The fragile peace of Idlib must hold – or the confluence of global powers could lead to Syria's bloodiest slaughter yet

Violent rumblings are being heard in Idlib once again. Home to more than three million people with nowhere to flee, the last province under opposition control in Syria has endured a restless peace, one that is constantly threatened by the whims of the regime of Bashar Al Assad and his Russian sponsors.

And there are signs that they, too, are restless.

Last weekend, rebel fighters reported that violence was escalating along the edges of the demilitarised buffer zone on the borders of Idlib. They said there was an increase in mortar and rocket attacks from forces loyal to Mr Al Assad, threatening the ceasefire negotiated by Russia and Turkey, whose defence ministers met on Tuesday to discuss "urgent" issues related to the deal.

While there are some warning signs, it appears both Moscow and Damascus, as well as rebel fighters in Idlib, are largely adhering to the spirit of the agreement brokered by Turkish President Recep Tayyip Erdogan. At the moment, the conflict in Syria is largely on hold, a brief respite from nearly eight years of bloodshed.

But this is no time for complacency. The fragile status of a rebel-controlled Idlib on the Turkish border, hosting millions of displaced civilians from all over the country, and an Assad regime eager to ride the momentum of its recent triumphs and complete a military victory, are unsustainable. Russia, Iran and Turkey are due to meet again in Astana next week for further rounds of talks on the future of Syria, and Idlib in particular. The breakdown of the ceasefire without a viable peace process in place will spell disaster for the trapped and besieged.

Mr Al Assad’s forces, backed by Russian airpower and Iranian-sponsored militias, have reclaimed much of the war-torn country, forcing the rebels’ surrender in Homs, Aleppo, Daraa and the Damascene suburbs of Eastern Ghouta, after carrying out crippling sieges and atrocities. Those who survived were forcibly exiled or fled to Idlib, amid fears of never being seen again in the regime’s dungeons or being recruited into the military.

The government now controls most of the country, including north-eastern Syria, which is held by Kurdish militias backed by the US. Much of the vast northern border is held by Turkish proxies – Syrian rebels trained and backed by Ankara, who fought campaigns in the north against ISIS and the Kurdish paramilitary forces.

The September deal brokered by Mr Erdogan followed reports of an imminent campaign to reclaim Idlib, a prospect that would have sent tens of thousands of refugees fleeing into Turkey, where public opinion is now strongly in support of sending them back to Syria. But Moscow also seemed loath to pursue a military offensive that was likely to cause thousands of civilian casualties and dwarf the humanitarian catastrophes seen in Aleppo and Eastern Ghouta.

Turkey is supposed to rein in Hayat Tahrir Al Sham, the jihadist group formerly affiliated with the Al Qaeda terror network and one of the most powerful military factions in Idlib. It appears to have limited ability to do so and Russia has continued to warn of its malign influence, a potential casus belli, or cause for war. The civilians who have continued to protest against both Mr Al Assad and Hayat Tahrir Al Sham have no say in the matter, their fates of little consequence to the manoeuvring of regional and world powers.

Idlib is a confluence of the international interests that have torn apart Syria. The current status is unsustainable but the alternative is so bloody that one recoils from even imagining it – a slaughter greater than the worst crimes of Mr Al Assad’s regime, which include chemical weapons, starvation sieges, systematic bombing of hospitals and crude targeting of civilian infrastructure and rescue workers.

Western powers must make it clear that Idlib is a red line that, if not resolved peacefully, will preclude any reconstruction aid to help rebuild the country. Reconstruction funds are the only leverage western countries have after ceding much of the battleground, particularly with Russia eager to avoid a hefty bill for rebuilding the country it helped destroy.

Once a solid agreement is in place, rebel groups can take the initiative to oust Hayat Tahrir Al Sham from its strongholds in the province. The jihadists already face opposition from civilians, who regularly protest their excesses and anxious to stop their meddling in public life.

Turkish-backed rebels have also established a ground corridor into Idlib from the Kurdish-majority city of Afrin, which they invaded earlier this year. The campaign, undertaken after Turkish instigation, was concluded much more swiftly than analysts expected. The Ankara-backed group consists of about 20,000 trained fighters, now veterans of bitterly fought campaigns, who can take on Hayat Tahrir Al Sham, much like rebel groups helped oust ISIS earlier this year from Idlib and most of Aleppo.

Such a campaign would eliminate Moscow’s rationale for wanting to reclaim Idlib militarily. The unified rebel force that would control Idlib would mostly be a Turkish proxy but would represent the combined military power of the opposition in future peace negotiations, and perhaps play a role in peacekeeping in the province once a deal is reached.

For now, though, immediate disaster must be averted and the peace must hold in Idlib, or thousands more will die in Syria.