A RUSSIAN-BACKED offensive to retake Idlib, the last big rebel-held stronghold in Syria, seemed imminent only a few days ago. Russia had expanded its fleet of warships off the Syrian coast. Regime troops were massing at the perimeter of the province. Russian jets had begun to bomb rebel targets and destroy hospitals. UN officials were warning of the biggest humanitarian catastrophe of the century as one of the war’s biggest battles loomed.
Now the offensive is on hold. On September 17th Turkey and Russia, which back opposing sides in the war, agreed to establish a buffer zone in Idlib that separates regime forces from their rebel adversaries. To keep the peace, Turkish and Russian military police will patrol the nine to 12-mile wide strip. Rebel forces in the demilitarised zone will have to give up their heavy weapons by October 10th. The jihadists of Hayat Tahrir al-Sham (HTS), the most potent anti-government force in the province, which is linked to al-Qaeda, will also have to withdraw completely.
Much can go wrong. The deal’s success hinges on the withdrawal of HTS from the buffer zone. Should the group refuse Turkey’s efforts to persuade them, Russia would feel justified in backing a full-scale assault. The regime of President Bashar al-Assad may have little choice but to bow to the terms agreed by its Russian patron. But it has long said it wants to take back the entire country, and finally crush the revolt against its rule. It fears that Turkey is reinforcing its troop presence and, as in Hatay province, another piece of Syrian territory Turkey hived off in the 1930s, may never leave. Mr Assad might have an interest in stoking infighting among rebel factions to prevent Turkey from consolidating its hold.
The deal also underscores the danger of leaving Syria’s fate in the hands of conflicting foreign powers. Hours after sealing the Idlib deal with Turkey, Israel carried out another strike on a Syrian military installation. The attack looked routine. Israel strikes on average once a week. This time, though, the target was unusually close to Russia’s main airbase, Khmeimim, on the Syrian coast. And when Syrian air-defence batteries responded with a salvo of missiles, they shot down a Russian spy-plane, flying over the Mediterranean, with the loss of 15 crew on board.
Russia’s defence ministry initially reacted angrily. Israel, it said, had “intentionally created a dangerous situation.” Israel’s deputy ambassador in Moscow was summoned in protest. Hours later, however, President Vladimir Putin, sounded a more conciliatory tone. The aircraft, he said, had been downed in “a chain of tragic circumstances”, not by Israel. That leaves Russia’s “deconfliction” agreement with Israel intact. Israel will not interfere with Russia’s revival of the regime in Syria, and Russia will continue to allow Israel a more-or-less free rein to go after targets linked to Iran and its Lebanese proxy, Hizbullah.
Nevertheless, Russia’s success in maintaining a balance between Israeli and Iranian interests since its intervention in Syria three years ago is increasingly under strain. With jets from at least six countries—Israel, Russia, Syria, Turkey, Britain and America—regularly in the skies over Syria, the risk of mistakes or miscalculations that lead to further escalation are just a trigger-pull away.