Turkey-backed rebels clash with U.S.-supported Syrian Kurds

ANKARA, TURKEY— Turkey sent more tanks into northern Syria on Thursday and gave Syrian Kurdish forces a week to scale back their presence near the Turkish border, a day after it launched a U.S.-backed cross-border incursion to establish a frontier zone free of the Daesh and Kurdish rebels.

Skirmishes broke out between Turkish-backed Syrian rebels and the U.S.-backed Kurdish fighters, raising the potential for an all-out confrontation between the two American allies that would also jeopardize the fight against Daesh (also known as ISIS or ISIL) in the volatile area.

Turkey’s incursion Wednesday to capture the town of Jarablus was a dramatic escalation of Turkey’s role in Syria’s war and adds yet another powerhouse force on the ground in an already complicated conflict.

But Ankara’s objective went beyond fighting extremists. Turkey is also aiming to contain the expansion by Syria’s Kurds, who have used the fight against Daesh and the chaos of Syria’s civil war to seize nearly the entire stretch of territory along Syria’s northern border with Turkey.

Above all, Ankara seeks to avoid Kurdish forces linking up their strongholds along the border. The U.S. has backed its NATO ally, sending a warning to the Syrian Kurds with whom it has partnered in the fight against Daesh to stay east of the Euphrates River.

Chris Kozak, a Syria researcher, said an open confrontation between Turkey and the Kurds in Syria would undo much of the progress made working with the Kurdish forces against Daesh in Syria.