscow is to take a tough stance on Damascus forcing the Syrian regime to reckon with Russia’s interests, whereas the preservation and development of strategic cooperation between Russia and Turkey is a priority issue for Russia's foreign policy. In this regard, it would be necessary to reach new agreements with Ankara on Idlib similar to the Sochi accords, including the opening of the M4/M5 routes in Idlib and joint Russian-Turkish patrols along them, similar to those held east of the Euphrates River.

In general, it would not be critical for Russia whether part of the Idlib de-escalation zone remains under the actual control of Turkey temporarily, for instance, until the end of the peace process. First, in case of Turkey's full deployment in Idlib the threat from the jihadist Hayat Tahrir al-Sham is minimized, the forces of which would be virtually blocked and subsequently neutralized by Turkish troops. Second, until Idlib has come under Assad’s rule, the Syrian regime remains dependent on Russia with its military support. As the position of Damascus strengthens, it simultaneously seeks to act more independently from Moscow. Once Idlib is under the control of the Syrian government, this independence will manifest itself in an even more dramatic fashion.

The Syrian regime, for its part, is interested in a speedy military solution to the Idlib issue, therefore it may be capable of any provocation in order to prevent a new Russian-Turkish deal on Idlib. Thereby the following cannot be ruled out: The recent incident that resulted in the death of Turkish soldiers could be a deliberate provocation of the Syrian regime’s forces to damage Turkey-Russia ties. The possibility of such a scenario was also indicated by the former head of intelligence of the Turkish General Staff, Ismail Hakki Pekin, on the HaberTurk TV channel. He noted that both the Assad regime and other countries can stand behind a provocation aimed at a clash between Russia and Trukey in the region. Thus, it is impossible to exclude a repetition of such provocations.