Since they were established eight years ago, the Syrian Democratic Forces (SDF) have maintained an often tense and delicate balancing act to maintain unity across what has always been a diverse coalition of localized actors. Nowhere has that SDF unity been more consistently tested than in Syria’s eastern governorate of Deir ez-Zor, where an array of Sunni Arab tribal factions exert control on the ground on behalf of an SDF leadership that they have more often criticized than praised. Much of the antagonism that has defined the SDF’s presence in Deir ez-Zor has been rooted in widespread local perceptions that the SDF’s leadership is dominated by Kurds, predisposed not to invest in Arab regions, and has favored corrupt and often brutal Arab figures to be its representatives there.

Throughout its five-year military campaign against ISIS and in the four years since ISIS’s territorial defeat, the SDF has managed to contain these persistent frictions, but that may now be coming to an end. In the past three days, at least 50 people have been killed in fighting between Arab tribal fighters and the SDF in the region where Syria’s Khabur and Euphrates rivers meet. The catalyst for this fighting occurred late on Aug. 27, when Ahmed al-Khubayl (“Abu Khawla”), the leader of the SDF’s Deir ez-Zor Military Council (DZMC), was lured north to Hasakah for a purported meeting, only to be arrested alongside his brother and four other DZMC commanders.

That arrest came in the wake of weeks of tensions between the SDF and Abu Khawla — someone with a notorious public profile. Prior to Syria’s uprising in 2011, he allegedly ran a gang involved in stealing motorbikes and abandoned properties. Though he went on to join the opposition cause, he was accused of assisting the regime in 2013 and briefly joining ISIS in 2014-15, before fleeing to Turkey. In late 2016, the U.S. military co-opted Abu Khawla and secured him a position as one of the SDF’s lead Arab military commanders. He led units against ISIS in Raqqa in 2017, before moving south into Deir ez-Zor. In late 2018, the SDF attempted to expel Abu Khawla from his role as chief of the DZMC, only to be blocked by the U.S. military, perhaps due to his deep ties within the al-Bakir tribe, from which ISIS had recruited a great many fighters.

In July, possible SDF plans to arrest Abu Khawla led to a lengthy standoff and an eventual SDF stand-down, but not this time. Since Aug. 28, the fighting triggered by Abu Khawla’s arrest has escalated exponentially. The SDF has lost at least 31 fighters so far, with dozens more assumed dead or captured. At least 19 localities have taken up arms against SDF rule and the SDF has been forced to deploy reinforcements from Raqqa and Tabqa, only for them to be ambushed multiple times with rocket-propelled grenades (RPGs) and improvised explosive devices (IEDs). Abu Khawla’s brother, Adham, has since escaped SDF custody and returned to Deir ez-Zor to lead what appears to be a fledgling anti-SDF insurgency. Some large tribes, such as the Baggara and most of the Shaytat, have so far stood by the SDF, but other tribes and clans, including Abu Khawla’s al-Bakir, as well as the al-Shuhayl, al-Dulaym, and Albu Khabur have taken up arms. Rising civilian deaths — including at least four young children — amid alleged SDF shelling of civilian areas risk irreversibly enflaming tensions.

The stakes here cannot be overstated. Since 2015, the U.S. has invested heavily in broadening the representation of the SDF. Within that effort, the DZMC was a crucial component, but never one whose complexity and socio-political nuances received sufficient attention and action. Should the SDF lose control of this strategically vital region, the U.S. military mission in northeastern Syria will be squeezed into an unsustainably tight corner. Two of the U.S. military’s most important facilities in all of Syria — the bases at Conoco and Omar oil fields — are literally in the heart of the ongoing fighting. The town of Dhiban, adjacent to the Omar base and routinely used by U.S. troops for patrols and transit, is now fully under the control of anti-SDF forces. Tribal fighters are presently setting up roadblocks and checkpoints on key roadways throughout the Euphrates-Khabur artery, on which U.S. troops rely.

For now, this spiraling fighting should not be described as an Arab-Kurdish conflict, but if it is allowed to continue much longer, it is headed in that direction. At its core, it is illustrative of a long suppressed but very real divergence at the heart of the SDF coalition, in which a sizeable proportion of Sunni Arab actors in eastern Syria have distrusted and critiqued SDF policies, but until now at least, had chosen to stick with the SDF over alternatives. Many of those now fighting the SDF represent what remains of eastern Syria’s armed opposition, whose determination to sustain a front against the regime has long been a thorn in the SDF’s side as it attempts to retain neutrality vis-à-vis Damascus. It is perhaps no coincidence that in recent months, Abu Khawla had allegedly resumed communication with the opposition in northern Syria and with authorities in Turkey.

Only a major and concerted U.S. effort will stop the current fighting and prevent it from spiraling out of control. U.S. troops in the Conoco and Omar bases have sought to engage tribal leaderships, but that may not be enough. Meanwhile, as the situation continues to escalate, only one actor stands well-positioned to benefit: ISIS.


Charles Lister is a senior fellow and the director of the Syria and Countering Terrorism & Extremism programs at the Middle East Institute.

Photo by Rami Alsayed/NurPhoto via Getty Images

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