As the Syrian Democratic Forces (SDF) approach the northern suburbs of Raqqa, the long-running policy debate over the advisability of using as a primary U.S. partner a militia that is dominated by the People’s Protection Units (YPG), has reached fever pitch. Dire warnings have been made of the risks to eastern Syria’s future stability that may result from a reliance on a Kurdish-led force with links to the Kurdistan Workers’ Party (PKK, Partiya Karkerên Kurdistanê), to storm the city and possibly even govern it once it has been captured.

The increasingly bitter tone of the debate is only partly a reflection of the complex social and cultural dynamics of the diverse population of northern and eastern Syria. Instead, it is primarily a result of the intractable conflict north of Syria’s border, in Turkey’s restive and overwhelmingly Kurdish south-eastern provinces. Turkey’s failure to field a viable rebel force for the Raqqa operation has led to a deepened U.S. engagement with the YPG, sharpening Turkish fears that northern Syria will become a PKK training and logistics hub (al-Monitor, March 27).

In its search for a local solution to the problem of northeast Syria, the United States has found itself increasingly held hostage to dynamics outside its own control, with the growing risk that American troops will be drawn into a conflict they cannot adequately manage. In seeking to defeat Islamic State (IS) and establish stable governance in what is fast becoming an unofficial mandate territory, the United States will have to manage the expectations of both its Kurdish and Turkish allies, as well as their respective Arab proxy forces.

Expanding the Arab-Kurd Binary

For primarily political reasons — both local, in ensuring the compliance of Arab populations, and regional, in assuaging Turkey’s concerns of Kurdish dominance — the SDF has placed great emphasis in putting an Arab face on the Raqqa operation, recruiting Arab fighters in ever-growing numbers (Rudaw, March 28).

Some Arabs have joined purely Arab militias, such as the Manbij Military Council or the Shammar tribal outfit Jaish al-Sanaddid (ANHA, April 18; ANHA, July 15, 2015). Increasingly others, however, have joined the ranks of the predominantly Kurdish YPG and Asayis gendarmerie forces (ANHA, February 27). Yet the precise ethnic balance between Kurds and Arabs within the SDF, despite its political and tactical importance, remains unknown to outside observers, with differing estimates given even by the coalition.

It has become axiomatic among advocates for the Syrian rebels that only predominantly Arab forces can hope to take or hold Raqqa. There is little evidence for this position. Identical claims were made about the YPG’s ability to capture or hold the predominantly Arab cities of Tal Abyad and Manbij. However, in the years and months since their capture from IS, no military or political resistance to Democratic Union Party (PYD, Partiya Yekîtiya Demokrat‎) rule has taken hold.

Instead, the PYD has devolved government to local Arab-led civilian councils, and recruitment to predominantly Arab SDF militias has proceeded at a steady rate (ARANews, August 10, 2016). It is reasonable to consider that an excessive focus on ethnic conflict between Kurds and Arabs in northeast Syria, fueled by often simplistic coverage that reduces the region’s complexities to binary Kurd-Arab hostility, is as much a spoiling effort to prevent PYD expansion as it is based upon genuine concern for local stability, or indeed on any appreciation of local realities.

Yet as the SDF move south into the tribal Arab heartlands of Raqqa and Deir Ezzor, the U.S. troops accompanying and supporting them are moving into unknown territory, tasked with ensuring the pacification and compliance of tribal Arab populations whose loyalties and political aspirations are almost wholly unknown. In the ensuing policy debate, the Arab tribes of northern and eastern Syria have been treated like blank sheets upon which the political desires of local and regional actors have been projected. What they themselves want remains largely unknown.

Regime Loyalties

The tribes of northern and eastern Syria were little studied before the war, and inaccessible to impartial researchers after (Syria Deeply, December 11, 2015). Where they have come to the world’s attention, it is only as instruments of propaganda, swearing fealty to the Syrian regime, IS or PYD, as determined by the ebb and flow of the front lines. It is unclear to what extent the war’s hardships have revitalized the bonds of mutual defense among tribesmen that segmentary theory would suggest; or whether the ever-growing array of external sponsors has encouraged greater division within tribal units, as rival chiefs battle for supremacy, or youths discard the age-old tribal loyalties for the new bonds of duty and affection offered by armed groups with more ambitious goals.

In rural Deir Ezzor, the case of the Shaitat tribe affords a vivid example of the choices tribal units make under the pressures of war. One of eastern Syria’s most powerful tribes, with around 90,000 members, the Shaitat joined the rebellion at the outset and took control of many of the region’s lucrative oil wells.

As IS conquered almost all of eastern Syria in 2014, the Shaitat bore the brunt of some of the bitterest intra-jihadist fighting of the war in a bloody summer campaign along the lower Euphrates Valley (al-Monitor, June 25, 2014; Syria Deeply, August 1, 2014). At least 800 Shaitat tribal fighters were massacred by IS forces (al-Monitor July 2015). Many survivors fled to regime territory, and they have since reconstituted themselves as a warlike and highly-motivated loyalist militia defending the beleaguered Deir Ezzor SAA garrison from frequent IS assaults (The National, November 11, 2014; Youtube, September 25, 2015).

In Hasakah, meanwhile, the PYD has struggled to win the loyalties of tribes long affiliated with the regime through decades of patronage and clientelist politics (Zaman al-Wasl, March 29, 2016). Despite an ongoing Arab tribal outreach effort on the PYD’s part, the Tayy tribe has remained loyal to Damascus, providing the bedrock, along with a section of the region’s divided Christian population, of the local loyalist National Defense Force (NDF) militia (see Terrorism Monitor, March 24).

Dangers of ‘Weaponizing’ Tribal Structures

Rumours of the existence of loyalist underground militias years after the city’s fall to the rebels and some months into IS rule suggest that once in Raqqa the PYD will, after the city’s liberation from IS, find itself competing with the Syrian regime for the loyalty of its inhabitants (Aymenn Jawad, July 29, 2014). Furthermore, local tribes may use the comparative strength and reach of the regime and the PYD’s competing external sponsors of Russia, Iran and the United States as bargaining chips as they weigh up the costs and benefits of loyalty to one faction or another, or indeed of inter-tribal competition.

Even within the Arab tribe most committed to the PYD project, the Shammar confederation, it is apparent that the SDF umbrella contains two politically distinct militias with perhaps widely differing political desires.

On the one hand, the SDF’s long-time allies, the Jaish al-Sanaddid, led by Sheikh Humaydi Daham al-Hadi, are utilized primarily as a mobile gendarmerie to provide security over thinly populated desert areas, appearing to view this as an opportunity to re-establish their long-lost historical suzerainty over the eastern Syrian desert. On the other, the Syrian Elite Forces, composed of Shammar and Shaitat tribesmen and led by former Syrian National Council head and Shammar aristocrat Ahmad Jarba, seem keen to establish a notional rebel-branded autonomy within the framework of SDF rule (NOW Lebanon , May 26, 2016). This militia has perhaps set its sights on a governance role in either Raqqa or Deir Ezzor.

In seeking to weaponize Syrian tribal structures against IS, the United States will have to approach tribal politics with a keen anthropological eye, taking care to ensure it is not laying the foundation for future clashes between tribe and clan factions in the aftermath of the current conflict. Managing the divergent political aspirations of disparate factions within a broad multi-ethnic coalition is a complex task, and the United States should analyze local political divisions carefully before disbursing weapons and ammunition in significant quantities.

The ability of the United States and its SDF allies to win over tribes like the Tayy or Shaitat, or at least avoid the need to confront them, will depend greatly on what concrete advantages in wealth or influence cooperation with the new governing power will grant them, as well as upon the hope that Russia, Iran or Damascus — or even some new form of jihadist insurgency — will not seek to wreak havoc in the Euphrates Valley for its own ends.

Cautious Disengagement

As the SDF sweeps into Raqqa city, and perhaps rural Deir Ezzor, the U.S. troops supporting them will find themselves providing military and logistic support to a Kurdish-led indirect-rule project of uncertain duration over local Arab tribes. The political desires of those tribes are largely unknown, and the tribes themselves may well be deeply divided.

Given that the Syrian regime, various rebel factions and an al-Qaeda offshoot drawn from local tribes have each been unable to hold these regions, the ability of what will likely be seen as a doubly foreign occupying force to do so without being sucked into a grueling counterinsurgency campaign is an open question.

U.S. policymakers need to be clear on the U.S. exit strategy and what the desired end-state is for the Euphrates River Valley region, before being pulled into an open-ended occupation by the power vacuum the retreat of IS-established borders will create.

The longstanding, if fragile, coexistence between the PYD and the Syrian regime in the cities of Qamishli and Hasakah may present an opportunity for U.S. forces to disengage from the region in the near-to-medium future (al-Araby, August 26, 2016; Syria Direct, April 26).

While advocates for the Syrian rebels will likely see a U.S. presence in the region as an opportunity to establish some form of rebel rule under military protection, the advisability of enforcing failed rebel governance structures in this volatile border region by force of U.S. arms remains questionable at best.