U.S. Marine Corps firing a howitzer in Syria, June 2017. Photo Credit: Sgt. Matthew Callahan, U.S. Marine Corps


On January 11, the spokesman for the U.S.-led coalition against the so-called Islamic State (otherwise known as ISIS) announced the beginning of the withdrawal of the approximately 2,000 U.S. troops stationed in Syria. Yet since President Trump’s sudden announcement of his plan to pull U.S. forces from the country on December 19th, 2018, details on how and when Washington will disengage from Syria have been few and far between.

One of the many questions this development poses is which force will ensure ISIS’s defeat in Syria once the U.S. withdraws? While certainly on the back foot, ISIS remains a potent insurgency and a grave threat to regional stability. The movement has demonstrated a remarkable ability to perpetuate terrorist and hit and run attacks in territory they have supposedly lost in both Iraq and Syria. This short piece will sketch out the prospects of regional powers such as Turkey, the Syrian government, and the Kurdish-led Syrian Democratic Forces (SDF) leading the fight.

On January 7th, Turkish President Recep Tayyip Erdogan published an op-ed piece in The Washington Post titled “Erdogan: Trump is Right on Syria. Turkey Can Get the Job Done.” He writes that in “2016 Turkey became the first country to deploy ground troops to fight the so-called Islamic State in Syria.” He claimed that it had “severed the group’s access to NATO’s borders and impeded their ability to carry out terror attacks in Turkey and Europe.”

In reality, the timing of the Turkish operation in August 2016 coincided much more closely with recent advances of the US-led coalition’s SDF allies west of the Euphrates River than with ISIS’s multiyear presence along the Turkish border. The Turkish-backed offensive was triggered by Ankara’s efforts to bar the People’s Protection Units (YPG) from territorially linking up with their counterparts throughout northern Syria. Turkey considers both the SDF and YPG as largely synonymous with the Kurdistan Worker’s Party (PKK), a group the EU, U.S., and Turkey label a terrorist group.

Ankara’s top priority in the Syrian conflict remains to prevent a semi-autonomous region developing under the SDF’s control in northern Syria. Despite Erdogan’s rhetoric, Turkey has not shown its commitment to comprehensively defeat the so-called Islamic State in Syria. It is notable that neither the Turkish-backed Operation Euphrates Shield in August 2016 nor Operation Olive Branch in January 2018 were aided and abetted by their NATO allies. Rather than Turkish force of arms, it was the YPG and SDF that served as the tip of the spear of the anti-ISIS coalition in Syria.

The Trump administration’s requests for Turkey to provide guarantees that they will not attack the YPG and SDF in the wake of a U.S. withdrawal have been flatly rebuked. Ankara’s escalating saber-rattling, arguing that their upcoming Syrian offensives will not be dependent on a U.S. pull out, is notable. Turkish aggression against the principal allies of the U.S.-led coalition in Syria, forces that have proven fundamental in driving the ‘Caliphate’ into the desserts of eastern Syria, will further neither U.S. national security interests nor regional stability.

The Assad Regime?
Like Ankara, Damascus has shown scant enthusiasm for recapturing ISIS territory unless particularly valuable land risked being recaptured by geopolitical rivals. Such was the case when the U.S.-backed SDF threatened to capture much of the Deir ez-Zor governorate of eastern Syria. In fact, despite Bashar Assad’s claims to be a secular bulwark against extremism, he has demonstrated a propensity for fostering or neglecting the jihadist threat in his own country while crushing more moderate and palpable opposition groups throughout the Syrian Civil War.

Furthermore, ISIS’s hit and run operations continue in territory the regime reportedly recaptured. Widespread resentment in eastern Syria towards Damascus could exacerbate the problem, driving more locals into the extremists’ ranks if the regime attempts to strengthen its grip.

With Assad’s stated objective to recapture every inch of Syria, ISIS’s remnants in eastern Syria pale in comparison to his desire to bring rebel-held Idlib back into the fold. Recent efforts by the Syrian Kurds to enter negotiations with the central government over the status of northern Syria have borne little fruit. Bashar Assad’s recent authorization for Iraqi forces to attack the Islamic State in Syria indicates a willingness to increase security cooperation with its eastern neighbor, although the extent and impact of this cooperation remains to be seen. The longer ISIS and its extremist ilk remain in Syria, the longer the regime can justify its actions against other opposition groups it indiscriminately calls “terrorists.”

The SDF?
Are the Syrian Kurds and their allies strong enough to defeat ISIS on their own, while simultaneously deterring their regional adversaries in Damascus and Ankara? Indeed, the YPG did a respectable job fighting ISIS and other rebel groups on its own up until mid-2014 when the U.S. came to their aid during the pivotal siege of Kobane. Over the coming years, they proved their fighting metal with their ability to function alongside the U.S.-led coalition forces and became one of the strongest political and military forces in Syria.

Nevertheless, the SDF is critically vulnerable without the accompanying U.S. presence. This was most recently illustrated with the YPG’s reversals in the face of the Turkish-backed offensive in Afrin starting in January 2018. The possibility of losing some if not all of the training, equipment, and air support they have previously received will substantially reduce their combat effectiveness, hazarding all the gains they have made.

Turkish operations against them are their greatest fear. The SDF’s operations against ISIS positions in Deir ez-Zor were temporally suspended whether it was in response to Operation Olive Branch or Turkish shelling of Kurdish positions in northeastern Syria. Anticipating a Turkish offensive against the SDF-controlled city of Manbij, potentially absent U.S. protection, the Kurds have asked Damascus to send troops to protect the city. In short, the Syrian Kurds should not be expected to defeat ISIS while fending off NATO’s second largest army in Turkey on their own.

Mission Not Accomplished
The ‘Caliphate’ is far from beaten. As the battle for eastern Syria continues, thousands of ISIS fighters reportedly remain at large. Hit and run and terrorist attacks continue across the country, most recently with a suicide bomber that killed 14 people, including 4 Americans, in the northern city of Manbij. Notwithstanding, as the U.S. pullout has been initiated, there are no clear candidates who will lead the fight in their stead.

There may be a couple of alternatives however. Could other partners in the 68-member U.S.-led coalition carry the torch? In particular, absent U.S. troops, could France and the UK fill some of the void with their own soldiers? A more robust French and British presence in northern Syria could continue to train, equip, and cooperate with the SDF in the fight against ISIS while simultaneously acting as a strong deterrent against Turkish-backed forces. Turkey will not want to endanger the lives of Western special forces, whether they are French, British, or American, who are embedded within SDF positions.

In conclusion, policy makers should recognize that regional players such as Ankara, Damascus, and the Syrian Kurds have yet to prove their willingness or capacity to comprehensively defeat the so-called Islamic State. The ongoing U.S. withdrawal from Syria is a decision well worth revisiting.