The arrival of Syrian government forces in Manbij, at the behest of the Kurdish People's Protection Units (YPG), marks a striking turnaround in Syria's years-long war.
As is customary in this bitter and complex conflict, there are several moving parts.
Turkey, which this year invaded Kurdish-held Afrin, has been amassing troops around the north Syrian city of Manbij to fight the US-backed YPG, which it considers to be a terrorist group. And US President Donald Trump’s decision to withdraw all 2,000 American troops from Syria this month has put the Kurdish militia – which fought bravely against ISIS – in the firing line of a Turkish administration that cares little about the pleas of its allies. With the robust support of Russia, the Syrian regime has been steadily advancing across the country, making Manbij the latest in a string of towns and cities where the Syrian flag flies once again after years of absence. With Russian-backed Syrian forces encircling Manbij, a Turkish invasion looks unlikely and, as the uprisings against president Bashar Al Assad fizzle out, the Kurds have acted pragmatically.
But this is no ordinary turn of events. It amounts to a US partner calling on an enemy of America to protect it from another US ally, Turkey.
The situation on the ground remains fluid, so long-term predictions carry little value. Nonetheless, with Mr Al Assad looking victorious, ISIS severely depleted, and the US withdrawing, a new era is under way in Syria’s war. It does not mark the beginning of the end, but rather the end of the beginning.
What is sure to follow is a struggle for the spoils of a nation scarred by conflict. Russia, to whom Mr Al Assad is grateful for his survival, will profit greatly. But with the Syrian president’s immediate role guaranteed, the world must rally to ensure Mr Al Assad does not curry favour with Tehran.
With American military and diplomatic influence waning, that task now falls to Arab states. That is why the UAE this week re-opened its embassy in Damascus – not to exculpate Mr Al Assad but to ensure Arab voices help to shape Syria's future. That, too, is why the Arab League is considering re-admitting Damascus after expelling the country in 2011.
Meanwhile, daily life remains intolerable for millions of innocent Syrians. Fierce clashes between remaining ISIS militants and US-backed Syrian Democratic Forces last week left scores dead on both sides. And on Wednesday, an Israeli official confirmed a series of air strikes targeting Iranian assets, had their origins in Tel Aviv. The YPG and Manbij are early casualties of Mr Trump’s troop withdrawal.
As the Syrian regime’s power stretches over the scorched earth, where half a million have died, we have reached a pivotal moment. Mr Al Assad will be tolerated, but the Iranian threat cannot be. Curbing it diplomatically might now fall to those who Tehran’s activities endanger most in the Arab world.