June 16, 2016

Defeating the Islamic State

A Bottom-Up Approach

Fifteen years after September 11, 2001, al Qaeda has taken significant losses, but the threat from Islamic extremism has morphed and metastasized in ways that remain dangerous to U.S. interests. The most recent iteration of this threat is the rise of the Islamic State of Iraq and al-Sham (ISIS), and the emergence of its proto-state in the heart of the Middle East. The ambitions of the Islamic State pose a direct threat to the United States and its allies. Not only has ISIS created chaos and violence in Iraq, Syria, Libya, and other weak, unstable states, but it has also executed major attacks in Europe and the downing of a Russian airliner in Egypt, and inspired an attack in California. Given the scale of the threat, the United States and its partners must act now to intensify the fight against ISIS in multiple ways.

To address this challenge, for the past six months CNAS has convened regular meetings of its ISIS Study Group, composed of former military officers, former government officials, and experts on counterterrorism and the Middle East. Below we offer an overall strategy and series of recommendations both for President Obama and to his successor who will inherit this problem. These recommendations are informed by the deliberations of the CNAS ISIS study group, and reflect the ideas that emerged from those discussions. But the report represents the views of the three authors alone.

The Current Approach And Its Limitations

In September 2014, President Obama announced a plan to “degrade and ultimately destroy ISIS.” The administration’s approach, which to date has made gains in rolling back 40 percent of ISIS-held territory, has been based on arming and advising local forces and providing them with air support to retake territory, even as the United States continues to directly target ISIS leadership with Special Operations Forces and air power.

The approach has not been as successful as it must be. It relies too heavily on ground forces that are predominantly Kurdish and Shia, and has not yet built sufficient Sunni forces to retake and, more importantly, hold ISIS territory. U.S. military support has also been limited in a number of unnecessary ways. A lack of embedded combat advisors supporting partners on the front lines, hesitation to deploy more troops, and inadequate delegation of authority have all slowed progress.

The much bigger flaw in the strategy is the policy toward the civil war in western Syria. The Obama administration has prioritized the ISIS fight in the east while seeking a political solution for the civil war in the west. But it was the Syrian Civil War that accelerated ISIS’ emergence from the ashes of al Qaeda in Iraq in the first place. If the proto-state in eastern Syria and western Iraq is eliminated and extremist safe havens remain in western Syria, ISIS or like-minded groups will take advantage of the situation to hold territory and continue to present a threat. Moreover, many of the key external regional actors prioritize the outcome of the Syrian Civil War over the defeat of ISIS, and if Washington wants to get their cooperation in fighting ISIS — a necessary prerequisite for its defeat — the United States will need to put a higher priority on resolving the war. Finally, prioritizing a political agreement today in Syria, with little American leverage on the ground and conditions that are far from ripe for an agreement, is unlikely to end the conflict.

An Alternative Approach

The overall objective of American strategy should be to significantly reduce and, over the long term, eliminate the ability of ISIS to execute and inspire attacks against the United States and its partners. This will require the United States and its partners to destroy the proto-state in Iraq and Syria, which is ISIS’ center of gravity. As long as ISIS retains its safe haven it has a base from which to plan attacks against the United States and its allies, and will also be able to present itself as the vanguard of the global Sunni jihadist movement. Equally important and much more difficult to accomplish will be preventing the proto-state’s reemergence or the emergence of alternative extremist groups that can hold territory in Iraq and Syria.

In ISIS-controlled territory, this strategy does not entail a fundamental shift in current U.S. strategy but instead some course corrections. Most importantly, it means a willingness to lean further forward in the types of military action the United States would take in this territory. It emphasizes above all the importance of training local security forces to retake ISIS-held territory and entails a longer slow-burn strategy that may take a number of years but focuses on building the right hold force as opposed to retaking territory with forces that will ultimately be unacceptable to the local population. Importantly, the United States would not introduce U.S. conventional ground troops with the intent of directly engaging in U.S.-led ground combat operations to seize territory from ISIS, as such an approach would be unlikely to work without an adequate force to hold that territory in the aftermath.

The overall objective of American strategy should be to significantly reduce and, over the long term, eliminate the ability of ISIS to execute and inspire attacks against the United States and its partners.

In western Syria, a more radical shift is needed. Rather than focusing first on coming to a political agreement, the United States should emphasize arming and training local groups that are acceptable to the United States regardless of whether they are fighting Syrian President Bashar al-Assad or ISIS. The purpose of this effort is not just to defeat ISIS but to have these groups marginalize other extremist actors and to leave in place an acceptable sustainable long-term governance and security situation, which eliminates future terrorist safe havens and marginalizes al Qaeda’s influence and presence. The United States should also be willing to increase its use of military coercion in the west and be willing to threaten and execute limited military strikes against the Assad regime in order to protect these actors while signaling to all of the key external actors in Syria, including both its Middle Eastern partners as well as Russia and Iran, that it is willing to get more engaged.

Over time, these dual approaches to displace ISIS in the east and ensure greater moderate control in the west can roll back extremist influence across Syria and Iraq and set the conditions for negotiated political outcomes in both countries. In Iraq, as a local Sunni force extends its influence and control and displaces ISIS, it can increase Sunni leverage in negotiations with Baghdad and over time help facilitate power-sharing arrangements in Iraq that reflect the new security situation on the ground. In Syria, as moderate forces increase their influence and control in the northwest and southwest, eventually there can be a power-sharing agreement — acceptable to Turkey, Saudi Arabia, Russia, Iran, and the internal actors — in which the successor to the Alawi-led Assad regime remains in control of its territory, but local groups reflective of Syria’s ethnic and sectarian mix control and govern their territory.

Policy Recommendations

The approach described above requires four interlocking efforts:

Build coherent regional armed opposition groups from the bottom up that can hold territory, provide security, and marginalize extremists. To achieve this, the United States should:

1. Increase U.S. support for the Southern Front in southwest Syria.

  • Focus U.S. support efforts on Jaysh al-Nasr and the Al-Farqa al-Shamaliyya coalition in northwestern Syria, and use them to pursue a patient long-term approach for peeling away organizations from Jabhat al-Nusra and its close allies in the opposition.
  • Use northeastern Syria as a beachhead from which the United States can train Sunni Arabs displaced from ISIS-controlled eastern Syria and reach into local tribes, while continuing to expand support for the New Syrian Army in southeast Syria.
  • Prioritize training of Sunni forces in Iraq, ideally through the Iraqi central government, but if that continues to fail, then directly.

2. Increase direct U.S. military support to opposition groups and U.S. direct action counter-network operations against ISIS. Specifically, the United States should:

  • Embed combat advisors at the battalion level in Iraq and, over time, eastern Syria to enable partner forces to fight ISIS more effectively.
  • Expand direct action counter-network military operations to degrade ISIS’ ability to carry out external attacks.
  • Establish more flexible authorities for military assistance and intervention, especially in eastern Syria.
  • Eliminate artificial manpower limitations so that the military missions can be properly resourced.
  • Use military coercion to deter airstrikes in southwest and northwest Syria to allow local acceptable opposition forces to govern and provide security, including using deterrence and punishment to establish a “no-bombing zone” in certain opposition held territories.

3. Leverage increased U.S. investment on the ground into diplomatic influence with key external actors. To achieve this, the United States should:

  • Connect U.S. military actions to a messaging strategy of decisive U.S. intervention against ISIS and a more forceful approach against Assad in order to maximize the diplomatic impact of U.S. actions.
  • Leverage greater U.S. commitment to addressing the conflict and more willingness to push back on Iran’s destabilizing activities to get Gulf Cooperation Council partners to coordinate their support to armed opposition groups.
  • Obtain greater Turkish cooperation in arming non-extremist opposition groups and strengthening border control efforts, in exchange for increased U.S. effort in western Syria, putting limits on support for militant Kurdish expansionism and a greater willingness to use military threats and coercion to deter airstrikes near the Turkish border. Also continue to obtain Turkish acquiescence for a combined Kurdish-Arab offensive in the Manbij Pocket.
  • Achieve an agreement with Russia, over the long term, on a Syrian power-sharing agreement that maintains a strong loyalist center and more moderate forces holding territory in non-loyalist areas.
  • Convince Iran, over the long term, to accept a power-sharing agreement in Syria with a strong loyalist center, and an outcome in Iraq where the Shia central government retains control but meaningfully addresses Sunni grievances.

4. Reestablish legitimate and acceptable governance and negotiate a political end-state for the conflicts in Iraq and Syria. To achieve this, the United States should:

  • Emphasize the importance of inclusive and responsible governance and incentivize U.S.-supported groups to adhere to political platforms consistent with those values, using the 2015 Riyadh Declaration as a key building block.
  • Support and fund local municipal councils as the essential governance building block that complements U.S. strategy to arm local actors, and over time leverage these local councils to build out regional governance. Ensure this aid is closely coordinated with lethal aid and enabling these local councils to govern more effectively than extremist groups.
  • Remain heavily engaged in Iraqi politics and continue to try to bring the various sectarian parties together; over the long term, leverage the creation of a Sunni hold force to increase the possibility of a power-sharing outcome between Baghdad and the Sunni minority.
  • Over the long term, after reshaping the situation on the ground, facilitate a negotiated agreement that ends the Syrian civil war and leaves in place a unitary but highly decentralized Syrian state.
  • Pursue a political end-state that maintains the territorial integrity of Iraq and Syria as the preferable outcome, but be willing to accept a wide variety of decentralized governance structures that lead to a near breakup of these states, if that is the most realistic option to best meet core U.S. objectives of defeating ISIS and replacing it with a sustainable alternative.


This approach comes with some real risks. Increased military involvement places more U.S. troops in harm’s way, but the authors believe the risk is merited given the nature of the threat to American citizens and interests at home and abroad. Expanding support to opposition groups risks more weapons falling into the wrong hands in Syria, but at this point we believe the risk of not trying to enable more acceptable actors in Syria is higher than trying. Establishing a no-bombing zone would risk escalation with Russia, but this concern is manageable given that neither side wants to enter a direct conflict and the United States needs to exert some military pressure if it wishes to change Russian and regional calculus and empower more acceptable actors on the ground. While it may be impossible to ever forge a political agreement inside Syria and Iraq, even in that case the approach recommended would enable more responsible actors to seize and hold territory and eventually more ably manage the breakup of these states while reducing the establishment of extremist safe havens.

Perhaps the greatest risk is that this is a strategy that will take years to execute. During that time the dangers posed by ISIS will remain.

Perhaps the greatest risk is that this is a strategy that will take years to execute. During that time the dangers posed by ISIS will remain. Therefore, in addition to focusing on the ISIS proto-state in Iraq and Syria, the United States will also have to continue to vigilantly take steps to prevent new proto-states from forming in other parts of the world such as Libya, the Sinai, or Afghanistan. We will also have to work with our partners to counter ISIS’ transnational foreign-fighter network through more effective localized counter-radicalization programs to prevent recruitment and foster better intelligence gathering and sharing to stop those who have been radicalized.

The threat posed by ISIS is deeply complex. Certainly, a number of the policies recommended may fail to achieve their desired objectives or have unexpected secondary effects. Still, the authors believe that the approach outlined in this report argues for an overall investment in American blood and treasure that is proportionate to U.S. interests and recommends a strategy that takes acceptable risk to destroy the ISIS caliphate and achieve important U.S. objectives.

Members of the CNAS ISIS Study Group

For the past six months CNAS has convened regular meetings of its ISIS Study Group. The recommendations outlined in this report are informed by the deliberations of that group, and reflect the ideas that emerged from those discussions. The report represents the views of the three authors alone.


Hon. Michèle Flournoy

Richard Fontaine


Ilan Goldenberg


Hon. Rand Beers

Dr. Erica D. Borghard

Shawn Brimley

Hon. Derek H. Chollet
Dr. Steven A. Cook

Amb. Ryan C. Crocker

Melissa Dalton

Hon. James N. Miller

William C. Danvers

Brian Fishman

Michael Gordon

Nicholas A. Heras

Hon. Kathleen H. Hicks

Dr. Kimberly E. Kagan

Brian Katulis
Valery C. Keaveny, Jr. (USA)
Dr. Joshua M. Landis
Sen. Joseph I. Lieberman

Dr. Marc Lynch

Lt Col Robert Lyons (USAF)

LtCol Peter McAleer (USMC)

Dr. William McCants

Dr. Carole A. O’Leary

Dr. Meghan L. O’Sullivan

GEN David H. Petraeus, USA (Ret.)

Dr. Kenneth M. Pollack

Paul Scharre

Loren DeJonge Schulman
Julianne Smith

Andrew Tabler

Dr. Stephen Tankel

Frances F. Townsend

The full report is available online.

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  1. See Kimberly Dozier, “U.S. Special Ops Kill 40 ISIS Operatives Responsible for Attacks From Paris to Egypt,” The Daily Beast, April 28, 2014, http://www.thedailybeast.com/articles/2016/04/28/u-s-kills-isis-operatives-linked-to-europe-attacks.html?utm_source=Sailthru&utm_medium=email&utm_campaign=New%20Campaign&utm_term=%2ASituation%20Report; Bryan Schatz, “The Pentagon Says It Has Killed 20,000 ISIS Fighters — and Just 6 Civilians,” Mother Jones, http://www.motherjones.com/politics/2015/12/united-states-isis-bombing-civilian-deaths; Gordon Lubold and Adam Entous, “U.S. to Send 250 Additional Military Personnel to Syria,” The Wall Street Journal, April 24, 2016, http://www.wsj.com/articles/u-s-to-send-250-additional-military-personnel-to-syria-1461531600?utm_source=Sailthru&utm_medium=email&utm_campaign=New%20Campaign&utm_term=%2ASituation%20Report.
  2. William McCants, The ISIS Apocalypse: The History, Strategy and Doomsday Vision of the Islamic State (New York, St. Martin’s Press, 2015), 29, 145.
  3. Ibid., 158; Michael W.S. Ryan, Decoding Al-Qaeda’s Strategy: The Deep Battle Against America (New York, Columbia University Press, 2013), 134, 256–67.


  • Ilan Goldenberg

    Former Senior Fellow and Director, Middle East Security Program

    Ilan Goldenberg is the former Senior Fellow and Director of the Middle East Security Program at the Center for a New American Security. He is a foreign policy and defense expe...

  • Nicholas Heras

    Former Fellow, Middle East Security Program

    Nicholas A. Heras is a former Fellow at the Center for a New American Security (CNAS), working in the Middle East Security Program. His work focused on the analysis of complex...

  • Paul Scharre

    Executive Vice President and Director of Studies

    Paul Scharre is the Executive Vice President and Director of Studies at CNAS. He is the award-winning author of Four Battlegrounds: Power in the Age of Artificial Intelligence...

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