The recapture of an Islamic State stronghold in Syria will serve as a model for future U.S.-backed operations there, U.S. officials said, as the Pentagon lays plans for supporting a march by allied forces toward Raqqa, the militant capital.
Late last week, fighters affiliated with the Syrian Democratic Forces (SDF), a U.S.-supported group that includes Kurdish militias and local Arab groups, regained control of the city of Manbij, which sits near the Turkish border and had been a key logistics point for the Islamic State.
U.S. officials, who spoke on the condition of anonymity because they were not authorized to discuss the campaign publicly, said the Manbij offensive illustrated the value of the small force of U.S. Special Operations troops now on the ground in Syria, as they coordinated U.S. airstrikes and advised Syrian forces during an intense urban fight.
“Our operating concept has been validated,” said a senior defense official. “Utilizing local forces and our own Special Operations forces, partnered with overwhelming coalition air power, and enough time — the Islamic State really doesn’t have an answer to it.”
Manbij had been a significant military objective for a number of reasons, including its role as a hub for foreign fighters coming into Syria from Turkey, many of whom would travel from there to Raqqa, some 90 miles to the southeast.
They also believe the city was instrumental in the Islamic State’s effort to mount external attacks against the West, saying that militants used the city as a point for pushing experienced fighters toward Europe. In recent weeks, American officials have been combing through large amounts of digital data that U.S.-allied forces seized around Manbij — information that has already provided insight into the group’s recruitment operations.
The Islamic State’s defeat in Manbij was welcome news in a conflict that has confounded U.S. policymakers and created dangerous spillover effects across the region. Since late last year, U.S.-backed forces also have captured the town of Shadadi and a strategic dam from the militants, but neither of those areas was as fiercely defended as Manbij.
Those developments were seen as an affirmation of President Obama’s decision to send a small team of Special Operations troops into Syria — a move that deepened U.S. involvement and exposed American personnel to heightened risk, but one the president’s advisers saw as necessary to turn the tide against the Islamic State.
“I do think we’ve refined this strategy to a point where it’s become effective militarily,” said Faysal Itani, a senior fellow at the Atlantic Council, a Washington think tank. There are now about 300 Special Operations troops in Syria, providing support to allied forces.
But Itani cautioned that the outcome in Manbij would not necessarily translate easily to areas such as Raqqa, a larger and more strategically important city for the Islamic State.
He said the United States would increasingly be forced to contend with the fact that its military objectives may differ from those of the Syrian Kurdish forces it has leaned on to fight the Islamic State. Kurdish forces appear to be focused on their own territorial gains over the U.S. goal of capturing Raqqa.
“The main difference is that the [Kurdish force] is highly enthusiastic about moving west through Aleppo province toward Afrin canton,” Itani said. “I expect they’ll come under U.S. pressure to feel otherwise and head to Raqqa. At best, you’ll have a less motivated Kurdish component.”
While U.S. officials declined to say what the next military target would be, SDF forces already have hailed the creation of a new military council in al-Bab, to the southwest of Manbij, suggesting they will head there next instead of east toward Raqqa.
That would be a step toward connecting Afrin, which is one of three cantons that Syrian Kurds have self-designated for autonomous rule, to other Kurdishcontrolled areas. Any moves to expand territory under Kurdish control are certain to be met with opposition from Turkey, a U.S. ally with whom the United States is already scrambling to patch up ties in the wake of the failed coup attempt that took place there in July.
“It’s always a dynamic conversation in terms of prioritization,” the defense official said, referring to the next military objective. In Iraq, for example, the United States had pressed Iraqi officials to tackle the northern city of Mosul before militant-held objectives in the western province of Anbar; the Iraqis decided otherwise.
The Pentagon is now working to build up the Arab component of the SDF in preparation for a push toward Raqqa, but officials also acknowledge they will need help from the Kurdish forces.
U.S. officials saw Manbij as a potential model in mitigating the ethnic dimensions of the allied forces. While Kurds make up the largest share of the SDF, officials say the force that took Manbij was made up primarily of Arab fighters.
Col. Christopher Garver, a spokesman for U.S. military operations in Iraq and Syria, said that SDF forces, predominantly Arab fighters, are now working to ensure that no Islamic State fighters remain in Manbij, clearing the way for residents to return.
Speaking to reporters at the Pentagon, Garver noted that the clearing operation continued but gave a cautious assessment of where Kurdish forces would head once that concluded.
“It remains to be seen as to when it ends specifically and then what the follow-on response is to that,” he said.
The military advances by U.S.-backed forces also do not address the larger conflict that has been consuming Syria since 2011. Conditions have worsened in the nearby city of Aleppo, Syria’s largest, as rebels and Russian-backed government forces trade attacks.
Zakaria Zakaria contributed to this report from Istanbul.