The United States and Turkey Are on a Collision Course in Syria

An insider’s view on how we got here — and what Trump can do about it.

America’s relationship with Turkey has entered a period of deep crisis. At the heart of the matter is continued U.S. support for Syrian Kurds fighting the Islamic State. The partnership between the United States and a coalition of Kurdish People’s Protection Units (YPG) and Syrian Arab militias, currently known as the Syrian Democratic Forces (SDF), began more than two years ago under President Barack Obama. President Donald Trump’s administration continues to back the 50,000-strong SDF as the most capable anti-Islamic State force in northern Syria. The SDF are now closing in on Raqqa, the capital of the Islamic State’s self-described caliphate, and Trump has approved a plan to provide arms directly to the YPG for the final push. Yet Turkey sees the SDF as mortal enemies due to the YPG’s affiliation with the Kurdistan Worker’s Party (PKK), a designated terrorist organization which has fought a bloody insurgency inside Turkey for three decades. These clashing interests have put Washington and Ankara on a collision course just as the U.S.-led campaign to crush the caliphate enters its culminating phase.

Turkey’s concerns about the YPG are understandable and widely appreciated. What is less well known is the fact that it was Turkey’s own actions, in particular a set of decisions made by President Recep Tayyip Erdogan, that stymied joint U.S.-Turkey efforts to identify an alternative anti-Islamic State force. This pushed the United States and the YPG closer together and eventually created the SDF. And, with Raqqa in their sights, the Trump administration is unlikely to abandon them now.

In the closing days of the Obama administration, President Barack Obama was willing to increase training and assistance to the SDF, including YPG elements, for the final push on the Islamic State’s capital. But retired Lt. Gen. Michael Flynn, Trump’s incoming national security advisor, asked the administration to hold off so the new team could run its own review. (We now know that Flynn was paid to represent Turkish government interests prior to becoming national security advisor, although it is unclear whether that had any impact on the decision.)

After surveying the options, the Trump administration seems to have come to the same conclusion Obama did: the SDF represent the only viable force to seize Raqqa anytime soon. Nevertheless, the Trump administration decided to delay providing additional support to the SDF — especially armaments directly to the YPG — for months out of deference to the U.S.-Turkey alliance and Erdogan’s domestic politics. The hope appears to have been that waiting until after Turkey’s April 16 referendum on enhancing the power of the presidency would give Erdogan less incentive to whip up nationalist sentiment against the American plan. Following the narrow approval of the referendum consolidating Erdogan’s power, Trump even took the controversial step of calling Erdogan to congratulate him, most likely to make the bitter pill of the Raqqa operation easier to swallow. Erdogan was also invited to meet with Trump at the White House, a political boon to the Turkish president given rising international criticism over Turkey’s democratic backsliding.

It didn’t work. On April 25, Turkish warplanes struck YPG and PKK positions on both sides of the Syria-Iraq border. The bombing raid against a YPG command center on Mount Karachok in northeastern Syria — which occurred only a few miles from where U.S. troops were operating — killed 20 YPG fighters. Meanwhile, the Turkish strikes in northwestern Iraq, which targeted the PKK on Mount Sinjar, mistakenly killed several Kurdish Peshmerga troops instead. There was no formal coordination with the United States, and the U.S. military was given less than an hour’s notice prior to the Turkish operation. In the days since, U.S. forces have been patrolling the Syrian side of Turkey-Syria border, acting as de facto peacekeepers to deter the two side from going at each other’s throats.

Erdogan has warned that Turkey will continue to strike the YPG unless the United States abandons its partnership with them, even as Turkey has thrown its support behind a Russian proposal to create “de-escalation zones” to freeze the conflict elsewhere in Syria. One Erdogan advisor even hinted that U.S. forces could be struck if they continue to back the Syrian Kurds. If Turkey follows through with these threats, it could trigger a Turkey-Kurd border war that derails the Raqqa campaign, undermining a core national security interest of the United States. And, if a military mistake by Turkey results in the death of U.S. forces, it could bring Washington and Ankara — two NATO allies — into direct conflict.

When Erdogan travels to Washington next week, American support for the Syrian Kurds will be the top issue he raises with Trump. Erdogan is likely to urge Trump to cancel his decision to arm the YPG and look for other alternatives to take Raqqa — moves Trump is unlikely to take. Does that mean the two NATO allies are fated for an irreparable breach? No. But it does mean that, between now and then, the administration needs to develop a comprehensive plan to ease tensions, before it is too late. The campaign to defeat the Islamic State and the future of the U.S.-Turkey alliance hang in the balance.

Musa, a 25-year-old Kurdish marksman, stands atop a building as he looks at the destroyed Syrian town of Kobane, also known as Ain al-Arab, on January 30, 2015. Photo credit: BULENT KILIC/AFP/Getty Images

The Guns of September

Understanding the options available to the Trump administration requires understanding how we got to this point in the first place. The United States has made its fair share of mistakes in Syria. But the current predicament is largely the result of choices Erdogan made that pushed the United States to partner with the Kurds as the only viable anti-Islamic State force in northern Syria.

The story starts in September 2014, when Islamic State militants assaulted Kobani, a predominantly Kurdish border town under YPG control since 2012, pushing more than 100,000 refugees into Turkey. Turkey moved tanks to the border, but as the world watched jihadists lay siege to the city, Turkish forces refused to intervene on the YPG’s behalf. Kurds on the Turkish side were also blocked from entering Syria to help. Turkish officials saw Kobani as a fight between two terrorist entities, and Erdogan initially conditioned any Turkish assistance to the town on the YPG distancing itself from the Syrian regime, dismantling its administrative cantons in northeastern and northwestern Syria, and committing not to threaten the Turkish border.

In mid-October 2014, Obama authorized an air drop to provide Kurdish fighters desperately needed medical supplies and ammunition. Ankara and Washington then managed to broker an arrangement allowing Iraqi Peshmerga forces to transit Turkey into Kobani to help reinforce the YPG. (The Turks hoped that Iraqi Peshmerga forces aligned with Kurdistan Regional Government President Masoud Barzani would help counterbalance YPG influence.) Over the next three months, with the help of coalition airstrikes, thousands of Islamic State militants were killed and the YPG eventually succeeded in repelling the onslaught.

As the battle for Kobani raged, U.S. and Turkish officials began discussing the conditions for the U.S.-led coalition to gain access to Turkish air bases, as well as the extent of U.S.-Turkish cooperation to push the Islamic State off Turkey’s border. The U.S. Special Envoy for the Counter-Islamic State Coalition at the time, retired Gen. John Allen, and his deputy, Brett McGurk, worked up a proposal that would open up Turkish bases — which were already used by the United States for unarmed intelligence, surveillance, and reconnaissance (ISR) flights — for armed-ISR and strike missions against the Islamic State. The plan also included an ambitious joint U.S.-Turkish effort to identify, vet, train, and arm Syrian opposition forces, backed by U.S. and Turkish air power, to clear the Islamic State from the entirety of the Turkey-Syria border. There was even talk of introducing Turkish special operations forces as advisers to work alongside these fighters.

In late November 2014, I accompanied Vice President Joe Biden for two days of talks with Prime Minister Ahmet Davutoglu and President Erdogan in Istanbul (where Erdogan often preferred to hold meetings). The primary goal was to get the Allen-McGurk proposal, which had been worked on extensively with senior Turkish officials, across the goal line. In Biden’s meeting with Davutoglu, the vice president secured Davutoglu’s agreement to the joint plan. Biden then met with Erdogan, who clearly had different priorities. During nearly five hours of talks, Biden acknowledged Erdogan’s concerns over U.S. support to the YPG in Kobani, while noting that Turkey also supported highly problematic groups from the U.S. perspective, including Ahrar al-Sham, a powerful hardline Salafist force which often worked closely with al Qaeda’s Syrian affiliate. Biden urged Erdogan to put these differences aside by embracing the Allen-McGurk proposal. To address Erdogan’s concerns about the YPG, the United States and Turkey would identify an alternative, jointly vetted anti-Islamic State force. Erdogan was open to the proposal, but with one condition: the United States first had to impose a no-fly zone over all of northern Syria, including Aleppo city.

This was not a new request. For two years, Erdogan had pushed to establish a safe zone in Syria’s northern provinces of Aleppo and Idlib to stem the flow of Syrian refugees and provide an area for anti-Assad rebels to organize and train, backed by a no-fly zone to keep Assad’s planes at bay. Yet despite the threat being on Turkey’s doorstep, and the fact that Turkey possessed the most powerful land army and air force in the region, Erdogan was unwilling to directly intervene. Instead, he preferred that the United States take the lead in establishing these zones. The Obama administration’s campaign against the Islamic State, and the U.S. request for Turkish base access, was seen by Erdogan as useful leverage to achieve this longstanding objective.

Erdogan’s decision to play hardball stemmed from the priority he placed at the time on toppling Assad over combatting the Islamic State and other extremist groups. Indeed, for the first few years of the war, Ankara’s commitment to regime change led Turkey to impose few restrictions on the transit of anti-Assad fighters across the border into Syria. Even as the Islamic State spread in eastern Syria and the influence of al Qaeda’s Syrian affiliate grew among the northern opposition — including groups Turkey worked with — toppling Assad remained the focus of Erdogan’s policy.

Ultimately, Erdogan believed the specific threat the Islamic State posed to Turkey could be managed through a live-and-let live approach: if Turkey left the Islamic State alone in Syria, the Islamic State would not conduct attacks in Turkey. Erdogan therefore saw cooperation against the Islamic State as a favor to Washington, rather than something that was vital to Turkish national security. Thus he was intent on extracting a concession in return — namely, a commitment for the U.S. military to directly confront the Assad regime.

That condition proved to be a deal breaker. Imposing a no-fly zone would require the United States to take out Syria’s air defenses and shoot down Syrian aircraft. In the absence of a clear military end game, an international mandate, or domestic authorization, Obama was unwilling to enter into a direct conflict with the Assad regime. Moreover, the Pentagon told the president that a no-fly zone would require significant air and ISR assets to police it, directly trading off with the scarce resources needed for the anti-Islamic State campaign and operations in Afghanistan.

YPG women fighters stand near a check point in the outskirts of the destroyed Syrian town of Kobani, Syria. Photo credit: AHMET SIK/Getty Images

Turning Points

In the absence of U.S.-Turkey agreement, the Pentagon backed the only forces willing and able to take on the Islamic State in northern and eastern Syria: the YPG and affiliated Syrian Arab militias. After holding Kobani and regrouping, the YPG and their Arab allies went on the offensive in the spring of 2015. By mid-June they had seized Tal Abyad, one of two key Islamic State border crossings in northern Syria (the other being Jarabulus), gaining control of all but 60 miles of the Turkey-Syria border (see the maps below). Capturing Tal Abyad was particularly consequential since the Islamic State used the crossing to flow men, leaders, material, and explosive mixtures directly south into Raqqa, and often on to Iraq.

Map: Areas of Control, May 2015

(Source: Institute for the Study of War)

Map: Areas of Control, Late June 2015

(Source: Institute for the Study of War)

Meanwhile, Erdogan’s belief that Turkey could avoid being attacked by the Islamic State proved unfounded. On July 20, 2015, a bombing carried out by the Islamic State killed 33 people and wounded more than 100 in the southern Turkish city of Suruc. Many of the victims were Kurds. Several days later, PKK militants killed two Turkish policemen, claiming the attack as retaliation for Turkey conspiring with the Islamic State.

On July 22, 2015, following a phone call between Obama and Erdogan, Turkey agreed to open up Incirlik and other Turkish air bases to the U.S. coalition; strike missions began a few weeks later. Erdogan’s decision was prompted by the growing threat posed by the Islamic State. But, even more, it was motivated by Erdogan’s desire to check Kurdish expansion. Washington and Ankara agreed to work to identify vetted Syrian opposition forces to clear the Islamic State from the remaining 60 miles of the border not controlled by the Kurds — an area between the crossings at Azaz (in northwestern Syria) and Jarabulus (on the bank of the Euphrates River) known as the Manbij pocket. But Turkey was slow to identify opposition forces willing to prioritize fighting the Islamic State over Assad.The Pentagon’s “train-and-equip” program intended to stand up 5,000 opposition fighters per year struggled for the same reason, and had to be reoriented to focus on groups already combating the Islamic State on the ground. As a result, despite devoting nearly half of coalition ISR and strike missions flown out of Incirlik in this period to operations in the Manbij pocket, little progress was made.

In the face of these challenges, U.S. reliance on the YPG to combat the Islamic State continued to deepen. In October 2015, the Obama administration deployed a contingent of 50 U.S. special operations forces to improve training, planning, and support to Syrian Kurdish and Arab forces east of the Euphrates, who were rebranded as the SDF.

During another vice presidential trip to Istanbul in January 2016, Biden and other senior U.S. officials spent hours poring over maps of Iraq and Syria with Erdogan and his aides. Top on Biden’s agenda was conveying to Erdogan the urgent need to clear the Islamic State from Manbij City. The city was a key transit point for foreign fighters, a primary supply line to Raqqa, and a hub for Islamic State militants involved in external plotting. Indeed, U.S. officials believed that a number of the individuals involved in the November 2015 Paris attacks passed through Manbij. The U.S. proposal was to use the SDF to cross the Euphrates and push west to the city. But Ankara objected, seeing any SDF move into the Manbij pocket as a step toward unifying Kurdish cantons, and thus a geographic red line. In lieu of the SDF, Erdogan assured Biden that Turkey had thousands of opposition fighters ready to move east from the Azaz-Marea corridor area toward Jarabulus and then turn south to Manbij City.

The Obama administration agreed to hold off on using the SDF to work with Turkey. Yet only a few hundred Turkish-backed fighters materialized. In April, a small Turkish-backed force composed of Turkman, Free Syrian Army, and Salafist factions — supported by coalition air power — made a push to seize al-Rai (22 miles east of Azaz) and a number of other border villages moving toward Jarabulus. After some initial success, however, Islamic State militants regrouped and routed the Turkish-backed groups. On net, the operation lost ground.

With the Turkish play a bust, the United States once again swung behind the SDF alternative. In late May 2016, the SDF crossed the Euphrates headed toward Manbij City. After months of bloody battle, with thousands of casualties on both sides, the Islamic State stronghold fell to the SDF on August 12.

Two weeks later, Turkey finally discovered a larger opposition force and decided to intervene in Syria.

Turkish Army soldiers walk by tanks set to join a contingent for Turkey's operation Euphrates Shield on August 25, 2016. Photo credit: BULENT KILIC/AFP/Getty Images

Euphrates Shield

The Obama administration had promised that all YPG forces would move back east across the Euphrates following the liberation and stabilization of Manbij City. The failure of a small cadre of YPG to do so, as well as Ankara’s perception that the Arab-majority Manbij Military Council governing the city served as YPG proxies, heightened Turkish fears that Syrian Kurds might soon take over the rest of the border. The establishment of defensive positions by the SDF north of Manbij City, in proximity to Jarabulus, magnified this perception.

Compounding matters, in the aftermath of the attempted coup in Turkey in July 2016 by supporters of Fethullah Gulen, a Turkish cleric residing in Pennsylvania, relations between Ankara and Washington deteriorated further. A trip by Biden to Ankara in late August prevented the relationship from going completely off the rails, but serious tensions over the failure to extradite Gulen and continued U.S. support for the SDF persisted.

On August 24 (the same day as Biden’s visit), Turkish-backed opposition forces, supported by Turkish special operations troops and tanks, launched “Operation Euphrates Shield,” crossing into Jarabulus to push out the Islamic State and, most especially, contain the Kurds. As Turkish-backed forces moved south, quick intercession by the U.S. military and diplomats was required to narrowly avert a major clash with the SDF near Manbij City. Although Turkey had given the United States almost no warning of the operation, the Obama administration quickly offered U.S. special operations forces, ISR, and air support to Euphrates Shield, encouraging Turkish-backed militants to move west and southwest to clear Islamic State fighters from a string of additional border towns. After six months of fighting, Euphrates Shield culminated in the seizure of al-Bab, on the southern edge of the Manbij pocket, creating a 772-square mile buffer zone controlled by the Turks (see map).

Map: Areas of Influence, Early May 2017

(Source: Institute for the Study of War)

In many respects, Euphrates Shield represented the type of joint endeavor against the Islamic State first discussed in the fall of 2014. Yet it took nearly two years for Erdogan’s calculations regarding the Islamic State to shift sufficiently to justify direct Turkish intervention. More than anything else, however, Erdogan’s move was about the Kurds. In one of the many ironies of the Syrian war, it was Erdogan’s earlier reluctance to focus on the Islamic State that produced the very dynamic — close U.S.-YPG ties — that eventually forced Turkey’s hand.

Turkish President Recep Tayyip Erdogan and former Turkish president Abdullah Gul attend the funeral of a victim of the coup attempt in Istanbul on July 17, 2016. Photo credit: ARIS MESSINIS/AFP/Getty Images

Where Do We Go From Here?

Regardless of where one places the blame for the current predicament, we are where we are. The key question is: What can the Trump administration do about it?

Given the vital national interest the United States has in defeating the Islamic State, it would be unwise to abandon the SDF at this point, despite the frictions with Turkey. And it is hard to see the Trump administration doing so. During an April 26 event in Washington, for example, retired Lt. Gen. Terry Wolff, the current U.S. deputy special envoy for defeating the Islamic State, noted that the SDF represent the “only viable effort to liberate Raqqa.” He then added: “How long can you allow [the Islamic State] and its external operations to wait? We have a sense of urgency here.”

Not surprisingly, Turkish officials disagree. Erdogan will likely ask Trump to pause U.S. plans and reverse the decision to arm the YPG, arguing that the administration should support an assault on Raqqa utilizing thousands of Turkish-backed forces instead, essentially redirecting the groups mobilized for Euphrates Shield. Yet there is no such alternative force. The Pentagon estimates that the SDF totals 50,000 fighters, including 27,000 YPG and 23,000 Arab forces. In contrast, Turkey only marshalled a few thousand fighters for Euphrates Shield. Although some analysts believe that force may have now grown to perhaps 10,000-strong, they are needed to hold the buffer zone Turkey has created. And even if they could be freed up to assault Raqqa, their numbers remain too small — and the coherence and command-and-control of the motley assortment of groups too uncertain — to represent a credible alternative to the SDF for the foreseeable future.

Moreover, as a simple matter of geography, Turkish forces and the armed opposition groups operating in the Euphrates Shield buffer zone are boxed in, and it is unclear how they would even get to Raqqa. Moving south and east from the Euphrates Shield area in an attempt to hook up to Raqqa from the south would require them to fight through Russian and Assad regime forces. And if they opted to assault Raqqa from the north, it would require a permissive corridor through SDF lines, which is hard to imagine, or seizing the Tal Abyad crossing and then fighting through thousands of American-backed Kurdish and Arab fighters, which would be disastrous (see the map below.)

(Image credit: Institute for the Study of War)

Nor would it be a good idea to substitute American G.I.s for the SDF in an effort to appease Turkish concerns. Last month, reports surfaced that senior National Security Council staff floated the option of sending tens of thousands of U.S. troops to Syria to seize Raqqa. Such a move, which would essentially represent an invasion of Syria, would be a major departure from the “indirect approach” that relies on local partners to seize and hold terrain. Beyond the costs in American lives, it would leave the U.S. military owning a Syrian city with more than 200,000 inhabitants with no exit strategy. It should come as no surprise that the Pentagon is not a fan of this option, and Trump has recently reiterated his desire to avoid sending large numbers of U.S. ground forces into combat against the Islamic State, as well as his reluctance to sink further into a Syrian quagmire.

Given the paucity of good alternatives, the Trump administration should move ahead with the SDF option. But it should do so as part of a broader strategy aimed at mitigating Turkey’s concerns as much as possible. Such a plan should include at least five elements.

First, even as Trump impresses upon Erdogan the urgent need to liberate Raqqa with the forces at hand, the administration needs to make a stronger case — both in private and in public — for the potential advantages to Turkey of the U.S. partnership with the YPG. The Raqqa operation orients the SDF away from the Turkish border and away from further attempts to link Kurdish cantons. American backing also provides important influence over YPG cadre in north central and northeastern Syria, limiting the prospect that the YPG will pursue an alternative alignment with Russia and Iran, which could prove much more detrimental to Turkish interests.

The U.S. relationship with the YPG and its political wing, the Democratic Union Party (PYD), also positions the United States to potentially play a quiet mediating role between Turkey and the PKK in the event the parties are willing to re-start peace talks. This is something that should be in Erdogan’s interest given the toll the PKK insurgency has taken on Turkish society, and the fact that there is no purely military solution to the conflict. Moreover, having consolidated executive power, Erdogan’s political need to whip up anti-Kurdish sentiment should theoretically be lessened. It is important to remember that, from 2012 to early 2015, Erdogan previously pursued a strategy that aimed to end the war with the PKK via a negotiated settlement. Simultaneously, the Turkish government engaged the PYD/YPG in the hopes of driving a wedge between them and the PKK. This strategy collapsed in 2015 as the cycle of PKK violence reignited and Erdogan’s own political interests in checking Kurdish political gains in Turkey led him to take a harder line. One key task for Trump, therefore, is to make the case to Erdogan that it is in Turkey’s interest to return to a version of this earlier approach — and that the U.S. dealmaker-in-chief is prepared to help.

Second, to address Ankara’s concerns that U.S. assistance to the YPG could produce a direct military threat to Turkey, Trump should commit to being fully transparent with Erdogan about the nature of the military support the United States is providing to the SDF. U.S. defense officials have said the assistance will include small arms, machine guns, ammunition, armored vehicles, and engineering equipment. The administration should follow through with a Pentagon proposal to meter the quality and quantity of the weapons and ammunition it provides to YPG forces such that it enables the Raqqa operation while posing as little danger to Turkey as possible. And the administration should present a credible mechanism to track weapons provided to the YPG so they do not end up across the border in the hands of the PKK. Any heavy weapons provided should also be returned to the United States following the Raqqa campaign.

Third, Trump should outline a broader modus vivendi between Ankara and the SDF that, while far from ideal from Erdogan’s perspective, would preserve core Turkish interests in containing Kurdish ambitions and sustaining the U.S.-Turkey alliance. The Trump administration must define and enforce clear and credible limiting conditions on the expansion of the Kurds’ territorial control and influence in Syria. In practice, that means the United States should be willing to deliver a total SDF withdrawal across the east bank of the Euphrates, leaving Manbij City to be administered by groups acceptable to Turkey. It also means providing additional U.S. assistance to Turkey’s efforts to consolidate its Euphrates Shield buffer zone — both as a hedge against the return of the Islamic State and to ensure that the Kurds do not link their cantons and control the entire Turkey-Syria border. The administration should restate U.S. opposition to an independent Kurdish state in northern Syria. And it should push for the inclusion of non-PYD and non-Kurdish political organizations Turkey can live with in SDF-administered areas east of the Euphrates, including in Raqqa once the city is liberated.

Furthermore, it is imperative that Trump does more to reassure Erdogan that the United States continues to regard the PKK as a terrorist organization, offering more intelligence and assistance to head off PKK attacks. To further address Turkish security concerns, the administration should make it crystal clear to the YPG that a continued operational relationship with the PKK — especially in the context of ongoing PKK attacks in Turkey — will make any long-term, post-Raqqa relationship with the United States unviable.

Even as it takes steps to address legitimate Turkish concerns, however, Trump must insist that Erdogan take reciprocal actions to address the concerns of Syrian Kurds. If the SDF fully withdraws east of the Euphrates, for example, Turkey should facilitate the creation of a secure transportation corridor across its buffer zone to allow the movement of Kurdish civilians between disconnected Kurdish cantons. In exchange for greater participation of openly pro-Turkish political organizations in SDF-controlled areas, Turkey should also agree to tolerate a future Syrian government that provides a degree of local autonomy to SDF-controlled areas in northern Syria. And, in return for the YPG distancing itself from the PKK, the Trump administration should offer the SDF continued U.S. assistance.

Finally, Trump should be prepared to present options to address Erdogan’s concerns regarding the PKK outside of Syria, especially in northern Iraq. Erdogan is very worried about the presence of the PKK in the Sinjar mountain region, one of the areas bombed on April 25, fearing that the PKK will work with Iran to establish a “land bridge” to ship weapons from Iran to Syria via Iraq. Here, the United States has unique influence with all the relevant parties, and Trump should offer to use that influence. As a recent International Crisis Group report usefully suggests, the administration could potentially leverage U.S. relationships with the YPG, Iraqi Kurdistan President Barzani, and Iraqi Prime Minister Haider al-Abadi to remove the PKK from Sinjar. Trump could also offer to intercede with Baghdad, warning Abadi that attempts by Iranian-backed Shiite militia to build a land bridge into Syria could prompt a military confrontation between Iraq and Turkey and complicate the long-term military partnership Abadi seeks with the United States after the fall of Mosul.

None of these actions represent a silver bullet. And none will be an easy sell for Erdogan. No amount of reassurance or compensation by the Trump administration will lead Turkey to accept the U.S. relationship with the YPG. But, taken together, the steps suggested here may be just enough to prevent the campaign against the Islamic State and the U.S.-Turkey alliance from sliding into the abyss — something that should be in the interest of both countries.

As with many of the global challenges Trump faces, the president is undoubtedly discovering that events in northern Syria are complicated. Indeed, there may be no more complicated piece of terrain on the planet. But with U.S. forces caught in the middle of escalating Turkey-Kurd tensions and Erdogan’s impending arrival to Washington, the president has no choice but to grapple with this complexity. Fast.

Top photo credit: DELIL SOULEIMAN/AFP/Getty Images

Colin H. Kahl is an associate professor in the security studies program at Georgetown University’s Edmund A. Walsh School of Foreign Service and a strategic consultant at the Penn-Biden Center for Diplomacy and Global Engagement. From 2014 to 2017, he was deputy assistant to President Barack Obama and national security advisor to Vice President Joe Biden. From 2009 to 2011, he served as the deputy assistant secretary of defense for the Middle East. In 2011, he was awarded the Secretary of Defense Medal for Outstanding Public Service by Secretary Robert Gates. He lives in Washington, D.C. with his wife and two children. Kahl is a co-editor of Shadow Government. (@ColinKahl)