What’s new? President Trump's surprise decision to withdraw U.S. troops from Syria followed previous warnings that he justified their presence only as part of the campaign to defeat the Islamic State (ISIS). Trump said the mission is accomplished, though ISIS remains active in both Syria and Iraq.

Why does it matter? The U.S. has not laid the political groundwork for withdrawal without precipitating new conflicts. Its Syrian partners fighting ISIS, led by Kurdish fighters, will be vulnerable to attack by either the Syrian regime or neighbouring Turkey. The ensuing conflict could have devastating humanitarian consequences and provide ISIS with the chance to regroup.

What should be done? The U.S. needs to press Turkey not to attack the Kurdish-led Syrian Democratic Forces (SDF). It should encourage the SDF to reach a stabilising deal with the Syrian regime, as, in parallel, Russia engages the SDF, the regime and Turkey. More space and time granted by Washington, even if limited, could allow for an orderly U.S. exit.

On 19 December, days after U.S. President Donald Trump spoke with his Turkish counterpart, Recep Tayyip Erdoğan, U.S. officials announced that the U.S. had begun to withdraw its military forces and civilian personnel from north-eastern Syria. Trump had told Erdoğan that such was his intent, but to most everyone else, the news came as a surprise and, to many, a perilous one: if made precipitously, the move risks leaving chaos in its wake. Washington’s Syrian partners in the fight against the Islamic State (ISIS), led by Kurdish fighters, will be vulnerable to attack by either the Syrian regime or neighbouring Turkey, which considers them terrorists. The ensuing conflict could also provide ISIS with the opening it needs to regroup.

It almost certainly was unwise to commit the U.S. to an open-ended military presence in Syria’s north east, as U.S. officials had previously done. But if the U.S. is to pull out its troops, it should ensure that its partners in the Syrian Democratic Forces (SDF) can survive without them. At this point, the U.S. has not yet laid the political groundwork that would allow it to withdraw responsibly.

As it reaches the final stages of its military campaign against ISIS, the U.S. needs to press Turkey not to attack the Kurdish forces and simultaneously to facilitate a stabilising deal between the Kurdish-led SDF and the Syrian regime. It will not be easy. Talks earlier this year between representatives of Syria’s north east and Damascus stalled after the regime refused to bend on demands for decentralisation and local autonomy. The regime’s negotiating position may become even more inflexible now that the U.S. has announced its departure and thus the guarantee of its military protection is set to expire.

Still, an imminent U.S. withdrawal should drive home the urgent need for a deal – one that restores Syrian state sovereignty to Syria’s north east; moves Syrian forces to the border with Turkey, with Russian backing, thus assuaging Turkish security concerns and forestalling an attack on the SDF; and allows for a degree of Kurdish self-rule. In recent months, the U.S. had not encouraged the SDF to seek such a deal; that posture must now change. The SDF needs the space and time to bargain seriously with Damascus. The alternative could be a military free-for-all resulting from a conflict among the SDF, Turkish and Syrian forces that could have devastating humanitarian consequences and regenerate ISIS.

Trump’s decision to pull military forces out of Syria is the latest wild swing in U.S. Syria policy during his presidency, as the U.S. national security staff has repeatedly battled the president’s own instinct to avoid open-ended engagements in the Middle East.^[fn]See Aron Lund, “The Making and Unmaking of Syria Strategy under Trump”, The Century Foundation, 29 November 2018.Hide Footnote Until Trump’s about-face, those officials tied the presence of U.S. troops to ISIS’s “enduring defeat”, which, per their expansive definition, required fundamental change to Syria’s political system and the exit of Iranian-commanded forces from Syria.^[fn]“Briefing on Syria Meeting and U.S. Strategy”, U.S. Department of State, 27 September 2018. Ambassador James Jeffrey, the U.S. special representative for Syria engagement, elaborated on the logic of “enduring defeat” in his 29 November testimony to a House of Representatives foreign affairs subcommittee: “First of all, you cannot ensure the enduring defeat of ISIS – that’s what we experienced, including me personally in Iraq in 2010 to 2012, of any terrorist organization –if you don’t deal with the root causes of it. Well, the root causes of ISIS, mainly in Syria but to some degree in Iraq, have been, first of all, the horrific behavior of the Assad regime against its own people, giving those people no other chance but to turn to whomever would take up arms against Assad, and that was, unfortunately, including terrorists. Secondly, it is the role of Iran, spreading its tentacles around the Arabic Sunni world. This is an outside force that creates malignant antibodies if we – that is, the international community – do not respond in a proper way. We did not respond in a proper way to Iran’s encroachment into these areas so the peoples of the area, in desperation, fell victim to the false claims, the false promises of ISIS and other terrorist organizations. So we do have to do all three. We cannot just rely on the military defeat of the Caliphate right now along the Mesopotamia, the Euphrates, along the Iraqi border. We have to go after the root causes, and our policy is aimed at that”. “U.S. Policy in Syria”, C-SPAN, 29 November 2018 (at minute 15:12).Hide Footnote Now Trump has reasserted himself. “We have defeated ISIS in Syria, my only reason for being there during the Trump Presidency”, he tweeted on the morning of the 19 December withdrawal announcement.^[fn]Tweet by Donald J. Trump, @realDonaldTrump, U.S. president, 7:29 am, 19 December 2018.Hide Footnote

President Trump first made the policy shift – unbeknownst to the State Department or the Pentagon – during a 15 December telephone call with Turkish President Erdoğan. Over the previous month, Turkey had stepped up its pressure on Washington over the U.S. presence in north-eastern Syria. It had become clear to Ankara that ISIS’s “enduring defeat” meant Washington’s continued sponsorship of the SDF and support of an SDF-controlled territorial entity. The SDF is led by the People’s Protection Units (YPG), the Syrian manifestation of the Kurdistan Workers’ Party (PKK), which has waged a decades-long insurgency in Turkey; Ankara accordingly considers it a terrorist organisation and any U.S. support for it intolerable. When the U.S. military established observation posts along the Syrian-Turkish border in late November – to protect Turkey from cross-border infiltration, U.S. officials claimed – Ankara only grew angrier, viewing the move as a hostile act designed to shield its mortal enemy, the PKK.^[fn]David Vergun, “U.S. Setting Up Observation Posts on Syria-Turkey Border”, U.S. Department of Defense, 21 November 2018.Hide Footnote

On 12 December, Erdoğan announced that Turkish forces would intervene in Syria “within days”. This declaration set off alarm bells in Washington.^[fn]“Turkey will launch new military operation in Syria within days: Erdoğan”, Hürriyet Daily News, 12 December 2018.Hide Footnote The Pentagon warned that an attack on Syria’s north east would be “unacceptable”.^[fn]Ryan Browne, “US warns Turkey not to attack Syria”, CNN, 12 December 2018.Hide Footnote When Trump spoke to Erdoğan on 15 December, U.S. officials expected him to forcefully reiterate that message. He did not. Instead, he shocked his own staff by telling the Turkish president that an attack by Turkey made no sense since the U.S. would be imminently withdrawing from Syria. Summarising the mood among some, a top official, referring to the chaotic U.S. withdrawal from Vietnam decades ago, reportedly commented, “I was not hired to preside over another Saigon”.^[fn]Crisis Group interview, senior U.S. official, December 2018.Hide Footnote

Stunning as it was, Trump’s decision should not have come as a real surprise. He has consistently emphasised that his interest in Syria is limited to defeating ISIS.^[fn]For example, see Monica Langley and Gerard Baker, “Donald Trump, in exclusive interview, tells WSJ he is willing to keep parts of Obama health law”, Wall Street Journal, 11 November 2016.Hide Footnote In March 2018, he undercut a previous open-ended commitment to remaining in Syria by declaring, unprompted, that the U.S. would withdraw its forces from Syria “very soon”.^[fn]Michael Crowley and Nahal Toosi, “Trump wants ‘out’ of Syria ‘very soon,’ contradicting top officials”, Politico, 29 March 2018. For the iteration of U.S. Syria strategy that President Trump upended with his March and April remarks, see “Remarks on the Way Forward for the United States Regarding Syria”, U.S. Department of State, 17 January 2018.Hide Footnote In subsequent internal deliberations, he opted to pull out of Syria even at the potential cost of leaving a vacuum that, his aides warned, could be filled by Russia and Iran.^[fn]Matthew Lee and Josh Lederman, “Trump wants out of Syria, but don’t say ‘timeline’”, Associated Press, 6 April 2018.Hide Footnote

In the ensuing months, Trump’s national security staff – with an assist from French President Emmanuel Macron^[fn]“Syria air strikes: Macron says he convinced Trump not to pull out troops”, BBC, 16 April 2018.Hide Footnote – convinced him to remain in Syria as part of a regionwide strategy of “maximum pressure” on Iran.^[fn]Karen DeYoung, “Trump agrees to an indefinite military effort and new diplomatic push in Syria, U.S. officials say”, Washington Post, 6 September 2018.Hide Footnote But that consideration could only override his hard-wired preferences for so long.

In truth, from the outset the Trump administration’s plan to use the U.S. presence in Syria’s north east to curtail Iranian influence in Syria was both unrealistic (a few thousand U.S. troops were never going to make a discernible difference to Iran’s influence) and impracticable. It also risked inviting a dangerous counter-escalation by the Syrian regime and its allies. The withdrawal announcement arguably solves those potential problems.

But if it might address some problems, it could create another: for all their talk of ISIS’s “enduring defeat”, U.S. officials may have given it a new lease on life. Indeed, if a rushed withdrawal prompts a military free-for-all involving the SDF, Syrian regime and Turkish forces, ISIS could exploit the ensuing chaos to stage a comeback. More broadly, and ironically, by stretching the concept of ISIS’s “enduring defeat” to include an assortment of dubiously related goals over an unlimited timeframe – rather than setting a discrete goal and planning for a managed exit – U.S. officials may have missed the opportunity to secure the counter-ISIS campaign’s gains after a U.S. withdrawal. Instead, they may have set up the U.S. for a sudden, wrenching exit that raises the risk that ISIS’s defeat could be at least partially undone.

Trump’s tweet notwithstanding, ISIS is not yet defeated. It retains a stubborn territorial foothold along the banks of the Euphrates near the border with Iraq, where its fighters have held off the SDF for more than a year.^[fn]Falih Hassan and Rod Nordland, “Battered ISIS keeps grip on last piece of territory for over a year”, The New York Times, 9 December 2018.Hide Footnote It has underground cells that continue to carry out bombings and assassinations beyond that river enclave in both Syria and Iraq. It also has an unknown number of sympathisers among local communities that the organisation ruled for three years.^[fn]See Liz Sly, “America’s hidden war in Syria”, Washington Post, 14 December 2018.Hide Footnote

Effectively defeating ISIS does not require a long-term U.S. military presence in north-eastern Syria. An ongoing U.S. military deployment could in fact stoke destabilising resentments over the medium term, as the Syrian regime and others encourage loyalists and disgruntled locals to engage in violence and sabotage.^[fn]Crisis Group interviews and communications, January-May 2018. See Crisis Group Middle East Report N°190, Prospects for a Deal to Stabilise Syria’s North East, 5 September 2018.Hide Footnote Eventually, U.S. forces were going to – indeed should – leave. But this ought to have been preceded by a minimum of preparation. Instead, promises of a sustained presence were followed by the announcement of a swift exit. An abrupt, uncoordinated U.S. withdrawal could expose the U.S.’s Kurdish allies to deadly attack by Syrian regime and Turkish forces, with the ensuing chaos allowing ISIS to make a resurgence.

The most immediate and troubling effect of the U.S.’s withdrawal announcement is to leave the north east’s residents and the U.S.’s main local ally in the counter-ISIS campaign, the Kurdish-led SDF, in the lurch.

In recent months, the SDF has engaged in talks on future administrative and political arrangements with the Syrian regime, albeit without success. Trump’s March 2018 remarks which suggested the U.S. was leaving had spurred the SDF to initiate talks with Damascus; in July and August, an SDF-linked civilian delegation met with government officials in the Syrian capital. Behind the scenes, Russia also was playing a brokering role. Negotiations quickly reached an impasse, however. Damascus suggested only minor adjustments to local civil administration within the regime’s current structure, while the SDF-linked representatives insisted on negotiations over Syria’s constitution and more substantive decentralisation.^[fn]Crisis Group interviews, YPG/PYD officials, north-eastern Syria, July-August 2018. See Crisis Group Report, Prospects for a Deal to Stabilise Syria’s North East, op. cit.Hide Footnote Meanwhile, once the Trump administration had (seemingly) decided to remain indefinitely, U.S. officials assured their SDF partners that the U.S. was staying, relieving any pressure to deal. U.S. officials shifted their tone on negotiations with the regime, discouraging the SDF from pursuing talks.^[fn]Crisis Group interviews, U.S. officials, December 2018.Hide Footnote

Now, the SDF will need to resume the talks in earnest, albeit from a far weaker bargaining position. Historical YPG/PKK ties with Damascus could help push them forward, but the impasse previously reached demonstrates the wide gap between what the SDF wants and what Damascus is willing to give. That gap must be closed if the two sides are to arrive at a deal that can plausibly forestall a Turkish attack on the SDF.

Both sides have reasons to deal. The SDF undoubtedly has the greater incentive; it is the party facing the prospect of Turkish invasion somewhere along Syria’s long northern frontier. Ankara is justifiably confident that it can crush an SDF deprived of U.S. military support after overwhelming the YPG earlier this year in Afrin, an enclave in Syria’s Aleppo province with more difficult hilly terrain. But Damascus also needs an agreement. Without a deal, the regime risks losing more Syrian territory to Turkey. Syria is still protesting Turkey’s “salkh” (skinning off) of coastal Iskanderun from Syria in 1938.^[fn]“On the anniversary of the crime of skinning off Liwa Iskanderun… A right does not die so long as demands are behind it”, SANA, 29 November 2018 (Arabic). Iskanderun – today, Turkey’s Hatay province – joined Turkey in a 1939 referendum whose integrity Syria still disputes.Hide Footnote Since 2016, Turkey has seized additional territory in Aleppo to pre-empt the YPG’s westward advance along Turkey’s southern border and deployed Turkish troops to observation points around rebel-held Idlib governorate. It remains unclear how or when Turkish forces will leave. For the regime, a Turkish invasion of north-eastern Syria could mean indefinitely ceding the Syrian territory richest with oil and wheat.

Turkish officials have only limited confidence in the Syrian regime’s ability or willingness to secure Syria’s Turkish border and neutralise what Ankara sees as a YPG/PKK threat. In Afrin, Turkey continued its offensive despite the entry of pro-regime paramilitary units into combat alongside the YPG.^[fn]See Crisis Group Report, Prospects for a Deal to Stabilise Syria’s North East, op. cit.Hide Footnote Still, the deployment of Syrian army forces along the north-eastern frontier could make Turkey think twice. Turkey may not be prepared to attack the official military forces of its sovereign neighbour, particularly if Russia extended these forces its protection.

The U.S. can play a salutary role in restraining Turkey as the SDF and Damascus negotiate. The U.S. has obvious coercive leverage over Turkey, such as the sanctions it deployed against Turkey to secure the release of detained pastor Andrew Brunson.^[fn]American pastor Jonathan Brunson was held in Turkey for nearly two years on espionage charges, eventually prompting the Trump administration to impose sanctions on Turkey to press for Brunson’s release. A Turkish court ordered Brunson’s release in October 2018. See Adam Goldman and Gardiner Harris, “U.S. Imposes Sanctions on Turkish Officials Over Detained American Pastor”, The New York Times, 1 August 2018; Carlotta Gall, “Turkey Frees Pastor Andrew Brunson, Easing Tensions With U.S.”, The New York Times, 12 October 2018.Hide Footnote But the Trump administration has also worked enough to repair bilateral ties with Turkey, including with measures like the Manbij “roadmap” and now the withdrawal from north-east Syria, to have generated some goodwill.^[fn]In June 2018, Turkey and the U.S. announced a “roadmap” for defining and implementing agreed-upon governance and security arrangements in the SDF-held eastern Aleppo town of Manbij. See Crisis Group Report, Prospects for a Deal to Stabilise Syria’s North East, op. cit. The two sides have since moved forward with the phased implementation of the agreement, although not always swiftly enough for Ankara’s liking. Turkish and U.S. officials, Crisis Group interviews, Ankara and Washington, November 2018.Hide Footnote Trump should use it to get Turkish agreement not to launch an attack in the north east. After Trump’s announcement, Turkey’s Erdoğan said he would delay any new military action.^[fn]“The phone call we made with Trump, as well as the contacts of our diplomatic and security units, and the statements made by the American side led us to wait for a while [for an operation east of the Euphrates river] …. Of course this is not an open ended waiting process". Turkish Prime Minister Recep Tayyip Erdoğan, “Turkey to delay operation east of Euphrates, Syria”, Anatolian Agency, 21 December 2018.Hide Footnote

Still, it is Russia’s genuine backing of an agreement that would be critical. Russia is well positioned to take into account both Syrian and Turkish concerns in that it supports a return of Damascus’ sovereignty over the entirety of the territory while also having an interest in maintaining strong ties to Ankara. In the earlier case of Afrin, Russia was unwilling to support a merely symbolic regime return that would have left the YPG in effective control and Turkey’s security concerns unaddressed.^[fn]In Afrin, Russia stressed to the YPG that only the full return of the regime, including its army and security services, could avert a Turkish attack. The YPG refused, and so Russia stood aside as Turkey invaded. The YPG’s counter-offer of a token Syrian military deployment on the border and the restoration of the symbols of the Syrian state, including flags, was not accepted by Damascus. By the time the Syrian regime decided to send Syrian military forces into Afrin in support of the YPG, Turkey was already mid-offensive and would not be deterred. Ibid.Hide Footnote This time could be different: as Russia did with Israel and Jordan in Syria’s south west earlier this year, it could work toward a solution that genuinely returns the north east to regime control while also meaningfully addressing Turkey’s security concerns.^[fn]Ahead of the Syrian regime’s offensive to retake Syria’s opposition-held south west, Jordan’s foremost concern was a rush of would-be refugees toward its border, while Israel was worried about Iranian-linked military units approaching the occupied Golan Heights and establishing a permanent presence. See Crisis Group Middle East Report N°187, Keeping the Calm in Southern Syria, 21 June 2018. Russia and the Syrian regime sequenced their offensive and pursued negotiated settlements with rebels in a way that dispersed an initial buildup of displaced people along the Jordanian border and then cut off the Jordanian border entirely as the offensive proceeded toward the Golan. Despite some unconfirmed reports to the contrary, there was seemingly no large-scale involvement by Iranian-controlled units in the offensive. Israeli officials now say that the Iranian-linked presence in the south west is at tolerable levels. According to one Israeli official: “It is very limited for now. Not a significant concern at present. We keep watching, of course”. Crisis Group interview, November 2018.Hide Footnote For neighbouring countries with non-existent or dysfunctional relationships with the Syrian regime, indeed, Russia appears prepared to be their interface with Damascus.^[fn]According to one Western diplomat: “It’s that way with everyone – the U.S., the Jordanians, the Arabs. Nobody wants to talk to the regime – wants to, or can. Everyone talks to the Russians because they can. How messed up is this situation that Russia is the moderate intermediary?” Crisis Group interview, Amman, October 2018.Hide Footnote

Whether Russia will be willing to argue on behalf of the SDF is a more difficult issue. In the south west, Russia has smoothed the return of the Syrian regime: deploying military police, mediating between state authorities and locals, and interceding to secure the release of individual detainees. But it has not stopped the regime in its tracks, or prevented the Syrian state from exercising sovereign control over Syrian citizens.^[fn]One Syrian aid worker said: “Even Russia doesn’t try to minimise the power of Syrian intelligence. The Russians say, ‘You’re a Syrian citizen, this is your government. It can do what it wants if it has something against you’”. Crisis Group interview, Amman, October 2018.Hide Footnote Given its ties to the SDF, Russia is likely interested in arranging preferential terms for it under restored regime authority – but preferential within limits, if the past is a guide.

Still, Russia’s interests would be served by helping Syria’s Kurds. Russia’s chief priority in Syria appears to be restoration of the Syrian state’s sovereignty over the entirety of Syrian territory. It has an incentive to prevent Turkey from taking over more of the country, including the north east, and to broker an arrangement for the SDF that allows the regime to return with minimal violence. In so doing, it could claim to have assisted all three constituencies and thus bolstered its regional position: Syria by allowing it to restore its sovereignty; Turkey by limiting the Kurds’ authority and denying them control of the Turkish border; and the Kurds by avoiding a military attack against them.

A U.S. withdrawal from Syria is not necessarily the wrong decision, or a trigger for lethal conflict; it is the “how” of that withdrawal that is acutely important. While another U-turn cannot be excluded, Trump seems to have set the U.S. on a course toward leaving Syria, but details remain unclear. There may yet be some flexibility on the move’s pace; any additional time, even limited, could allow the U.S. military and coalition allies to prepare an orderly exit.

In whatever time is left, the U.S. needs to do all it can to press and persuade Turkey not to launch an attack on SDF-controlled territory while allowing SDF-Damascus talks to proceed.^[fn]Crisis Group described the outlines of such a deal in Crisis Group Report, Prospects for a Deal to Stabilise Syria’s North East, op. cit.Hide Footnote The SDF fought alongside and on behalf of the U.S. to expel ISIS from its territorial seat, from which it plotted or at least inspired terror attacks worldwide. Abandoning the SDF would have lasting negative consequences for the U.S.’s ability to cultivate counter-terrorism partners; it would also be wrong.

Russia also should use what time it has to ensure the post-U.S. phase does not devolve into chaos. Russia should initiate talks with Turkey, the Syrian regime and the SDF aimed at effecting a transition in north-eastern Syria that would avert a violent free-for-all. This transition will likely require the return of Syrian regime forces to the Syrian-Turkish border as well as a political arrangement leaving Syrian Kurds with a measure of local self-rule.

Beirut/Brussels, 21 December 2018