But at least eight U.S. service members who served with Kurdish forces in Syria and Iraq expressed disgust in interviews with The Washington Post about the rapid U.S. changes and the lack of a clear plan to prevent a crisis. Many of them, speaking on the condition of anonymity because of the sensitivity of the issue, doubted that Turkish forces would have launched an assault into northern Syria if the White House had not said it would stand aside.

“I can’t even look at the atrocities,” an Army officer who served in Syria last year said of videos posted online of Turkish-backed fighters executing Kurdish civilians. “The ISIS mission is going to stop, ISIS is going to have a resurgence, and we’re going to have to go back in five years and do it all again.”

He added that while he was in the Middle East, military officials at the Pentagon sometimes discussed with officers in the field how they could craft a compelling case for Trump to stay longer while a thoughtful exit strategy could be designed.

“I remember hearing, ‘How are we going to phrase terms to convince Trump not to go off a cliff?’ ” the officer said. “It’s like, ‘How do you steer him to the right decision and not where he wants to go?’”