MANAMA, Bahrain — United States troops have resumed large-scale counterterrorism missions against the Islamic State in northern Syria, military officials say, nearly two months after President Trump’s abrupt order to withdraw American troops opened the way for a bloody Turkish cross-border offensive.
American-backed operations against ISIS fighters in the area effectively ground to a halt for weeks despite warnings from intelligence analysts that Islamic State militants were beginning to make a comeback from Syrian desert redoubts even though their leader, Abu Bakr al-Baghdadi, had been killed during an American raid on Oct. 26.
On Friday, American soldiers and hundreds of Syrian Kurdish fighters — the same local allies the Trump administration abandoned to fend for themselves against the Turkish advance last month — reunited to conduct what the Pentagon said was a large-scale mission to kill and capture ISIS fighters in Deir al-Zour province, about 120 miles south of the Turkish border.
“Over the next days and weeks, the pace will pick back up against remnants of ISIS,” Gen. Kenneth F. McKenzie, the commander of the military’s Central Command, told reporters on the sidelines of the Manama Dialogue security conference in Bahrain on Saturday.
The resumption of extensive counterterrorism operations capped a tumultuous two months in which many of the nearly 1,000 American troops in northeastern Syria flew or drove out of the country under Mr. Trump’s withdrawal order. Separately, several hundred other troops, some with armored Bradley fighting vehicles, arrived from Iraq and Kuwait under a subsequent order from Mr. Trump to protect Syria’s eastern oil fields from ISIS, as well as from the Syrian government and its Russian partners.
When the dust settles on all of the troop movements, General McKenzie said he would have about 500 American forces, or half of what he had before Mr. Trump’s directives, operating in an area east of the Euphrates River and Deir al-Zour, north to al-Hasakah and into Syria’s far northeast along the border with Iraq.
American commandos and their Syrian Kurdish partners conducted some low-level missions after the withdrawal order. But now that Americans and Kurds had regrouped their joint operations in the much smaller area, General McKenzie said, they could resume bigger missions against ISIS.
“What we’re talking about are the pockets of people who represent the wreckage that followed in the wake of the caliphate,” General McKenzie said in describing what was left of ISIS’s religious state that at its peak was the size of Britain. “They still have the power to injure, still have the power to cause violence.”
The operation on Friday in Deir al-Zour province against several ISIS compounds killed or wounded “multiple” ISIS fighters and resulted in the capture of more than a dozen others, according to a statement from the American military coalition in Baghdad, which oversees the operations in Syria.
After the American withdrawal from the border, Vice President Mike Pence reached a deal with President Recep Tayyip Erdogan that accepted a Turkish military presence in a broad part of northern Syria in exchange for a cease-fire. The deal amounted to a near-total victory for Mr. Erdogan, as thousands of Syrian Kurds were forced to flee south, often battling with ill-disciplined Turkish proxy forces as they went.
The United States considers the Syrian Kurds a pivotal partner in the fight on the ground against ISIS, but Turkey views them as terrorists, a distinction that has repeatedly put Washington in a difficult position.
Syrian Kurds who counted the United States as a friend and an ally accused Washington of betrayal immediately after the withdrawal from the border and the Turkish offensive. Army Green Berets who had fought alongside the Kurds and praised them for their valor said they felt ashamed at how the United States had treated the Kurds.
General McKenzie insisted that relations between the two sides were now “pretty good.” He did not say, however, how long American troops would stay in northern Syria. “We don’t have an end date,” he said twice during an interview with reporters on Saturday.
With a mercurial president who has twice in 10 months ordered all American troops out of Syria immediately — only to reverse himself twice after aides implored him to reconsider — other senior commanders say the Pentagon has to be ready for another no-notice message on Twitter that American troops are leaving, oil or not.
It was a message that Mr. Pence, on an unannounced pre-Thanksgiving visit to Iraq, repeated on Saturday even as he sought to reinforce the administration’s support for the Kurds and the mission of protecting the oil fields. “President Trump is always going to look for opportunities to bring our troops home and to take these men and women out of harm’s way,” Mr. Pence said.
The immediate fight may be on again against ISIS, but General McKenzie said that protecting the oil fields might ultimately draw a larger challenge from Syrian Army troops west of the Euphrates. “I’d expect at some point the regime will come forward to that ground,” General McKenzie said in a separate interview before the security conference.
The last time pro-Syrian government forces threatened American troops near the oil fields, in February 2018, the United States unleashed an artillery and aerial bombardment that left 200 to 300 of the attacking fighters dead. Most of that American air power is still nearby.
At the security conference in Manama on Saturday, several top European and Middle Eastern officials urged their counterparts to continue applying unrelenting pressure on ISIS, which is also called Daesh, in northern Syria.
“ISIS leaders have been killed and territory reclaimed, but the profound crisis of governance that made Daesh’s emergence possible is still there,” said France’s minister of armed forces, Florence Parly. “France’s aircraft will continue to strike relentlessly, and French forces will continue to train and equip partner forces.”
Ayman Safadi, Jordan’s minister of foreign affairs, added that ISIS also posed “an ideological challenge with which we are also having to deal and which, frankly, only us in the region can take the lead in this fight.”
“We need to expose terrorists for the thugs that they are,” he added.