BEIRUT — The call came around noon, about four hours after U.S.-backed Syrian fighters announced they had taken over an air base outside a town held by the Islamic State group near the Iraqi border. “We are trapped. Pray for us,” a commander called into the operation room.
Then communication was cut. Six hours later, the exhausted fighters from the group, known as the New Syrian Army, returned to their base in Tanf, nearly 150 miles across the desert to the west, having lost four fighters, four vehicles and ammunition.
The swift, humiliating defeat last Wednesday marked the end of a widely advertised offensive launched less than 24 hours earlier with intense U.S.-led air cover. The fighters had hoped to capture Boukamal, a prize possession of IS and the extremist group’s last border crossing between Iraq and Syria.
The Boukamal offensive was the first serious attempt to take on IS in the northeastern province of Deir el-Zour, and the first major test for the nascent force of some 1,000 fighters, formed in November from a coalition of Syrian army defectors, local militias and Islamist fighting groups, many of them from the area.
The quick collapse of the offensive reflects the difficulties the U.S. faces in creating an effective Syrian force against IS, given the complex terrain, competing personal and tribal loyalties — and the extremists’ continued ability to fight on multiple fronts.
The U.S. has struggled to find local partners in Syria. The exception has been the Kurds, who heavily dominate the U.S.-backed Syrian Democratic Forces, which have had success wresting territory from IS in the north.
All other known attempts to train rebel groups have largely failed, in part because of Washington’s focus on the fight against IS rather than toppling the Syrian government, and its failure to protect its partners from better-equipped rivals.
The offensive on Boukamal, a city of nearly 160,000 people along the Euphrates River — mostly Sunni Arab tribes that move freely between Iraq and Syria — aimed to take advantage of IS’ focus on defending its northern stronghold of Manbij, which is under attack by the SDF.
Some 200 New Syrian Army fighters took part in the Boukamal operation, according to activists and media reports. They had extensive air support from the U.S.-led coalition, a vote of confidence in the new force, said Jennifer Cafarella, of the Institute for the Study of War. But the group “is definitely not off to a good start,” she told The Associated Press.
Commanders of the U.S.-backed militia say they have received extensive training since June last year by U.S. and British special forces, with the Jordanian military playing an advisory role. Activists and observers say the group appears to have equipment and weapons not often seen with other rebels, such as special vehicles for difficult terrain and exclusively U.S.-made small arms.
U.S. officials have not specified the extent of their support for the group, which has been channeled through the Pentagon. The U.S. military refers to the New Syrian Army as a “partner.”
The group’s first major operation — though much smaller than the Boukamal push — was in March, when it took over Tanf, a smaller IS-held crossing on the border with Jordan.
Ahead of the Boukamal offensive, the American-backed fighters posted a number of messages online indicating that an attack was imminent and taunting IS as “rats.” Days before the New Syrian Army offensive, IS announced it had killed five Boukamal residents, describing them as spies.
The fighters made gains early on, taking the small Hamdan air base — but then the offensive quickly unraveled.
A member of the New Syrian Army debriefed on the battle said the American-backed force closed two or three routes to the base but left another one unguarded. IS then used that approach to attack and surround the facility. The member of the force spoke on condition of anonymity because he was not authorized to speak to reporters.