The Syrian regime sent troops towards the Turkish border on Monday to contain Ankara's deadly offensive against the Kurds, stepping in for US forces due to begin a controversial withdrawal.
Outgunned and without US protection, the autonomous Kurds in northeastern Syria had few other options to stop the rapid advance of Turkish troops and their Syrian proxies.
Turkey wants to create a roughly 30-kilometre (20-mile) buffer zone along its border to keep Kurdish forces at bay and also to send back some of the 3.6 million Syrian refugees it hosts.
The United States and its partners, who spent years fighting alongside the Kurds against the Islamic State group in Syria before deserting them, have condemned the Turkish invasion, but their threats of sanctions have failed to stop it.
Washington says that it is planning to pull out 1,000 troops — almost the entire ground force — from Syria's north, in a move welcomed Monday by Turkish President Recep Tayyip Erdogan as "a positive approach." The chaos in the areas targeted in the six-day-old Turkish assault has already led to the escape of around 800 foreign women and children linked to IS from a Kurdish-run camp, Kurdish authorities said.
The Kurds had repeatedly warned of that scenario when Western countries refused to repatriate their IS-linked nationals and when US President Donald Trump made it clear he wanted to end the US military presence.
But Trump on Monday said the Kurds "may be releasing" IS prisoners to keep the US involved in Syria.
Wasting no time to fill the void, Moscow — already the top broker in Syria — clinched a deal between the Kurds and Damascus, whose ties had been icy since the minority threw its lot with Washington and unilaterally declared self-rule.