Since the Kurdish authorities asked for the help of President Bashar al-Assad's government, for the first time since the government lost control of the region several years ago, thousands of Syrian troops have been flooded into northern Syria.
But Syrian government forces have kept their distance from the border region near Ras al-Ain, where Kurdish forces are fighting alone. Instead, government forces have occupied other strategic positions, such as the western cities of Manbij, to reduce pressure on the Kurdish fighters at the front.
The last-minute alliance is a costly burden for the Kurdish authorities, which virtually give up self-government.
The Syrian-Kurdish militias established a self-governing system in northern Syria in 201
The fighters were largely expanding their territory after joining forces with a United States-led international military coalition to push the Islamic State out of the area.
After the Kurdish-led fighters conquered IS territory, they took responsibility for its leadership and eventually controlled roughly a quarter of the Syrian landmass. They also guarded thousands of ISIS fighters and their families, hundreds of whom fled a Ras al-Ain detention center after Turkish troops bombed the area.
The control of the Kurds over the country in Syria angered Turkey. because the militia is an offshoot of a guerrilla group that stood up for decades against the Turkish state. Turkey has long pressured the United States to abandon its alliance with Kurdish fighters so that Turkish troops can invade Syria and force Kurds from the border region near the border of Ras al-Ain, the city in the center of the fighting on the Friday. But that changed last week, when Mr Trump suddenly decided to withdraw troops – first from that particular area and later from all over northern Syria.
Carlotta Gall reported from Ceylanpinar and Patrick Kingsley from Istanbul.