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Turkish tanks near the Syrian border.

PolicyWatch 3121

If Syria Safe-Zone Talks Fail: How the SDF Might Respond to Turkish Intervention

John Holland-McCowan

Also available in العربية

May 17, 2019

The Kurdish-led force cannot hold the northeast on its own, and withdrawing coalition support would bolster Assad and Moscow’s interests.

As the United States, Turkey, and the Syrian Democratic Forces accelerated their discussions over a potential safe zone in northeast Syria in recent weeks, a surprise letter on May 6 added a new dimension to the talks. Following his first meeting with lawyers in eight years, Kurdistan Workers Party (PKK) leader Abdullah Ocalan issued a memo calling for “democratic negotiations” between the Kurdish-led SDF and Ankara in order to foster a “constitutionally enshrined local democracy within the framework of a united Syria.”

Sources close to the situation believe the timing of his letter was intended to facilitate a deal over the northeast Syria border zone, where the SDF—led by the U.S.-backed PKK offshoot the People’s Defense Units (YPG)—are in control. For months, Turkey and Washington have been negotiating a plan to jointly patrol a safe zone that would extend approximately twenty miles into Syria, with the SDF withdrawing from all buffer areas (the zone’s potential length and endpoints are still unclear). SDF representatives report that U.S. officials have been pressuring them to allow a limited number of Turkish forces in this proposed zone; Ocalan’s statement may encourage the group to be more flexible on these matters.

Yet while U.S. policymakers express confidence that such a deal can be reached and implemented, recent history should give optimists pause. If the talks fail, Turkish forces may decide to move into northeast Syria on their own accord. How might the SDF respond to unilateral establishment of a buffer zone?


SDF officials have long described the prospect of a Turkish military deployment in their northeastern stronghold as a nonstarter. They recognize that Ankara regards the YPG as a direct outgrowth of the PKK, which has waged an insurgency in Turkey since 1984 and been designated a terrorist group by Turkish, U.S., and EU authorities. Accordingly, the YPG and its political wing worry that any Turkish inroads in the northeast would existentially threaten the entire movement.

Recent precedent does not bode well for the viability of Turkish involvement either. After long negotiations, Washington and Ankara agreed on a roadmap last June to clear the SDF from Manbij, which lies just west of the Euphrates River section where the YPG’s core territory begins. The deal has yet to be fully realized, however. The joint U.S.-Turkish patrols called for in the agreement took months to be initiated, SDF fighters remain in the city, and sporadic clashes between Turkish-backed militias and SDF units still occur. The situation illustrates that even if a deal over the northeast is reached on paper, implementation could pose significant challenges.

In a March 31 speech, Turkish president Recep Tayyip Erdogan declared that “our target is now eliminating the terror structures in Manbij and east of the Euphrates.” He has repeatedly warned that he will establish a unilateral buffer zone in those areas if U.S. talks fail. His words should not be taken lightly given that Turkey has intervened in north Syria twice in the past three years: Operation Euphrates Shield in August 2016 and Operation Olive Branch in January 2018. Although Erdogan claimed that the goal of those operations was to counter the Islamic State, the former campaign focused on the SDF as much as IS, while the latter was entirely geared toward fighting the YPG and SDF.


Without the aid of the U.S.-led coalition, the SDF cannot be expected to successfully defend their territory against Turkey. Given the remarkable success that the YPG and, later, the SDF experienced in pushing back IS, outside observers may overestimate how self-reliant they can be against a conventional military foe.

For example, absent coalition airpower, they would not have been able to defend Kobane or seize Raqqa, Manbij, and much of Deir al-Zour governorate. It was their partnership with Western special forces, intelligence assets, and close air support that made their ground forces so potent. Without such backing, they most likely could not withstand an offensive by proxy forces with Turkish support, let alone the Turkish army itself. This is especially true on the unfavorably flat terrain of northeast Syria. Even when the YPG attempted to defend their mountainous western enclave in Afrin—terrain far more suitable to irregular warfare—Turkish-backed forces were able to capture it within a matter of months.

In light of these military realities, the SDF have no incentive to give Turkey extra pretext for further interventions, or to give Washington cause for withdrawing support. Thus, any notion that the PKK might reinvigorate its armed campaign in Turkey to deter aggression against its Syrian offshoot was likely off the mark even before Ocalan’s recent letter. From the beginning of the Syria war, the YPG and SDF have made it a priority to distinguish their campaign from the PKK’s fight in Turkey, and Kurdish officials are well aware that another outburst of PKK violence could spark Turkish action on both sides of the border.

If coalition support does in fact weaken, the SDF will most likely try to forge a deal with Bashar al-Assad and Russia in order to guard the northeast. Ever since they cemented their hold over the region, the YPG/SDF have generally cooperated with the Assad regime. For instance, the regime has maintained pockets of control in YPG-held Qamishli and Hasaka since 2011 with little friction besides occasional skirmishes.

Yet the SDF know all too well what fickle allies Damascus and Moscow can be, as illustrated during the Turkish seizure of Afrin. It was Russia’s withdrawal of troops from that pocket and the regime’s ceding of airspace to Turkey that paved the way for that offensive. A month after the operation began, the YPG desperately called on Assad to help them, but not even the limited presence of regime-affiliated militias could halt Turkish-backed forces.

In truth, Damascus has no desire to strengthen the Kurds despite coming to their aid on occasion. A now-emboldened Assad wants to bring more of Syria to heel, and the YPG’s proclaimed aspirations for a pluralistic, semiautonomous entity in the northeast are simply out of tune with the regime’s mentality.

Perhaps the gravest threat the SDF would face if Turkey unilaterally intervenes is maintaining internal cohesion. Survey data suggests that the group’s Arab components would defect if given the opportunity, whether the opposing forces in question are Erdogan’s or Assad’s. Despite the SDF’s ethnically mixed nature, most Sunni Arabs in northeast Syria have acquiesced to the Kurdish-dominated local administration primarily because it has secured American support and a monopoly of force. If Turkish-backed forces challenge this monopoly amid wavering coalition support, wide-scale Arab defections could render the SDF a primarily Kurdish outfit.

In that scenario, the overwhelmingly Kurdish remnants of the SDF would likely be forced to withdraw from mixed Arab-Kurdish or predominantly Arab areas such as Manbij, Tal Abyad, Raqqa, and Deir al-Zour, retreating to their isolated Kurdish enclaves in order to preserve what limited autonomy and power they have left. In doing so, they would simultaneously forfeit their best bargaining chips with the Assad regime while severely curtailing their utility to the United States and other coalition allies, who want to maintain a partner force in predominantly Arab areas that seem most vulnerable to an IS resurgence.

In short, a Turkish incursion could unravel the SDF at the seams. If current negotiations fail, U.S. policymakers must recognize that allowing Ankara to unilaterally establish a buffer zone may essentially eliminate the coalition’s best ally in Syria. To secure their protection, the SDF would be forced to seek a deal with the Assad regime and Russia, critically weakening U.S. influence in the region.

John Holland-McCowan is a research fellow at the International Centre for the Study of Radicalisation, a doctoral candidate at King’s College London, and an incoming postdoctoral fellow at Harvard’s Belfer Center for Science and International Affairs.