Executive Summary Tough talk notwithstanding, the Trump administration’s early actions in Iraq and Syria appear broadly consistent with the approach pursued by the Obama administration. The United States will continue to work by, with, and through local partners in Syria to defeat and destroy the Islamic State in Iraq and Syria’s (ISIS) self-described caliphate, conduct counterterrorism operations against al Qaeda and its allies in Syria, and minimize America’s investment in western Syria’s more complex civil war. To be sure, there are some meaningful shifts. In the counter-ISIS fight, the new administration seems willing to take greater risk and put U.S. forces closer to the fight in Iraq and Syria, and it has thus far put much less emphasis on humanitarian assistance, reconstruction, and economic aid to areas liberated by ISIS than the Obama administration did. Moreover, President Donald J. Trump’s decision to conduct cruise missile strikes against the Assad regime’s al-Shayrat air base in response to Assad’s April 4 chemical weapons attack against civilians was a significant development, standing in contrast to President Barack Obama’s 2013 decision to pursue a diplomatic solution following Assad’s previous use of deadly gas. Nevertheless, despite confusing rhetoric coming from Trump administration officials, Trump’s decision to strike mostly signified an attempt to deter the future use of chemical weapons rather than a fundamental strategic change in policy toward Assad or the Syria war more generally. Fundamentally, the biggest challenge the Trump administration will face in Syria is the same one the Obama administration faced: how to end the devastating civil war that has been at the root of so many of the problems emanating from Syria and Iraq over the past six years. Indeed, only through a negotiated agreement that ends the conflict can the United States achieve its core objectives in Syria: eliminating ISIS and al Qaeda safe havens, and protecting its Middle Eastern and European partners from the destabilizing dangers posed by foreign fighters and refugee flows. A framework to de-escalate and settle the Syrian conflict has eluded the international community for years, but recent developments on the ground have created an opportunity to move toward a viable and sustainable end state. Syria has fragmented into several distinct “zones of control,” each governed by different local players and heavily influenced by various external powers—including a growing U.S. zone of influence in northern and eastern Syria in areas liberated from ISIS. This fragmentation has provided the foundation for a tentative cessation of hostilities brokered by Russia, Turkey, and Iran that has at least reduced violence in some areas. With deft diplomacy, the Trump administration may be able to leverage growing U.S. influence in formerly ISIS-controlled territory to broker a broader national cease-fire and eventually a negotiated political solution. This option would defer the question of Assad’s fate but would avoid the breakup of the Syrian state and de-escalate the conflict through a governing system where most of the power is devolved outside of Damascus. The biggest challenges in negotiating a cease-fire and political agreement based on emerging zones of control include resolving tensions at the seams of these zones, working out a mechanism to coordinate counterterrorism operations against groups not covered by the cease-fire, and gaining international and regional buy-in for a political settlement that decentralizes power but leaves the Assad regime in place. If the Trump administration pursues the approach described here, critical tasks will include: Forging an agreement between America’s Turkish allies and Kurdish partners to continue the momentum against ISIS, while establishing the foundation for long-term peace and stability in northern Syria.

Establishing a counterterrorism-coordination mechanism—beyond current de-confliction efforts—with Russia, while insisting on conditions that alter Moscow’s approach to military operations and restrain Assad and Iranian-backed groups.

Engaging Iran to gain Tehran’s buy-in to a de-escalation and decentralization framework and reduce the prospects of military miscalculation between the United States and Iran.

Securing support from Israel and America’s Gulf partners through enhanced efforts to push back against Iran elsewhere in the region.

Syria's Zones of Control Any attempt to de-escalate the Syrian war and reach a political settlement must begin with an acknowledgement of changing dynamics on the ground. Developments on the overlapping battlefields of the counter-ISIS and anti-Assad campaigns in Syria have effectively fragmented Syria into six distinct zones: Assad’s statelet; al Qaeda’s northwestern haven; northern Syria, divided between Turkey and the Kurds; ISIS-held eastern Syria; a moderate opposition buffer supported by Jordan and Israel in the southwest. Assad’s Statelet Bashar al-Assad rules over a multi-factional statelet centered in the coastal and west-central region of the country that includes Damascus, Aleppo, Latakia, Homs, and Hama. This area is greatly influenced by both Russia, which is supporting Assad via air power, and Iran, which is on the ground through Iran’s Islamic Revolutionary Guard Corps (IRGC), Hezbollah, and other Shia militias from Iraq, Pakistan, and Afghanistan that it has imported into the country. For the foreseeable future, Russia and Iran are deeply invested in the continued survival of Assad as the leader of Syria, and both countries have been closely coordinating their pushback against the Trump administration’s recent statements on his future. Assad’s statelet is the base for both Russia and the IRGC to pursue their strategic goals in the Levant, although it remains unclear to what extent Russian and Iranian objectives will diverge in Syria as time wears on.

Al Qaeda’s Northwestern Haven The northwest is the most complex part of the country. Areas north and west of Aleppo are edging toward another humanitarian disaster due to military pressure from the Assad government and its allies, principally aimed at the opposition bastion in Idlib province. Notably, this was the location of the April 4 chemical attack that killed approximately 80 civilians and prompted the Trump administration two days later to strike the airfield from which the attack was launched. Simultaneously, Idlib is at risk of becoming an al Qaeda haven. In Idlib, the moderate armed opposition movement is fragmented and the revolutionary movement is being shaped by two main blocs: Hayat Tahrir al-Sham, dominated by the Syrian al Qaeda affiliate (formally known as Jabhat al-Nusra but rebranded as Jabhat Fateh al-Sham), and Ahrar al-Sham, a militant Salafist organization. Ahrar al-Sham, which the Department of State recently declared a “loyal defender of the Syrian revolution,” is a highly problematic actor because it was nurtured by global jihadist operatives close to al Qaeda and it is often compared to the Taliban. Because of its close ties to Turkey, Ahrar al-Sham will continue to be a major, long-term power broker in northwestern Syria. Meanwhile, beginning in the last year of the Obama administration and continuing under Trump, the United States has conducted an increasing number of airstrikes against al Qaeda or its close partners in northwestern Syria, demonstrating U.S. officials’ growing concern that the region could become an eventual platform for al Qaeda attacks against American interests. Some of these U.S. strikes in Idlib have reportedly led to significant civilian casualties due to the integration of al Qaeda fighters into Hayat Tahrir al-Sham and the local Syrian communities that it controls or influences. The overlap between regime actions Washington opposes and groups hostile to U.S. interests creates significant complexities for U.S. policy in northwestern Syria, particularly Idlib province. In any end state, this area will have to be retaken; it cannot exist in perpetuity under the control of al Qaeda or groups closely aligned with al Qaeda. Northern Syria, Divided Between Turkey and the Kurds North and east of Aleppo, Turkey, with the assistance of the U.S.-led coalition, has carved out a sizable area of control through the intervention of its military and Syrian opposition affiliates. The goal of this effort is to push ISIS from Turkey’s border while preventing Syrian Kurdish expansionism. This area is essentially acting as a buffer zone agreed to by all the parties (including Russia and, tacitly, Assad) and will likely remain under Turkish control for the foreseeable future. The Turkish effort, however, is running in competition with the U.S.-backed Syrian Democratic Forces (SDF), composed of Kurdish-majority People’s Protection Units (YPG), many of which have ties to the Kurdistan Workers Party (PKK) that Turkey considers to be a terrorist group, and various Arab militia known as the Syrian Arab Coalition (SAC). These local Syrian partners undergird an expanding zone of control for the United States and its coalition partners throughout areas of northern and eastern Syria that have been taken from ISIS. Through their dueling counter-ISIS campaigns, the United States and Turkey are establishing separate military mandates over a significant area of Syrian territory. Managing this competition and negotiating an outcome acceptable to both the Turks and the Kurds will be one of the toughest challenges moving forward, as demonstrated by the recent Turkish strike on U.S.-backed YPG forces operating near the Syria-Iraq border. Yet it is hard to see a scenario in which a large portion of northern and eastern Syria does not remain under the control of the Kurds and their partners via a semi-autonomous federal province of northern Syria.

ISIS-Held Eastern Syria ISIS’s would-be caliphate is contracting, but remnants of the Islamic State are likely to pose a challenge in eastern Syria for or the foreseeable future. A central question remains over who will lead the effort to retake the ISIS capital of Raqqa: the U.S.-backed SDF coalition, with its heavy Kurdish component; Turkey’s handpicked Syrian opposition forces, which include militant Islamist organizations such as Ahrar al-Sham that are problematic for the United States; thousands of U.S. forces engaged in direct combat; or Assad’s forces, backed by Russia and Iran. Given the SDF’s proximity to Raqqa and its current battlefield momentum, the difficulty of Turkey’s marshalling a credible alternative, President Trump’s reluctance to introduce large number of U.S. forces, and Assad’s focus on other parts of the country, the most likely outcome is a U.S.-backed SDF offensive comprising thousands of Kurdish and Arab fighters. But it remains to be seen what mix of actors will hold and govern Raqqa after it is liberated, and it is possible that several parties will play some role. Further south, in the governorate of Deir al-Zour, near a key border area with Iraq, the question of who retakes territory becomes even more challenging, as there are profound strategic implications for the Assad regime and Iran. There are already signs that ISIS is relocating key commanders and leaders to Deir al-Zour, and this process is likely to accelerate as the final battle for Raqqa commences. Therefore, after Raqqa’s liberation, the question of who seizes Deir al-Zour will surface as a major concern.

It remains to be seen what mix of actors will hold and govern Raqqa after it is liberated, and it is possible that several parties will play some role.

The Assad regime and its backers are significantly invested in the area because of the region’s economic importance to the regime due to the oil and gas resources in this region, and Assad’s forces have long maintained a besieged outpost in Deir al-Zour. They are unlikely to cede this territory to other anti-ISIS forces. Moreover, the Iranians may seek to create a “land bridge” that stretches from Iran across Iraq and Syria into Lebanon by using Deir al-Zour governorate. and the Syrian Desert region to link Southern Iraq and the central and western parts of Syria that Assad currently controls. At the same time, the United States and its partners may have several options for retaking this territory. If U.S.-backed SDF partners retake Raqqa, they could move south to the Euphrates River valley and Deir al-Zour. The United States and its regional partners (most notably Jordan) have relationships with other local Syrian forces near Deir al-Zour and in the Syrian Desert region. These forces, potentially in collaboration with U.S.-supported tribal forces on the Iraqi side of the border, might be able to preclude the potential Iranian land bridge. A Moderate Opposition Buffer for Jordan and Israel in the Southwest Finally, the southwest is dominated by the moderate Southern Front opposition coalition, supported by Jordan and, indirectly, by Israel. This area acts as a buffer both for keeping the IRGC off Israel’s border and preventing the flow of extremists from destabilizing Jordan. The IRGC is actively seeking to challenge Israel’s control over the Golan Heights by expanding its presence and that of its proxy Shia militias in Syria’s Quneitra province. Some Sunni extremist groups, particularly ISIS, continue to operate in the area, and the U.S. objective should be to help the Southern Front consolidate control while ensuring that in any agreement it remains responsible for security and governance of this territory.

Turning Fragmentation Into a Political Solution Six years of grinding war has left Syria a deeply fractured country. Yet this very fragmentation provides an opportunity for the Trump administration to work with Russia and key regional states to de-escalate the conflict and reach an enduring political settlement. In a series of RAND reports, James Dobbins, Philip Gordon, and Jeffrey Martini have presented a formula for de-escalating the Syrian war by freezing the fighting and working toward a political framework that could be acceptable to the major Syrian and foreign actors that are most invested in the conflict. Building on this approach, the authors recommend that the Trump administration pursue a two-phased strategy. First, the administration should capitalize on emerging zones of control to produce a durable national cease-fire. Altered dynamics on the ground have already provided the foundation for the fragile cessation of hostilities in western Syria brokered and managed by Russia, Turkey, and Iran via the “Astana Process.” And it may be possible to build on the May 4th Russian, Turkish, and Iranian agreement at Astana to create geographically delineated “de-escalation zones” in northern Syria (parts of Idlib, Aleppo, Lattakia, Hama), central-western Syria (east of Damascus and an enclave north of the city of Homs), and southern Syria (still undefined) to craft a more durable resolution to the conflict.

The administration should capitalize on emerging zones of control to produce a durable national cease-fire.

The Trump team—which has thus far generally remained aloof from Syria diplomacy—should now fully engage, taking advantage of the influence it derives from the U.S.-managed territorial zone of influence in northern and eastern Syria. The goal should be to end the fighting between the Assad regime and the moderate opposition, with the major foreign actors in each zone of control being primarily responsible for enforcing the cease-fire, providing security, and ensuring unfettered distribution of humanitarian assistance. Moreover, as fighting between Assad and the opposition subsides, all actors to the conflict should agree to focus on defeating terrorist organizations that fall outside the cease-fire and the zones they control, namely ISIS and al Qaeda. Such an arrangement would be consistent with the Trump administration’s counterterrorism priorities while potentially helping to produce the “interim zones of stability” that Secretary of State Rex Tillerson alluded to during a March meeting of foreign ministers from the 68-nation counter-ISIS coalition. Once a national cease-fire is in effect, the second phase of this strategy should focus on negotiating a political settlement that reflects the current realities on the ground. The arrangement would keep Assad in power, at least for some period of time, but decentralize power away from Damascus (and Assad) to allow opposition groups considerable control over local security and governance. While the opposition and its backers would clearly prefer a near-term transition away from Assad altogether, it is hard to see the United States and its allies mustering sufficient military pressure on the regime or its backers to force such an outcome. Indeed, the April 6th U.S. cruise missile strike and hardened administration rhetoric notwithstanding, Trump appears to have little appetite for confronting Assad directly—and, even if the administration decided to increase pressure on the regime, it is not at all clear pressure would work, given Russian and Iranian commitments to sustain Assad in power. A more realistic approach, therefore, would leverage the exhaustion of all the parties, the inability of the regime to retake the entire country, and the shifting calculus of regional states more concerned with combating terrorism than unseating Assad to press the regime and the opposition to accept a decentralized arrangement. Achieving such an agreement will not be easy. It will require the Trump administration to resolve tensions at the seams of existing zones of influence, to bargain shrewdly to establish coordinated counterterrorism activities with Russia while restraining the Assad regime, and to secure international and regional buy-in for a political settlement that decentralizes power but leaves Assad in office. Pulling this off will entail concerted U.S. diplomacy to manage conflicting interests on the ground, as well as the creative deployment of American military and financial leverage. Brokering a Turkish-Kurdish Arrangement in Northern Syria The first step in this process will be for the United States to get on the same page with its Turkish and Kurdish partners. Turkey is acting to counter the PKK in Kurdish areas of Syria and Iraq and worries that the United States is enabling an independent Kurdish state. The Turkish military’s April 25th airstrikes against YPG positions in northern Syria and northwestern Iraq have further complicated the situation and could signal an escalation. The United States responded to Turkey’s bombardment with military patrols along the Syria-Turkey border and a show of strong support for local Syrian Kurdish partners to deter further Turkish strikes. In essence, this has put the United States in near conflict with a NATO ally. Turkey has set the Euphrates River in northern Syria as the red line for the westward expansion of the Kurds, fearing a consolidated Kurdish state that runs across Turkey’s entire southern border. The town of Manbij, which was taken by the SDF last summer and where U.S. forces are currently deployed to act as peacekeepers, has become a flashpoint for the running Turkish-American argument over the Syrian Kurds. Turkey views the SDF control over Manbij as a threat; the United States argues that Kurdish elements of the SDF have withdrawn to the eastern bank of the Euphrates and that Turkey is creating an unnecessary crisis that severely distracts from the impending operation to seize Raqqa.

To reassure Turkey, the United States will have to demonstrate to Ankara that it will 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 must be willing to deliver a total SDF withdrawal to the east bank of the Euphrates and push for the inclusion of political organizations Turkey can live with in the de facto autonomous administration of SDF-controlled areas of northern and eastern Syria.

Even as it takes steps to address legitimate Turkish concerns, the United States must insist that Turkey take several steps that are important to Syrian Kurds and their allies in the SDF in return.

The Trump administration should also make clear that it will withdraw American support if Kurdish political parties in SDF-controlled areas do not take steps to distance themselves credibly from the PKK. The recent decision authorizing the U.S. military to provide weapons, ammunition, and vehicles directly to the Kurdish-majority YPG to support the Raqqa campaign could provide greater U.S. leverage on the Kurds. However, the decision also raises serious tensions with Turkey as the coalition prepares to support the SDF to capture Raqqa from ISIS, and to hold and administer the city afterwards. Even as it takes steps to address legitimate Turkish concerns, the United States must insist that Turkey take several steps that are important to Syrian Kurds and their allies in the SDF in return. In exchange for the SDF’s withdrawal 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 agree to support a decentralized future Syrian government that would give significant local autonomy to SDF-controlled areas in northern and eastern Syria. In exchange for the YPG’s disavowal of the PKK, the Trump administration should offer the SDF continued U.S. assistance. Tough Bargaining with Russia and Iran The United States will also have to come to an arrangement with Russia and Iran to eliminate the remaining ISIS and al Qaeda safe havens. The key here will be an understanding with Russia, whose air support remains critical for Assad’s ability to retake territory. However, because of Moscow’s abhorrent behavior since its intervention in September 2015, any such arrangement must come with substantial strings attached. And indeed, in the wake of the chemical weapons attacks in Idlib, U.S.-Russian cooperation should be considered a nonstarter unless significant restraints are placed on Assad. One priority should be to formalize the currently de facto mechanisms for military de-confliction between Russia and Assad, on the one hand, and the United States and Turkey, on the other, to manage hostilities in core ISIS areas that remain unconquered. Future flashpoint areas that could cause conflict between Russia and Assad and the United States are in and around Raqqa and farther east in the lower Euphrates River valley, in and around Deir al-Zour. The decision on who takes and holds this territory will likely be dictated by military realities. The future administration of both core areas of eastern Syria should be determined in coordination with Russia. Russian agreement will also be key to clearing al Qaeda–held territory in Idlib; however, the Trump administration should cooperate with Moscow only under strict conditions. The key is to separate the moderate opposition from extremist elements and bring discriminate force to bear only on the latter. The Astana “de-escalation zones” deal requires Assad’s forces to refrain from flying over the designated areas, but provides a loophole for continued operations against “terrorists” (which the regime has historically defined as the entire opposition). If Assad’s air force continues to fly under the current arrangement, Washington must insist that those planes be grounded, without exception, before cooperating with Moscow. Therefore, in addition to maintaining its commitment to strike Assad if the regime uses chemical weapons again, the Trump administration should seek a Russian-American agreement to stop Assad’s indiscriminate air strikes against the remaining opposition-controlled areas in northwest Syria (as well as in southwestern Syria and around Damascus). The administration should also push Russia to hold back Iranian-initiated ground offensives in these areas. In exchange, the Trump administration could commit to leading and coordinating with Turkey, Jordan, Qatar, and Saudi Arabia to pressure the armed opposition in these areas to distance themselves from and, where possible, confront extremist groups, particularly the al Qaeda front Hayat Tahrir al-Sham. The Trump administration could also agree to share targeting information with Russia against extremist groups, but only if Moscow provides credible commitments to align air operations with the laws of war and to give Washington veto rights over targets; and U.S. support should be quickly withdrawn if Russia continues to bomb civilians. When the Obama administration attempted to negotiate similar conditions last fall, Russia proved unwilling or unable to meet them. The same may hold true today. However, given Russia’s desire for closer cooperation with the Trump administration, and the incremental leverage produced by the April 6th cruise missile strike and international outrage over Assad’s behavior, the Trump team should retest the proposition. Moreover, whereas the Obama administration’s attempt to broker a cooperative framework with Russia proved untenable in the context of the battle for the strategically vital city of Aleppo, Moscow places much less importance on Idlib and therefore may now be more willing to accept operational constraints in exchange for counterterrorism cooperation with Washington.

Russian agreement will be key to clearing al Qaeda–held territory in Idlib; however, the Trump administration should cooperate with Moscow only under strict conditions.

Getting Russia to buy into these operational constraints and to pressure Assad into accepting a decentralized political arrangement will require the Trump administration to engage in tough bargaining and disciplined insistence on strict conditions for any U.S. cooperation. The effort may not work, but anything less would risk American complicity in continued atrocities committed by the Assad regime and its backers, worsening Syria’s humanitarian crisis and pushing more of the opposition into the hands of al Qaeda. Fortunately, the administration still possesses important military and financial leverage. Although President Trump often talks about the benefits of cooperating with Russia to defeat ISIS, the reality is different: the United States does not need Russia to crush the caliphate. On the contrary, it is Moscow that desperately wants American counterterrorism cooperation, to legitimize Russia’s intervention. This gives Trump an advantage for negotiating strict conditions on any such cooperation. The new administration’s willingness to use force—even if only in a highly-limited way—and Trump’s unpredictability could further improve U.S. leverage by suggesting Russian interests could be undermined in the absence of a cooperative framework. The Trump administration also has enormous financial leverage—although taking advantage of this leverage will require the president to move away from his rhetorical allergy to nation building. Rough estimates suggest that hundreds of billions of dollars will be required to rebuild Syria. Absent concerted efforts by the United States, working alongside the United Nations, the European Union, and wealthy Gulf states, the regime and its backers will be left holding the bag. This gives the Trump administration and its allies tremendous power to shape the outcome of the Syrian conflict, if they are willing to use it. The deep cuts Trump has proposed to the State Department and the U.S. Agency for International Development budgets suggest that he places little value on foreign and humanitarian assistance. Yet the offer to work with the international community to raise money to rebuild Syria should not be charity—it should be viewed as a strategic imperative. It is the only way to prevent extremists from re-emerging from the rubble of liberated areas. And, because it gives the administration a major chit to play in negotiations, it is something that should appeal to the dealmaker in Trump. Engaging Iran Resolving the Syrian war will require President Trump to move beyond his comfort zone in another respect: the Trump administration will have to talk to Iran. Trump has railed against the Iran nuclear deal and put Iran “on notice” for its ballistic missile tests and other destabilizing behavior. And both Secretary of State Tillerson and Secretary of Defense Jim Mattis have made clear publicly that they intend to draw a hard line regarding Iran’s destabilizing behavior in the region. The president has shown no appetite to resolve tensions with Tehran through dialogue—but in Syria, he has little choice.

Getting Israel and Gulf Partners on Board Outreach to Iran will unsettle some of America’s regional partners, especially Israel, which worries about growing IRGC influence along its border, as well as Saudi Arabia and other Gulf states that have supported the opposition in Syria in large part to blunt and bleed Iran. But there are options to address Israeli and Gulf state concerns about Iran that could potentially secure their buy-in to the de-escalation and decentralization framework proposed here. While pushing Iran out of Syria altogether is not practical, there are areas where the United States could work with its partners to reduce Iranian influence in the Levant and the Arabian Peninsula as a means of reassuring Israel and the Gulf states. There are a number of steps the United States could take to complicate Tehran’s efforts to threaten Israel and construct a land bridge linking Iran to Lebanon via Iraq and Syria. Instantiating the buffer zone in southern Syria could help keep the IRGC off Israel’s border and empower moderate opposition forces in the south to target Sunni extremists who might otherwise threaten Israel or the stability of Jordan. (The Gulf states would also be reassured by any effort to bolster Jordan’s stability.) The Trump administration could further address Israeli concerns through enhanced intelligence cooperation aimed at thwarting the transfer of advanced Iranian weapons systems across the Syrian border to Hezbollah in Lebanon.

The Trump administration could also be more assertive in pushing back against Iranian influence on the Arabian Peninsula.

Simultaneously, the United States should encourage and enable anti-ISIS forces in Syria to pivot toward Deir al-Zour and the lower Euphrates River valley after Raqqa is liberated, to counterbalance an Iranian bid to dominate the area. On the Iraqi side of the border, the Trump administration should commit to remain engaged in supporting the Iraqi government beyond the defeat of ISIS in Mosul. This does not mean picking a major fight with the Iranians in Iraq, which would be foolish and costly. But maintaining American influence in Iraq could partially offset Iranian influence and enable Washington to press the Baghdad government to limit the flow of Iranian arms through Iraq into Syria. None of these checks are absolute or ideal, but they could significantly limit Iran’s ability to project power into the Levant, thereby easing some Israeli and Gulf anxieties. The Trump administration could also be more assertive in pushing back against Iranian influence on the Arabian Peninsula. Although the United States should avoid direct military intervention into Yemen’s civil war, and caution Gulf allies against moves that worsen the country’s humanitarian crisis, the administration could offer additional U.S. cooperation to interdict and disrupt Iranian support for Houthi militants in Yemen—a form of Iranian influence that much more directly affects Saudi and Emirati interests and is of lesser priority to Iran. The Trump administration could combine these steps with commitments to expand efforts begun under Obama to enhance Gulf military capabilities—especially in areas such as special operations, maritime and missile defense, and cyber operations—to counter Iran’s asymmetric capabilities and influence throughout the region. In exchange, the Trump administration should secure Gulf Arab state commitments to support a de-escalation and decentralization framework in Syria and back away from the demand that Assad immediately depart. The Trump administration should also expect Gulf states to contribute more to counterterrorism operations and, crucially, to contribute substantial humanitarian and reconstruction assistance to support stabilization efforts in Syria and prevent the re-emergence of ISIS or other extremist groups—requests Trump has already raised with the Saudis and others. Achieving a Political Framework for the Endgame in Syria Once these regional agreements are in place and external actors including Turkey, Russia, Iran, Saudi Arabia, and other key states have had their core interests met, it may be possible to move on to a national political agreement that ends the conflict. Doing so will require a heavy focus on diplomacy, reconstruction, and stabilization efforts—all of which to date the Trump administration has appeared reluctant to pursue. But in the absence of these efforts, any tactical success against ISIS or al Qaeda is likely to prove short lived. At the national level, easing Assad off the scene altogether within a reasonable time frame would be ideal. But in the highly likely event that this proves impractical, Assad’s powers should be significantly reduced and defused, allocated to the parliament and to the regional and local governing authorities. There are numerous models for decentralization, and the exact contours would have to emerge from negotiations between the regime and the opposition. But the key would be to devolve major governance responsibilities to the local level, including administration, policing, and essential service provision. “In essence,” as Dobbins, Gordon, and Martini observe, “this would scale up the model already at work in opposition-held areas, where local councils provide community-level governance with the support of external patrons.” Reducing the powers of the office of the Syrian president should also be accompanied by a phased process of reforming (or, if need be, dismantling) the internal security apparatus that keeps his regime in power, which is a core demand of the opposition movement. The success of a decentralized model will hinge on whether the external actors overseeing zones of influence outside Assad’s statelet promote local governance that is inclusive and not controlled by extremist or terrorist organizations. This will mean that significant attention and investment will need to be made in areas of northwestern, northern and eastern, and southwestern Syria that have largely been outside Assad’s control since 2012. Ideally, U.S. regional partners will manage these zones of influence to support moderate, elected, local-council-based governance. In northwestern Syria, where al Qaeda is setting down deep roots, this guiding role will fall mainly to Turkey and organizations from the Gulf Arab states, and the Trump administration should continue to apply pressure on these partners to promote moderate governance structures even as it continues discriminate, lethal targeting against al Qaeda.

The success of a decentralized model will hinge on whether the external actors overseeing zones of influence outside Assad’s statelet promote local governance that is inclusive and not controlled by extremist or terrorist organizations.

In southwestern Syria, the Trump administration should continue to work with Jordan, Gulf Arab partners, and, indirectly, Israel to support the Southern Front’s political platform, which could potentially serve as a model for other areas of Syria, including the northwest. The Southern Front’s political platform includes respect for sectarian and ethnic minority rights, the rejection of religious extremism, and protection of all Syrians’ rights to determine their country’s representative government. Also, included in the Southern Front’s covenant is a process whereby the armed opposition coalition’s constituent groups would slowly transition into local security forces, akin to a gendarmerie, as the conflict in their region winds down. In northern and eastern Syria, in the U.S. zone of influence, the SDF is supporting the Federal Democratic System of Northern Syria. This is meant to be a semi-autonomous region, composed of local municipal councils that are inclusive of the ethnic communities of the municipalities that made up the region. As the SDF and its partner force SAC seize more territory from ISIS in eastern Syria’s Euphrates River valley region, securing the political and security support of the local population, which is mainly Sunni Arab tribes, will be essential to preventing the re-emergence of ISIS. The U.S. military and civilian agencies should support the SDF and SAC to establish local councils composed of notables from the area and, over time, build up these local councils to support their own federal region. Conclusion As the war in Syria grinds on, the Trump administration may be tempted to focus solely on a narrow counterterrorism mission. That would be a mistake. The April chemical weapons attack was a reminder that the brutal war can have global consequences. And if the civil war rages, it will be impossible to deal a lasting defeat to extremist organizations like ISIS and al Qaeda. Time is of the essence. The Trump administration has an opportunity to seize the leverage that the United States has earned through its counter-ISIS campaign and recent cruise missile strikes to achieve a lasting solution to the civil war. It will not be easy. It will require an administration that has become increasingly comfortable with using military power and to engage in deft diplomacy to de-escalate the conflict, manage disputes, and reassure anxious allies. And it will require President Trump to do several things he has thus far been reluctant to do, including playing hardball with Moscow, engaging Iran, and supporting efforts to stabilize and rebuild Syria. In short, the “Art of the Syrian Deal” is possible. But it will take real leadership, a willingness to strike tough bargains with adversaries and allies alike, and the use of all instruments of American power to achieve a lasting peace.