Russia and Turkey have come to an agreement over Syria's last rebel stronghold, Idlib. Following their latest round of talks in Sochi, Russia, on Sept. 17, Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan announced their deal to set up a 15- to 20-kilometer (9.3- to 12.4-mile) jointly patrolled demilitarized zone around the province by mid-October. The agreement, which will prevent Russian-backed loyalist forces from launching a major offensive to reclaim Idlib from the rebels, stands to ease tensions between Russia and Turkey. Nevertheless, the standoff over Idlib is far from resolved, and numerous obstacles remain that could undermine the deal.
The fate of Idlib, the last rebel stronghold in the Syrian civil war, will help determine the future of the conflict. Not only could Idlib make or break Turkey's relationship with Russia, but it could also draw in external powers and drag the war beyond Syria's borders.
Reaching a Compromise
Russia agreed to the deal out of a desire to preserve its relationship with Turkey. The Turkish government opposed the Russian-backed operation on Idlib, which would have deprived it of a buffer zone in northern Syria while also driving millions of Syrian refugees into its territory. To try to avert the operation, Ankara reinforced its 12 observation posts in and around Idlib and promised its rebel allies in the region more supplies and support. Russia still could have maintained its backing for the Syrian military attacks on the province, striving to avoid a direct confrontation with Turkish forces by steering clear of their observation posts. But given the high risk of accidental strikes on Turkish troops — and the damage they would cause relations with Turkey — Moscow instead opted for a compromise with Ankara. By avoiding significant offensive operations in Idlib, moreover, Russia reduced the chances that the Syrian government would carry out another chemical attack on Idlib's rebel forces, thereby warding off dangerous strikes from the United States and its allies.
Though the agreement accomplished Ankara's goal of deterring a major assault on Idlib, it is not without its costs for Turkey. Turkey, for instance, has openly promised to work to drive out rebel forces from the demilitarized zone around Idlib as part of the deal. In addition, it has probably assured Moscow privately that it would do more to crack down on the extremist groups still operating in the province, such as Hayat Tahrir al-Sham and the Turkistan Islamic Party in Syria. These groups and their regional affiliates not only include many Chechen and Uighur militants among their ranks — a source of concern for Russia and China, respectively — but they also have spearheaded attacks against Russian forces in Syria. In several strikes, for example, they used drones to drop rudimentary explosives onto the Russian air base at Latakia.
The extremist groups' reaction to the deal will pose the most immediate obstacle to its success. Having maintained their ties with Turkey, jihadist organizations like Hayat Tahrir al-Sham and the Turkistan Islamic Party will face considerable pressure from Ankara to withdraw from Idlib. Their cooperation is hardly guaranteed, however. The groups have long been wary of Turkey's intentions and are aware of its efforts to set up a rebel coalition, the National Front for Liberation, to balance and eventually replace them in the fight. Furthermore, giving up front-line positions and quietly withdrawing from the demilitarized zone would contradict their hard-line ideological stance in the fight against the Syrian government. By compromising their beliefs in this way, the groups could risk further splintering and lose recruits to al Qaeda affiliate Hurras al-Deen or to lingering Islamic State cells in the region.
On the other side of the zone, Russia's allies Iran and the Syrian government will also challenge the deal. Tehran and Damascus have been keen to get Russia's backing for a full-scale offensive on Idlib and will not be pleased with the agreement, though they may publicly endorse it. Motivated to destroy the deal and weaken Russia's relationship with Turkey, the Syrian government could, with Iran's help, start skirmishes with rebel forces or even launch its own attacks in the region under the pretense of responding to strikes by the extremist groups there. All these constraints mean that violence and instability will continue to grip the region, even without the prospect of a major offensive on Idlib.