Taking the Fight to “ISILstan”: Displacing and Replacing ISIL in Eastern Syria and Western Iraq


More so than at any time in recent history, last month demonstrated the dichotomous nature of the Islamic State in Iraq and the Levant’s (ISIL) current situation. On the one hand, the horrific attacks in Brussels demonstrated ISIL’s capacity to recruit and train operatives in European Muslim communities and build a local network capable of carrying out high-consequence attacks. On the other hand, ISIL also suffered major losses in its proto-state as the Syrian city of Palmyra fell to the Assad regime.

At the Center for a New American Security, we have been undertaking a review of U.S. strategy toward ISIL. We have previously written about an overall framework for addressing the problem and addressed the Syrian civil war stretching from Dara’a in the south to Aleppo in the northwest. Now it is time to turn to how the United States can displace ISIL from the territory it controls in its nascent caliphate in eastern Syria and western Iraq.

The Obama administration’s policy has focused heavily on this theater of the conflict, resulting in a reversal of ISIL’s battlefield momentum over the past year and a half. The overall approach is sound, though in many areas we believe more can be done to: (1) cultivate local actors who can provide security on the ground and displace ISIL; (2) increase direct U.S. military counter-ISIL efforts; and (3) leverage increased American investment on the ground to build leverage with key political players, especially the Iraqi government.

Perhaps most importantly, any strategy must also focus on building long-term governance and security structures in Syria and Iraq that prevent the emergence of the next ISIL. It was this failure that lead to the reemergence of ISIL in 2013 and 2014 after its predecessor, al-Qaeda in Iraq (AQI), had suffered major setbacks in 2007 and 2008. U.S. actions must keep this end state in mind. It is not enough to defeat ISIL. It must be replaced with resilient local institutions that can provide a bulwark against future Sunni extremism.

Western Iraq

In Iraq, the core challenge to a long-term alternative to ISIL is political and sectarian — not military. What the United States must avoid is a repeat of the failure to follow through on the Anbar Awakening, when the Sunni tribes rose up against AQI, but were then marginalized by the sectarian leadership of Iraqi Prime Minister Nuri al-Maliki. The immediate challenge is to build a credible local Sunni force that can work as an adjutant to the Iraqi Security Forces (ISF), to take and hold territory in western Iraq. But first, the ISF will need to become increasingly multi-sectarian, and the United States should continue to work toward this objective in capacity-building programs with the ISF. If Iraq’s counter-ISIL forces consist largely of Shia militias, the end result is likely to be increased sectarian violence. This will only further marginalize Iraq’s Sunni communities and divorce them from the Iraqi central government. In the long term, the development of capable local Sunni forces, essentially a Sunni equivalent to the Kurdish Peshmerga, can set the table for a power-sharing central governance structure that incorporates these Sunni forces and ensures that Sunni grievances are addressed.

Military efforts to roll back ISIL’s hold on territory should proceed on two tracks. The first is building internal armed opposition to ISIL inside of the territory it currently controls in western Iraq. Tribally mobilized resistance organizations such as Ninewah’s Quwat al-Usuud (Lions Force) are already providing the coalition with intelligence on ISIL and assist in providing targeting data for coalition airstrikes against ISIL targets. The United States should invest more heavily in recruiting these internal opposition actors that work against ISIL and providing them with weapons, training, and advising where possible. In some cases, that will mean taking greater risk to contact and potentially provide assistance to peel off ISIL’s uneasy Sunni allies that currently subordinate themselves to the ideological extremist organization because they strongly dislike Baghdad’s policies. While internal opposition organizations such as Quwat al-Usuud are not yet powerful enough by themselves to displace ISIL, they can be demonstrably more effective if coordinated into a resistance network that, alongside Iraqi national forces, can take and hold territory from the Islamic State.

The second track is building the capacity of the Iraqi Security Forces (ISF) to displace ISIL. The United States should make it a priority to work with Baghdad to empower the ISF’s most competent Sunni officers to take the lead in building out a multi-ethnic, multi-sectarian Sunni National Guard force that can hold territory taken from ISIL. This National Guard should be built as a Sunni force within the hashd sha’abi (PMU-Popular Mobilization Units) militia network with U.S. adviser oversight if possible, both to encourage greater inter-sectarian cooperation as well as to increase U.S. influence over the development of what has been one of the most sectarian armed forces in the counter-ISIL campaign. Reserve manpower for an expanded Sunni National Guard force could be mobilized partly from the hundreds of thousands of Sunni Iraqis that have been internally displaced from areas now under ISIL’s authority, most of whom are now resident in northern Iraq.

The Iraqi central government has been slow in arming and supporting Sunni opposition forces as a result of sectarian concerns and pressure from Iran, which carries significant influence in Baghdad. U.S. support for local Sunni tribal-based security forces should continue to be run through Baghdad with the assistance and coordination of the ISF. This would help to knit a closer relationship between the Iraqi national government and these bottom-up Sunni groups, an important political step. But the United States should make clear to the Iraqi government that if it is not willing to step up its support to the Sunnis, the United States is willing to provide direct support to local Sunni security forces. The reason for caution is the fragility of Hadar al Abadi’s government in Baghdad — one we would prefer to see remain in power and which could be harmed if the United States were to directly arm the Sunnis. But U.S. interests in rolling back ISIL are too important to be held hostage to dysfunctional Baghdad politics and at the end of the day Abadi’s ability to continue to keep his position has to do with the fact that there are not many viable alternatives and that none of the parties are necessarily interested in a months-long stasis that comes with the formation of a new government.

It is also important to not forget the Kurds, who have been the most effective fighting force in stemming ISIL’s momentum. But Iraqi Kurdish Peshmerga forces should not, and are not likely to agree to, serve as the displacement force that removes ISIL from Sunni Arab-majority areas of western Iraq. The United States should continue to work directly with the Kurdish Peshmerga and, if necessary, provide direct U.S. military assistance, including arms and salaries, to maintain Kurdish defenses against future ISIL attacks. This assistance is likely to be necessary because of the poor state of the economy of the Kurdistan Regional Government of Iraq (KRG). Suppressed oil prices and disputes with Baghdad over sharing diminishing oil revenues have made it increasingly difficult for the KRG to pay its security forces.

Beyond continuing to build and support local security forces, the United States should also be willing to take more risk by embedding advisors in Iraq at the battalion level. Right now, U.S. forces provide training and support to local forces on Iraqi government and Kurdish-held territory and provide air support when Iraqi forces go out to fight ISIL. They also conduct targeted special operations raids against high-value targets. But American advisors on the ground do not accompany Iraqi forces to the battlefield.

Embedding small numbers of Americans has been shown in the past to significantly increase the confidence and capacity of U.S. partners. Their presence also allows a closer integration between American airpower and partner ground forces. Finally, Iraqi security forces would be less likely to commit problematic acts, such as taking sectarian revenge in recaptured territory, under the direct watch of U.S. advisors. Such an approach also increases U.S. influence in Iraq relative to Iran, which provides precisely this type of support to Shia militias. Admittedly, this step would come with an increased risk of American casualties and also requires overcoming some political reticence from the Iraqis. But it should be pursued. Moreover, given the political dynamics in Iraq it is also difficult for the government of Iraq or some of these forces to accept visible American troop support, but the United States should continue to push on this door given how important it is to the overall effort.

In the long term, stability in Iraq requires a viable power sharing-agreement and inclusive governance and internal security structures. But this will only be possible if there are effective Sunni-led forces that can control western Iraq and be leveraged to build local governance structures, as the Kurds have done in the north. This will allow the Sunnis to negotiate from a stronger position as they try to come to political power-sharing agreements that address their grievances as part of a more integrated Iraqi government.

Eastern Syria

Similar to western Iraq, in eastern Syria the United States has also developed a strategy that has increased the pressure on ISIL and reversed battlefield momentum. This theater requires perhaps some additional steps, but not any fundamental shifts. Progress against ISIL in Syria has been piecemeal, a product of Syria’s messy, multi-sided civil war. Where possible, the United States is partnering with rebel groups that share U.S. interests in rolling back ISIL. A major difference in Syria is that, unlike Iraq, there is no legitimate central government to partner with in the campaign against ISIL. While Iraq’s Shia-dominated central government has often marginalized Sunni communities, reconciliation and power-sharing are not inconceivable in Iraq. In Syria, Bashar al-Assad’s regime is in open warfare not just against ISIL, but also against all rebel groups. Barring a major shift on one or both sides, pursuing reconciliation between Assad and rebel groups seems a quixotic undertaking.

In Syria, the patchwork counter-ISIL campaign is having greater success in the northern areas of the country than inside of ISIL’s core areas of control in eastern Syria. The United States is succeeding in northern Syria because it working through a coherent regional armed opposition coalition, the Syrian Democratic Forces (SDF). Militias within the SDF are highly motivated to remove ISIL from Syrian–Turkish border areas. The SDF is a multi-ethnic, multi-sectarian organization that represents the diversity of Syria’s Hasakah, Raqqa, and Aleppo governorates. Yet it remains dominated by Kurdish fighters and as such is not an appropriate force for displacing ISIL or holding territory in the majority-Arab areas under ISIL’s control.

A majority of the SDF units are composed of predominately ethnic Kurdish militias organized under the People’s Protection Units (YPG) umbrella. The YPG supports the development of an autonomous, multi-ethnic and multi-sectarian governing authority in northeastern Syria and has ties to the Kurdistan Workers’ Party (PKK). There are also credible reports that the YPG integrates PKK ideology throughout its organization, from the strategic to the local battalion level. Key U.S. partners, especially its NATO ally Turkey, strongly oppose the continued expansion of the SDF because of its ties to the PKK. Furthermore, a large number of non-SDF counter-ISIL Arab and Turkmen opposition groups believe that the SDF is a vehicle for militant Kurdish expansionism to displace Arabs and Turkmen from northern Syria.

For these reasons, it has been difficult for the United States to attract acceptable Arab-majority armed opposition groups to build out the SDF as a platform for defeating ISIL in eastern Syria. SDF expansion to seize the strategic Arab-majority areas of the Euphrates River valley, from ISIL’s putative capital of Raqqa to the Syrian–Iraqi border region near the city of Deir al-Zor, is particularly problematic. Still, the United States deserves credit for consistently applying pressure on the Kurds to seek out and incorporate an increasing number of Arab armed opposition groups into the SDF structure, most of which are composed of fighters that were displaced by ISIL from Raqqa and Deir al-Zor. In northern Syria, the SDF has great utility to the counter-ISIL campaign, and this line of effort should not be abandoned by the United States.

The United States should use its beachhead with the SDF to build out a forward operations base in the heart of the northeastern SDF-controlled Hasakah governorate, which would serve as the hub of coalition-led operations to displace ISIL in Raqqa and northern Deir al-Zor governorate. From this forward base, the United States can increase its training for opposition forces across Syria, bring in partner nations to help train a Sunni Arab hold force, and conduct direct action raids against ISIL further south in eastern Syria. This base can also provide secure lines of supply and reinforcement to support key Sunni Arab tribes that live under ISIL rule in eastern Syria, such as the Shammar, Ougaidat, Mashahda, Na’ime, Jabbour, Dulaim, and al-Shay’tat.

In addition to pushing from the north, the United States can also open a new front against ISIL in southern Syria. U.S. forces should continue to build out the capacity of the New Syrian Army (NSA), currently in the nascent stage of its development. The NSA is composed of eastern Syrian Free Syrian Army affiliates primarily displaced from Deir al-Zor governorate by ISIL. Most of the constituent militias within the NSA belong to the Saudi-supported Asala wal-Tanmiya umbrella organization, which is ideologically Islamist but amenable to a pluralistic post-conflict Syria. Though it also remains a developmental force, the NSA can stage from Jordan and take advantage of the sparsely populated, difficult-to-police southeastern Syrian Desert region.

In eastern Syria, the United States should also revisit the authorities it is providing to the U.S. military to allow for operations necessary to displace and replace ISIL. Even though eastern Syria and western Iraq is one unified battlefield controlled by ISIL, bureaucratic and historical reasons prevent the U.S. government from allowing the American military greater flexibility in eastern Syria. While the official border between Iraq and Syria has been virtually erased by ISIL, the military must obtain very high-level approval for nearly any action it takes on the ground in eastern Syria, despite its much greater flexibility in western Iraq. There should be an effort to ensure more consistent authorities and flexibility across both areas to allow greater freedom of action against ISIL.

Ultimately, this effort in pushing ISIL from the north and south will also have to be integrated with the approach we recommended in our previous article regarding a bottom-up approach for western Syria. The Syrian opposition forces the United States supports should also begin to press ISIL from the west. As we’ve seen in Palmyra, the Assad regime may also play a role in displacing ISIL from eastern Syria. However, most areas of eastern Syria strongly oppose the Assad regime and were early revolutionaries against it. It is doubtful that the regime can hold eastern Syria in its entirety or majority in the long term. The Assad regime’s continued presence there risks other ideological extremist organizations, particularly the al-Qaeda affiliate Jabhat al-Nusra and its close ally Ahrar al-Sham, reestablishing their presence in eastern Syria.

As ISIL is rolled back in Syria as it has been in Iraq, it will be critical for the United States to support the creation of sustainable, credible, and legitimate local governance structures to replace ISIL’s rule. This effort will be crucial to long-term success in the counter-ISIL campaign. The specific local governance structures will depend upon the political, ethnic, and sectarian mix of each part of Syria, and they will inevitably be a patchwork quilt of various opposition groups. Collectively, these local entities will have to be integrated into the federalized power-sharing arrangement that we have previously recommended for post-conflict Syria. This would consist of a weak central government with power devolved to local forces in southwestern Syria, northwestern Syria, currently regime-controlled and loyalist areas, the Rojava administration in the northeast, and the areas currently held by ISIL.


Achieving the overarching objective of displacing ISIL from eastern Syria and western Iraq and replacing it with an acceptable local governance structure that prevents the reemergence of the next ISIL will require a sustained long-term effort. It will require strong leadership from the United States to help identify and empower the right local actors. The United States will have to work with and at times apply pressure to sub-state actors and regional powers — partners and rivals alike — to work toward legitimate and sustainable governing structures in Syria and Iraq. To some degree in both countries, this will mean power-sharing arrangements that work through Damascus and Baghdad but grant significant local autonomy through a federal governing model. While local buy-in is necessary to a durable outcome, the United States cannot sit back and wait for various parties to reach a political agreement on their own. A more aggressive approach to destroy ISIL’s proto-state in Syria and Iraq is necessary. So long as ISIL controls its would-be “caliphate,” it will continue to have a strong argument to the transnational jihadist movement and to potential lone-wolf radicals that it is the rightful vanguard of global jihad.


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.