ISTANBUL — As the chief backer of Syria’s embattled opposition, Turkey now faces a perilous task. It must disarm its rebel allies in Syria’s Idlib province, under a new agreement with Russia, and eliminate the hardcore jihadists in their midst.
If not, Syrian and allied Russian forces have threatened an all-out assault to retake the territory — a battle that aid agencies say would be the most devastating of the war. The cost to Turkey itself could be immense.
Turkish President Recep Tayyip Erdogan and his Russian counterpart, Vladimir Putin, announced an 11th-hour plan on Sept. 17 to avert the bloodshed, giving Turkey more time to persuade its proxies to disarm. Under the pact, Turkish and Russian troops would patrol a demilitarized zone — about nine to 12 miles deep and free of extremists and heavy weapons — and eventually open Idlib’s highways to traffic.
Idlib’s roughly 3 million residents may have a reprieve, but the fate of the province remains uncertain. It represents the opposition’s final stronghold in Syria after nearly eight years of conflict, and the stakes for Turkey are high because it borders the province and has troops stationed there.
“Turkey’s interests are enmeshed in Idlib’s in a way that makes Turkey exceptionally vulnerable,” said Sam Heller, a Beirut-based analyst at the International Crisis Group.
Turkey projects influence by helping keep Idlib in opposition hands, and this, Heller said, “secures Turkey more of a foothold in the running negotiations for Syria’s political future.” Turkey’s presence in the province also forces Russia, which is the dominant military power in Syria, to take heed of Ankara’s interests.
But Turkey is also dangerously exposed. “There are genuinely disastrous implications for Turkey if Idlib were to collapse,” Heller said.
A battle for Idlib could send millions of new refugees toward the border, which officials fear would stir social and political upheaval inside Turkey.
More than 3 million Syrian refugees already live in Turkey, and while “there are very few issues that unite most Turks, one of them is opposition to Syrian refugees,” said Soner Cagaptay, author of “The New Sultan: Erdogan and the Crisis of Modern Turkey.”
As rumors of an offensive swirled in recent weeks, more than 30,000 people fled to different parts of Idlib, the United Nations said. Some of them returned home recently.
The Turkish government is also worried that an influx of displaced Syrians could be infiltrated by hardcore militants, leaving Turkish towns and cities — and even countries in Europe — vulnerable to extremist attacks.
There is the risk that “armed radical groups that resent Ankara’s mediation efforts will punish Turkey by launching terrorist attacks in Turkey,” Metin Gurcan, a former Turkish military adviser, wrote in a column for the online news portal Al-Monitor.
Turkey has long supported anti-government rebels in Syria and invested heavily in Idlib province with troops and military equipment, seeking to separate al-Qaeda-linked fighters from the ranks of more mainstream rebels.
Turkey has recently reinforced its observation posts in Idlib, established as part of an earlier agreement with Russia and Iran, deploying tanks, commandos and multiple rocket-launching systems, Gurcan said. The aim is to demonstrate Turkey’s commitment to Idlib and enhance its defense against militant attacks, Gurcan said.
The agreement reached last week, while short on specifics, “has bought more time so that diplomats, politicians, can still do their job and avert what still may be very bad developments for civilians,” a senior United Nations official, Jan Egeland, told reporters in Geneva.
“This is not a peace deal, this is an ‘aversion of whole-scale war’ deal,” he said. But the agreement halted what “seemed to be a relentless countdown” to conflict, he said, even if the message U.N. officials were receiving from both Turkey and Russia is that “we are still working, ourselves, on the details.”
Turkey now faces a tight — and some say unrealistic — deadline to demobilize allied rebels and persuade al-Qaeda-linked groups to give up the fight.
The document signed by Putin and Erdogan imposes an Oct. 10 deadline for all heavy weapons — including tanks, mortars and artillery systems — to be removed from the horseshoe-shaped zone. And by Oct. 15, all designated terrorist groups must be cleared from the area, including Hayat Tahrir al-Sham (HTS), a former al-Qaeda affiliate and the largest armed faction in Idlib.
The agreement “puts hard dates” on Turkey to demobilize its partners and “handle HTS,” Aaron Stein, a senior fellow at the Atlantic Council’s Rafik Hariri Center for the Middle East, wrote on Twitter. “The dates come fast.”
HTS, which has about 10,000 fighters, called the agreement an attempt to “weaken the mujahideen” by disarming their ranks.
“Where will the terrorists from Idlib go? What are they going to do there?” wrote veteran Turkish foreign affairs columnist Sami Kohen, questioning the deal’s wisdom in Turkey’s Milliyet newspaper Friday.
“Will they give up their actions and agree to be integrated into the Syrian society?” Kohen asked. “A more pessimistic possibility is that the terrorist groups refuse to abandon their weapons and positions and resist the Turkish soldiers.”
If Turkey fails to persuade its rebel allies to comply with the deal, they could become even more belligerent.
A spokesman for the Turkey-backed National Liberation Front, an opposition umbrella coalition in Idlib, said rebel groups remained on “high alert.”
“I don’t think that Turkey will give anything” to Russia in negotiations, the spokesman, Capt. Naji Mustafa, said. “Turkey has been supportive of the Syrian revolution since the beginning.”
But, he added, “Turkey knows that if a military operation took place, the people in Idlib would not go back to areas under regime control. They will try to go to Turkey. And Turkey does not want that.”
Zakaria Zakaria contributed to this report.