Syrian government forces have wasted no time in taking advantage of the abrupt U.S. withdrawal from that country.
State television showed what it said was President Bashar al-Assad's troops deploying to several towns, deep inside the Kurdish-held territory south of the Turkish border.
Kurdish officials say their new alliance with Damascus is a quote, "emergency measure" to help fend off the Turkish assault.
And comes after what they're calling a 'betrayal' of their former ally in Washington.
The Syrian government deployment is being heralded as a major victory for Assad, but also his principal ally: Russian President Vladimir Putin.
Assad will hope to regain a foothold in a region formerly beyond his control.
And, after eight years of civil war, regain control of across all of Syria.
Washington announced on Sunday that was pulling out its entire force of the thousand or so soldiers who'd fought alongside the Kurds against Islamic State since 2014.
Turkey aims neutralize the Kurdish YPG militia, the leading component of the Syrian Democratic Forces coalition - which Turkey views as a terrorist group.
But the assault has also raised fears it could allow Islamic State fighters in Syria to escape Kurdish-run prisons and regroup.
At least a hundred foreigners affiliated with Islamic State were said to have escaped a guarded camp over the weekend.
President Trump, providing no evidence, tweeted Monday that the Kurds might be releasing Islamic State prisoners deliberately to lure back the U.S.