A Strategic Framework for the Fight Against ISIL


Recent attacks in San Bernardino, Paris, and Sinai are a reminder that the Islamic State in Iraq and the Levant (ISIL) is not just a regional phenomenon, but a threat with global reach that requires a clear and forceful U.S. response. At the Center for a New American Security (CNAS), we have begun an effort to review current U.S. strategy and propose a way forward. Given the complexity of the situation in Syria and Iraq — and increasingly outside of the Levant in Libya, the Sinai, Yemen, Afghanistan, and Nigeria — the first challenge that we undertook as part of the CNAS study group was to develop a coherent strategic framework through which to view the problem. Defeating ISIL will require an approach that addresses three separate but interrelated theaters:

1. The Syrian civil war from Aleppo to Dara’a: While ISIL is not the main protagonist in this conflict, it has drawn strength from the vacuum created by the war between the Assad regime and its armed opposition opponents in western Syria. Furthermore, ISIL and other radical Sunni jihadist groups (e.g., Jabhat al-Nusra, Jund al-Aqsa, Ahrar al-Sham, Harakat al-Muthanna al-Islamiyya, Jabhat Ansar al-Din, and Liwa Shuhada al-Yarmouk) are empowered by the broader Sunni–Shi’ite civil war within Islam that is playing itself out on the battlefields of Syria, Iraq, and Yemen. ISIL can be degraded but not entirely eliminated until this war ends.

2. ISIL-controlled eastern Syria and western Iraq: Today ISIL controls a vast swath of territory in eastern Syria and western Iraq that it deems the Caliphate. Unlike other jihadist groups, ISIL has linked its legitimacy with the state-building enterprise. Thus, the ongoing U.S.-led campaign has focused on rolling back these territorial gains. Despite slow-sustained progress, particularly by our Kurdish partners, it is hard to see how to win this fight without a credible Sunni Arab alternative that can take and hold ISIL territory. Kurdish fighters and Iraqi government forces will be able to make gains around the edges, but pushing out ISIL will require empowering more moderate Sunni elements on both sides of the Syria–Iraq border.

3. ISIL’s global brand appeal: ISIL has quickly eclipsed al-Qaeda in international brand recognition for jihadist terrorism. ISIL’s decentralized approach of inspiring smaller-scale or even lone wolf attackers is harder to thwart than al-Qaeda’s preference for spectacular attacks. And its ability to take and hold territory in a way al-Qaeda never could has reinforced its messaging across the globe. ISIL is taking the shape of a diffuse global movement rather than a network. Defeating ISIL requires a sustained, multinational effort to track and contain foreign fighters and counter the group’s message.

This article, the first in a series that we plan to write in the coming months, examines the challenges and key strategic questions associated with each of these theaters. Future articles will dive deeper into each of these components and suggest a strategy for a way forward.

The Syrian Civil War

The civil war in western Syria is a complex conflict that has no purely military solution. The remnant of the Syrian Arab Republic governed by the Assad regime will likely sustain itself in the form of a statelet whose security will be buttressed by the intervention of foreign actors, most prominently Russia, Iran through its Islamic Revolutionary Guard Corps (IRGC), Lebanese Hezbollah, and IRGC-supported militias mobilized from Iraqis and Iranian Afghan refugees. On the armed opposition side, over the course of the civil war perhaps as many as a thousand armed groups have been mobilized, without unity of leadership, or a clear desired end state for post-conflict Syria. Many of these groups are militant Sunni Islamist in their ideology, particularly Ahrar al-Sham, and have accommodated themselves to the rising power of the al-Qaeda affiliate Jabhat al-Nusra — and frequently and closely cooperate with it in military operations, including in formal alliance in the Jaysh al-Fateh (Army of Conquest) coalition and in the administration of rebel held areas of northern Syria.

Further complicating the situation in western Syria is the role of external actors, including Iran and Lebanese Hezbollah, Russia, Turkey, Qatar, Saudi Arabia, other Gulf states, Europe, and the United States. These actors have different and conflicting priorities and their intervention and competition is kerosene on an already raging fire. The competition between these external actors has enhanced extremist participants in the conflict on all sides. The Syrian civil war is more than an internal conflict. It is a proxy war for regional and global influence among a variety of actors. In an attempt to gain influence on the ground in Syria, Qatar, Saudi Arabia, and Kuwait (and Turkey) have provided weapons and money to ideologically extremist actors and the rebel coalitions, such as Jaysh al-Fateh.

It is highly unlikely that an external power is going to take over Syria, and increasingly it looks as if no side in the conflict is going to win decisively. Thus, the central challenge is how to get to a lasting political solution that will, over time, allow for a post-conflict security architecture that is acceptable to the primary combatants and outside powers. The key point of contention among policymakers is whether conditions are ripe for a ceasefire and de-escalation of the war, or if the United States and its partners must shift the military balance on the ground to reshape the calculus of key actors before an agreement is possible.

As it stands now, the Obama administration is subscribing to the first approach, preferring to seek a series of local, and then national, ceasefires that lead to an eventual de-escalation of the conflict through the Vienna process. The administration believes that the Russians are nervous about being drawn further into the quagmire of the Syrian civil war. They furthermore believe that the Iranians and their proxy forces have suffered heavy casualties. According to this logic, the Russians and Iranians are on the path towards accepting a peace process that leads to the eventual removal of the Assad regime. The White House is averse to escalation through a significant increased support for the Syrian armed opposition, establishing a limited no-fly or safe zone, or choosing to strike directly at selected Assad regime targets. It believes that increased American involvement will cause others to escalate in response.

An alternative reading is that Russia and the IRGC are quite confident that they have leverage in Syria and have secured Assad’s statelet, causing them to raise their demands at the negotiating table. Meanwhile, the Gulf Arabs are insecure and nervous about regional events, fearing an American withdrawal and pivot to Tehran. This is leading to more aggressive behavior from the Arab states and unrealistic demands in a diplomatic process to end the war. The United States has little leverage on the ground and only weak relationships with key opposition actors. If this reading is correct, a diplomatic process to resolve the civil war in western Syria will likely fail. Negotiating a peaceful resolution will require reducing the demands of the Assad regime and its allies, reassuring regional partners, and increasing leverage on the ground. To accomplish all of these things, the United States would need to first shift the military balance of power on the ground.

The jury is out on which of these perspectives is the correct one. The diplomatic process that has been launched by Secretary Kerry in Vienna may provide some greater clarity on this question in the weeks and months ahead. But while we certainly support diplomatic efforts to end the conflict, we remain skeptical that the balance on the ground is currently conducive to an agreement.

Retaking ISIL Territory

The second component of the strategic framework is the effort to displace ISIL from the territory that it controls in western Iraq and eastern Syria. These areas are inhabited by a predominately Sunni Arab population, which often organizes via tribal structures. In both western Iraq and eastern Syria the greatest challenge that confronts the United States and its allies is how to build credible Sunni forces that can retake territory from ISIL and hold liberated territory.

This will be especially challenging in Iraq where the Sunni community has been marginalized by the Shi’a-led government in Baghdad. The majority of the fighting against ISIL in Iraq is being conducted by sectarian Shi’a militias and Kurdish Peshmerga forces that want to establish their dominance over highly contested areas such as Kirkuk. These moves worry the Iraqi Sunni community. Many of ISIL’s Iraqi Sunni supporters view themselves as a marginalized population that is under siege. Advances into traditionally Sunni territory by non-Sunni Arab ground forces only further aggravate this powerful sense of disenfranchisement. Kurdish and Shi’a forces may seize territory, but risk driving more Iraqi Sunnis into the arms of ISIL. Absent a comprehensive political settlement between Iraq’s Sunnis, Shi’a, and Kurds (which doesn’t appear to be on the horizon anytime soon), rolling back ISIL will require empowering more moderate Iraqi Sunnis.

Shifting the balance of power among Sunni communities in ISIL-held territory in western Iraq and eastern Syria is perhaps even more important than de-escalating the broader sectarian, regional, and global conflicts that help to fuel ISIL. In western Iraq, ISIL has emerged as the “strongest tribe” and leading socio-political and military actor within a larger Iraqi Sunni armed opposition coalition. ISIL is the kingmaker, leader, and coordinator of the efforts of a number of local Iraqi Sunni armed opposition actors, ranging from Ba’athist Iraqi nationalist groups to more ideologically extremist organizations such as the Army of the Men of the Naqshabandi Order and Ansar al-Islam.

While subservient to ISIL’s objectives at present, there are indications that some of these organizations may be willing to reach an accommodation with Baghdad against ISIL, which is threatening their position within Iraqi Sunni society. But getting these parties to reverse their allegiances will require overcoming their shared dislike for the current Baghdad government, and their distrust of the United States. A key question for U.S. policymakers is whether they should continue to run the anti-ISIL campaign in Iraq exclusively via Baghdad and Erbil, or if it is time to directly arm Sunni groups willing to stand up and fight against ISIL inside of western Iraq. Another challenge is how to apply pressure in Baghdad, and to a lesser extent Erbil and Sulaymaniya, to begin a process of political reconciliation among Iraq’s Sunni, Shi’a, and Kurdish communities.

In eastern Syria, the United States is building out a workable model for seizing and disrupting strategically important lines of communication along the Syrian–Turkish and Syrian–Iraqi borders. It is also working to empower armed opposition forces to take the fight to ISIL. The Syrian Democratic Forces (SDF) coalition — which is primarily led by Kurdish militia forces but also includes Sunni Arab armed groups as well as militias from other ethnic and sectarian minorities — has been critical in this fight. While not yet capable of moving on ISIL’s putative capital of Raqqa, the SDF is having real battlefield successes. In an important move for the future of Syria, the SDF also working towards greater inter-ethnic cooperation in civil and military governance that can be a model for post-conflict Syria. This model is still shaky, but strengthening.

Simultaneously, a new Sunni Arab armed opposition organization, called the New Syrian Army, which is composed of more ideologically moderate Islamist rebel groups that were displaced by ISIL from Deir al-Zor, is being provided U.S. support to open a second front against ISIL deep in territory that it controls. The New Syrian Army is following a strategy to build lines of influence into core ISIL areas in Deir al-Zor, foment tribal uprisings against ISIL, and provide support to the communities that have risen in revolt.

The real challenge for U.S. strategy in eastern Syrian will be mobilizing, coordinating, and supporting local partner forces, especially Sunni Arabs, to march on and seize Raqqa and Deir al-Zor and then to hold territory once liberated. These day-after-ISIL scenarios will require an inclusive and resilient Sunni Arab armed opposition civil-military structure. At present it is unclear if the SDF has the lines of influence into Raqqa and the areas around Deir al-Zor to accomplish this objective.

The United States will need to work with the Kurds to continue to build out a strong Sunni Arab and Turkmen component to the SDF, even as many Sunni Arab communities are suspicious of the Kurds’ ultimate territorial ambitions inside of Syria. Another challenge is how to get the Gulf Arab states, particularly Saudi Arabia and the United Arab Emirates, to be active players on the ground and to financially support post-ISIL governance and security in eastern Syria, possibly including the organization of a peacekeeping force in eastern Syria.

As a tactical matter, the United States will have to decide how much military force it commits to training, advising, and assisting partner forces in Syria and Iraq. While U.S. forces should not be in the lead for combat operations, there are a range of options for how closely U.S. special operations advisors should be integrated with partner forces, anywhere from assisting in headquarters planning to accompanying them in frontline combat operations. U.S. advisors can be powerful enablers for local forces, but they are no panacea. Embedding U.S. forward air controllers alongside local forces to call in air strikes, for example, may assist in delivering more tightly integrated airpower to support ground forces, but cannot compensate for ground forces that are incompetent, lack the will to fight, or are not supported by the local population.

The Global Campaign

A critical third component in defeating ISIL is countering its efforts to recruit, mobilize, and transfer foreign fighters abroad. A central part of this challenge is how to counter ISIL’s messaging that it uses to attract supporters. The United States has been a leader in pursuing effective strategies to overcome these challenges in the context of the global anti-ISIL coalition, with some considerable success. But the driving factors of these challenges will require much greater leadership effort from the United States. Foremost among these drivers are the economic, social, and political marginalization of Sunni Muslim populations throughout the Middle East and North Africa, and now increasingly in Europe, Africa, and Southeast Asia. ISIL’s appeal is further reinforced by its establishment of its caliphate in Iraq and Syria and its claim to be the epoch-making irresistible corrective movement within Islam.

Middle Eastern states are unable to meet the growing demand for greater economic opportunities, credible political participation, and socio-cultural rights. Many of these countries are either major U.S. partners or states in which the United States provides significant security and civil society assistance. Each of these countries has different strategies for marginalizing, or directly and aggressively confronting, the networks that support ISIL. However, addressing the socio-political and economic factors that drive some of their citizens to look to ISIL for leadership requires sustained, progressive, and hard reforms that may reshape the internal stability of key U.S. regional partners.

Deserving special attention is Libya, which in the aftermath of a U.S.-led air campaign to oust former dictator Muammar Gadhafi, is in the middle of its own civil war. Amidst this power vacuum, Libya is a site of territorial control and strategic depth for ISIL in the trans-Sahara region. The emergence of Libya as an important theater against ISIL, although not yet on par with Syria and Iraq, is an increasingly important one for European security. ISIL uses Libya as a staging point to plant jihadists among the hundreds of thousands of migrants from the Middle East, North and East Africa, and sub-Saharan Africa, many of whom are funneled into Libya via ISIL-controlled smuggling routes in the trans-Sahara region.


Ultimately, defeating ISIL is a complex and daunting task. The United States will need to consistently create linkages among the three components within this strategic framework: concluding the Syrian civil war, retaking and holding ISIL territory, and diminishing ISIL’s global brand appeal. U.S. policymakers will need to view the anti-ISIL campaign as a global war, involving diplomatic, economic, and informational tools as well as military action. Each of the three core components of this strategic framework will be explored in greater depth in the subsequent pieces in this series, with the goal of crafting a viable U.S. strategy for defeating ISIL.


Ilan Goldenberg is the Director of the Middle East Security Program at the Center for a New American Security where Nicholas A. Heras is the program’s Research Associate. Paul Scharre is a Senior Fellow at CNAS and a former Army Ranger with service in Iraq and Afghanistan.