Syrian President Bashar al-Assad has not won his country’s civil war; rather, the war is entering a more dangerous phase. Forces fighting on his behalf have made important gains in recent years, capturing Syria’s second city, Aleppo, in 2016 and securing his capital, Damascus, in 2018. They are currently attacking the rebel stronghold in the southern provinces of Quneitra and Daraa, where the revolution began. Together, these victories have changed the trajectory of the war, weakening the moderate opposition and suggesting to many international observers that the fight for Syria is all but over.

But although the regime’s advances are impressive on a map, they will not end the war. Assad is weaker than he seems. His rule depends on the backing of foreign patrons, such as Iran and Russia, and the exhaustion of states that once opposed him, such as Jordan. His decision to internationalize the war will lay the foundation for future wars, and his tactics of mass slaughter threaten to fuel a long-term, global jihadist insurgency that will keep combat raging in Syria for years to come.

The United States must accept that ignoring Syria will lead not to a clean victory for Assad that establishes a stable peace but to more chaos down the road. To avoid that, the United States should invest now in building leverage for future decisive action by strengthening the military and governance capabilities of its partners on the ground, regaining the trust of Syria’s rebelling population, rebuilding rebel forces, and denying Assad the international legitimacy he so desperately craves. The United States still has options to constrain Assad and his backers—all it needs is the will to use them.

Old Quneitra viewed from the Golan Heights, July 2018. Ronan Zvulun / Reuters

Assad’s International War in Syria

Assad’s victories in the recent stages of the Syrian war have depended heavily on the support of Iran and Russia, which have combined to provide him with tens of thousands of ground troops, airpower, financial aid, and (in the case of Russia) diplomatic cover, without which his regime likely would have toppled. Although these interventions have stabilized the Assad regime in the short term, they are redrawing the power map of the Middle East in a way that will lead to further instability.

The first problem is that Iran and Russia will now be able to use Syria as a springboard for their international aggression. Russia has reportedly already begun to use its Syrian air base to support the operations of Kremlin-backed mercenaries in the Central African Republic and Sudan. Russian President Vladimir Putin’s ability to project force from Syria will aid his efforts to erode the NATO alliance and undermine the U.S.-led world order, allowing him to exploit the seams between the United States and its allies and partners. Iran, meanwhile, is establishing bases and creating Syrian proxies in order to open a second front against Israel in a future war. Israel will not tolerate this and could escalate to a ground operation in southern Syria to prevent it.

A further problem is that Assad’s depopulation of rebel communities is destabilizing neighboring states and driving regional instability in a way that will prolong the war. Jordan is possibly on the brink of collapse owing to the unsustainable number of Syrian refugees it has absorbed and has closed its border to 59,000 Syrians that fled Assad’s latest offensive in mid-2018. These populations may now be forced to live under a regime they sought to escape, creating a ripe environment for terrorists to exploit. Refugee flows are also incentivizing Turkish escalation. Ankara’s 2016 invasion of northern Syria was meant in part to check the Kurds but had the additional goal of relieving Turkey’s refugee burden by force. Turkey is now resettling refugees in northern Syria and building a rebel proxy force to govern them. But by sustaining anti-regime forces and populations, it is likely to prolong the war.

Ignoring Syria will lead not to a clean victory for Assad but to more chaos down the road.

Despite its support for rebel proxies, Turkey is pragmatically aligned in the short term with Assad and his backers to fight the Kurdish-led Syrian Democratic Forces (SDF)—the United States’ main partner in the fight against the Islamic State (ISIS)—because of its links to a Kurdish insurgency against the Turkish state. As the Syrian Kurds retaliate against Turkish forces and proxies in Syria and contemplate expanding their operations into Turkey, the Turkish-SDF war threatens to become a regional one. The United States has engaged Turkey to de-escalate this conflict but has taken no serious action to reform the SDF—for instance, by strengthening the Arab elements and constraining the Kurdish ones—in a way that might allow for a more conclusive deal. And after winning reelection last month, Turkish President Recep Tayyip Erdogan is more dependent than ever on political support from Turkish nationalists, which could drive him to further escalation.

A U.S. retreat from eastern Syria, where it currently has some 2,000 troops, would create a vacuum that various belligerents would compete to fill. Assad and his backers, Turkey, and jihadist groups such as al Qaeda and ISIS all hope to gain control of the areas that the U.S.-SDF alliance seized from ISIS. A U.S. withdrawal will only accelerate this conflict.

Global Jihad

In addition to the game of geopolitical chess now being played in eastern Syria, the region is a potential base for a resurgent al Qaeda and ISIS. Al Qaeda operated across eastern Syria before the rise of ISIS in 2014 and likely still has networks there. And ISIS, although weakened, is not defeated in Syria. It retains sleeper cells and forces in small pockets across the country, which continue to fight both Assad and the SDF. On June 22, ISIS claimed its first attack in its former capital, Raqqa, now held by the SDF, demonstrating its continued ability to inflict damage.

Assad’s gains on the battlefield will not end the jihadist insurgency, because it is Assad’s brutality that drives the insurgency. His tactics—chemical weapons, mass executions, starvation, torture—have broken the will of many rebel communities but hardened the resolve of tens of thousands of jihadists who will continue to fight him for decades to come.

In all likelihood, al Qaeda will lead that insurgency. It has the most capable forces among all the remaining Syrian rebel groups in western Syria. Its suicide bombers are decisive in overcoming Assad regime defenses that other Syrian rebels cannot penetrate. And while the group is building its Syrian fighting force, it is also recruiting foreign fighters in order to use Syria as a launch pad for future global attacks.

Currently, al Qaeda’s forces are concentrated in northwestern Syria and remaining rebel-held areas of southern Syria, but the group likely retains capable networks in regime-held areas. Periodic attacks against regime targets in the provinces of Aleppo, Hama, Homs, and Latakia throughout 2017 and early 2018 have demonstrated that al Qaeda and linked groups can penetrate areas ostensibly under Assad’s control. Similar attacks will likely occur in Damascus and southern Syria after Assad’s gains this year. (ISIS, too, has claimed attacks in regime-controlled areas.) Turkey, meanwhile, is allowing fighters with jihadist links into the areas it controls and ignoring the creation of an al Qaeda governance project in Idlib Province, on its borders in northwestern Syria.

A future in which Assad reimposes control and prevents jihadist threats to the West is a fantasy. He deliberately fueled the rise of both ISIS and al Qaeda in order to use them to hold the West hostage while he destroyed what threatened him most: the moderate rebels that wished to negotiate a peace. His conquest of the areas of southern Syria held by formerly U.S.-backed rebels would eliminate the last true bastion of moderate resistance to his rule, removing Western options and neutralizing the international diplomatic process by eliminating the rebels willing to negotiate. The defeat of moderates does not win Assad the war, however. It paves the way for groups such as al Qaeda to redefine the nature of the Syrian fight from a pro-democracy rebellion to a global jihad.

The Will to Act

How, then, should the United States respond? The most effective approach remains to build moderate groups that are willing to reunify the country via a negotiated settlement. Assad’s military gains have not won him back the support of rebelling populations. The most significant obstacle to building a partnered rebel force remains the absence of U.S. will and commitment. Previous U.S. efforts to build rebel partners were doomed to fail because Washington attempted to prevent them from fighting Assad. A concerted U.S. effort to rebuild the fighting ability of moderate rebels without such constraints could fundamentally change the course of the war. SDF fighters near Deir ez-Zor, May 2018. Rodi Said / Reuters

The United States should salvage forces from moderate groups in southern Syria, such as the First Army, that wish to continue fighting Assad. Under considerable military pressure, these groups have begun to surrender to the regime. Some will likely be relocated to Turkish-held areas of northern Syria, but those that stay may turn to supporting a future jihadist insurgency as their only way to resist. The United States should offer these rebels another option.

The south will likely fall to forces allied with the regime unless the United States acts immediately, but even if it does, Washington still has options. It can leverage the SDF against Assad and his backers and rebuild rebel capability over time.

The SDF controls large portions of Syria’s oil resources, which the United States should continue to deny to the regime. But the SDF is a problematic partner. Its Kurdish leaders are implementing a repressive form of governance to eliminate political competition in the areas it controls, and the group lacks the necessary resources and bureaucratic capabilities to govern the Syrian populations under its rule. If it is allowed to continue, the mismanagement of SDF-held areas threatens to fuel a resurgence of ISIS and the rise of an anti-SDF insurgency that could be exploited by al Qaeda. Washington should commit additional resources toward transforming the SDF into an effective governing structure and military force. The United States should condition its support of the SDF on good governance and take steps to hold the group accountable by, for instance, bringing human rights monitors into SDF-held areas to inspect internally displaced persons camps and prisons and by enabling locals to file complaints directly with the United States.

The United States will also need to regain credibility with the Syrian population. Reforming the SDF and investing in the stabilization and recovery of areas under SDF control would help. So would helping refugees and internally displaced persons to return to areas under U.S. and SDF control. These steps can enable the United States to recruit rebel fighters from the returning populations, which will remain opposed to Assad’s continued rule.

Finally, Washington should recognize the failure of the international diplomatic process and walk away. Doing so would block a renewed effort by Russia to hijack the diplomatic process by spurning the UN-backed talks while hosting its own efforts in Sochi, thus building goodwill with Syria’s rebelling population. Washington will also need to reach a deal with Turkey that ends its war with the SDF and aligns Ankara with the United States against the Assad regime and its backers. The deal would likely entail concessions that allow acceptable Turkish-backed forces and proxies to help secure Arab-majority areas in eastern Syria currently under SDF control.

The steps outlined here would neither solve the Syrian war nor force Assad to negotiate. They would, however, provide the United States with leverage and begin a U.S. pivot toward engagement in Syria after the nominal defeat of ISIS. These steps are costly and difficult, but they reflect the best way forward in a vicious war that, far from drawing to a close, will morph into new—and potentially more deadly—conflicts.