A fighter, second from right, of U.S-backed Syrian Manbij Military Council stands next to U.S. humvee at a U.S. troop’s outpost on a road leading to the tense front line between Syrian Manbij Mili …

A fighter, second from right, of U.S-backed Syrian Manbij Military Council stands next to U.S. humvee at a U.S. troop’s 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, Syria on March 29, 2018. The United States’ main ally in Syria on Thursday, Dec. 20, 2018, rejected President Donald Trump’s claim that Islamic State militants have been defeated and warned that the withdrawal of American troops would lead to a resurgence of the extremist group.(AP Photo/Hussein Malla, File)