In this March 29, 2018 file photo, a fighter, second from right, of the US-backed Syrian Manbij Military Council is parked next to US humvee at a US troop outpost on a road leading to the tense front line between Syrian Manbij Military Council fighters and Turkish-backed fighters, at Halawanji village, north of Manbij town, Syria. (AP Photo/Hussein Malla, File)