WASHINGTON — Defense Secretary Mark T. Esper said Sunday that President Trump ordered a withdrawal of American forces from northern Syria, a decision that will effectively cede control of the area to the Syrian government and Russia, and could allow a resurgence of the Islamic State.
Mr. Esper, appearing on both Fox News and CBS News, said that American troops, mostly Special Operations forces, would move south but not leave the country in the face of Turkey’s incursion into the section of Syria controlled by Kurdish forces, a group of fighters trained and backed by the United States government.
The Pentagon has slow-walked previous orders by Mr. Trump to evacuate from Syria, to protect its Kurdish partners and hold the ground it took back from the Islamic State. But Mr. Esper’s comments Sunday indicated that this time Mr. Trump’s drawdown order was being acted on with haste.
The bulk of the roughly 1,000 troops in Syria are positioned in the northeastern part of the country, and the new orders will push those troops further south. Military officials said plans remained fluid, and it was not clear how far the troops would withdraw to. But in any case, the implications were clear: American forces will not be coming to the aid of their Kurdish allies in the face of the Turkish-backed offensive.
Appearing on “Fox News Sunday,” Mr. Esper defended the planned withdrawal of what he said was “less than 1,000 troops” as prioritizing the safety of American soldiers in the crisis, and he said the United States would ultimately have been unable to deter Turkey from invading Syria.
“Fifty service members are not going to stop a Turkish advance,” Mr. Esper said, referring to the “trip wire” force along the Turkish border that Mr. Trump ordered removed last week. “The U.S. doesn’t have the forces on hand to stop an invasion of Turkey that is 15,000 strong.”
Mr. Esper said the Pentagon expected Turkish forces to annex even more territory than originally estimated. He also confirmed that the commander of the Kurdish-led Syrian Democratic Forces was “cutting a deal” with Russian and Syrian government forces who are now heading north to fight back against the Turkish offensive.
Throughout the fight with the Islamic State that began in 2014, the Kurdish forces proved to be America’s most able partners. But Turkey has long viewed those forces as an offshoot of what it and the United States consider a terrorist group it has long battled inside its borders and throughout the region.
The Kurdish forces were key to breaking the Islamic State’s control of territory in Syria, effectively destroying its self-proclaimed caliphate. Despite Mr. Trump’s claim that the Islamic State is defeated, the fighters remain an effective insurgent force in Syria and Iraq. If the Turkish incursion into Syria breaks the power of the Kurdish force, some military officials believe the Islamic State could once again find lawless safe havens from which to rebuild.
American military forces pulled out of Ain Issa, a Syrian town north of the Islamic State’s former self-declared capital of Raqqa, on Sunday morning after an advance of the Free Syrian Army, a rebel group backed by Turkey, according to American military officials.
The remaining Special Operations forces are working out of about a dozen bases or outposts in northeastern Syria. One of the most important of those is Manbij, where nearly 200 American forces are based. That base is the most likely to be evacuated next.
Turkish officials have long objected to Kurdish control of Manbij. Ankara has repeatedly said it wants Kurdish forces to withdraw from Manbij, and give control to its Syrian Arab allies.
The United States also maintains a small contingent of troops at the Al-Tanf base in south-central Syria, as a deterrent to Iranian movements in that region. It was unclear whether the withdrawal order affects that post, which American officials have said in the past would be the last United States presence in the country to be withdrawn.
Defense officials emphasized that their plans for Syria remained fluid. During the next couple of days, American commanders in the region and at the Pentagon will assess options on which forces should withdraw, in which order and where. Some may withdraw to Iraq or Jordan, and others could go back to the United States or Europe. The Air Force will continue to provide air cover for the military troops that are withdrawing.
The withdrawal from northeastern Syria is expected to be complete perhaps as early as the end of October, a military official said. But the pace of the withdrawal will depend on how quickly Turkish-backed forces advance.
American forces will try to avoid contact with the Turkish-backed forces, but the military official warned they will defend themselves if attacked.