Although the U.S.-allied forces and the Iranian-aided militias are both fighting the Islamic State, they also are in competition for sway over parts of Syria if the Islamic State loses more ground. Most important of all is Deir al-Zour, the largest swath of Syria to remain under the extremist group’s control.
The closure also could put more territory under control of Iranian-sponsored Shiite militias that have pushed through the province in recent months. The pro-Syrian government forces, equipped with armored vehicles and pickup trucks, came dangerously close to U.S.-backed Syrian fighters over the summer. Their proximity sparked multiple incidents that included strafing runs on the militias by American aircraft and the shooting down of two Iranian-built drones, one of which occurred near the base at Zakaf.
Col. Ryan Dillon, a spokesman for the U.S.-led coalition in the region, said over email that the “decision to establish and close temporary bases is determined by operational requirements and the progress of the campaign.”
“Throughout Syria and Iraq, the Coalition has established and closed numerous bases, as warranted by the operational situation, in order to ensure we provide effective support to our partner forces,” he wrote.
A local resident, Mahmoud Abu Salah, confirmed that the outpost had been evacuated in recent days.
Dillon added that coalition troops and their Syrian partner forces — known as the Maghawir al-
The group’s fortunes, like those of most other Washington-backed rebels, have waned following defections and the ebbing of international support.
Recent advances by forces loyal to Syrian President Bashar al-Assad have effectively ended hopes of any meaningful anti-Islamic State offensive out of Tanf. But the withdrawal of coalition forces could now have unintended consequences elsewhere in the desert province, including the removal of the protection it offered tens of thousands of civilians through proximity to their nearby displacement camp.
It is unclear if the closure of the Zakaf outpost is the result of a cease-fire deal for parts of Syria reached in July by Jordan, Russia and the United States or from further unreported discussions between the countries.
Zakaf was constructed this summer and the Maghawir al-Thawra posted multiple pictures of the outpost to its media arm showing U.S.-led coalition forces mingling among their fighters, and boasted to news outlets about its key location. The small fortification appeared to be an effort by the U.S.-led coalition and the Maghawir al-
The offensive stalled and ultimately failed, forcing the Syrian fighters to retreat across the desert to Tanf. Since their defeat, the New Syrian Army changed its name, was re-equipped and retrained by British and U.S. Special Operations Forces and quietly began pushing back toward Bukamal.
Over the summer, however, the Syrian Army and its Iranian-backed proxies effectively cut off the U.S.-backed forces from any overland approach to Bukamal, bypassing the coalition’s outposts at Tanf and Zakaf and linking up with their Iraqi counterparts at the Iraqi border. Since then, U.S. officials have said that the Maghawir al-
The shuttering of Zakaf comes as another U.S. proxy group, known as the Syrian Democratic Forces, or SDF, continues to make gains in the northern Euphrates River Valley and in the Islamic State’s de facto capital of Raqqa. Roughly 70 percent of the city has been retaken from the militant group as the urban battle stretches into its third month. The SDF has also recently pushed south of Raqqa toward the Islamic State-held city of Deir al-Zour. With Maghawir al-Thawra sidelined, Dillon said that the SDF will effectively take the lead to seize Bukamal, approaching the town from the north instead of the west.
“With the SDF, we are talking about supporting them all the way down in what remains of ISIS territory in Syria to defeat ISIS, and that includes Bukamal,” Dillon said.
Last week, the Pentagon accused Russia of bombing the SDF. While Russia did not take responsibility for the attack, Chairman of the Joint Chiefs Gen. Joseph F. Dunford Jr. spoke with his Russian counterpart on Saturday and agreed to closer military discussions to ensure U.S.-backed fighters and Syrian and Russian forces avoid each other in the increasingly congested area.
Louisa Loveluck and Liz Sly in Beirut and Zakaria Zakaria in Istanbul contributed to this report.