Developing a Containment Strategy in Syria
Some U.S. policymakers have argued that the United States should withdraw its military forces from Syria. But the United States has several interests in Syria:
- Balancing against Iran, including deterring Iranian forces and militias from pushing close to the Israeli border, disrupting Iranian lines of communication through Syria, preventing substantial military escalation between Israel and Iran, and weakening Shia proxy forces.
- Balancing against Russia, including deterring further Russian expansion in the Middle East from Syrian territory and raising the costs—including political costs—of Russian operations in Syria.
- Preventing a terrorist resurgence, including targeting Salafi-jihadist groups like the Islamic State and al Qaeda that threaten the United States and its allies.
Based on U.S. interests in Syria, Washington should establish a containment strategy that includes the following components:
- Retain a small military and intelligence footprint that includes working with—and providing limited training, funding, and equipment to—groups in eastern, northern, and southern Syria, such as the Syrian Democratic Forces (SDF).
- Coordinate with regional allies such as Jordan and Israel to balance against Iran and Russia and to prevent the resurgence of Salafi-jihadists.
- Pressure outside states to end support to Salafi-jihadists, including Turkey and several Gulf states.
As the war in Syria moves into its seventh year, U.S. policymakers have struggled to agree on a clear Syria strategy. Some U.S. policymakers have argued that the United States needs to withdraw its military forces from Syria. “I want to get out,” President Trump said of the United States’ military engagement in Syria. “I want to bring our troops back home.”1 Others have urged caution, warning that a precipitous withdrawal could contribute to a resurgence of terrorism or allow U.S. competitors like Iran and Russia—along with their proxies—to fill the vacuum.2 In addition, some administration officials have argued that the Islamic State has been decimated in Syria and Iraq. The National Security Strategy notes that “we crushed Islamic State of Iraq and Syria (ISIS) terrorists on the battlefields of Syria and Iraq.”3 But between 5,000 and 12,000 Islamic State fighters remain in Syria and continue to conduct guerrilla attacks, along with between 40,000 and 70,000 Salafi-jihadist fighters in Syria overall.4
The U.S. goal should be to provide limited funding, training, and assistance to sub-state actors in areas like eastern Syria; contain Russian and Iranian attempts to expand their influence; and conduct strikes against terrorist and other targets.
These debates raise several questions. What are U.S. interests in Syria? And what should a U.S. strategy consist of moving forward? In answering these questions, this report makes two main arguments.
First, U.S. interests in Syria are limited. They include preventing Syria from becoming a sanctuary for Salafi-jihadist groups like the Islamic State and al Qaeda that could threaten the United States and its allies, as well as balancing against Russian and Iranian expansion. Second, based on these interests, the United States should establish a containment strategy in Syria that keeps between several dozen and several hundred military and intelligence personnel in the country—or, at the very least, in neighboring countries like Jordan or Iraq—as well as air and naval assets in the region. Their goal should be to provide limited funding, training, and assistance to sub-state actors in areas like eastern Syria; contain Russian and Iranian attempts to expand their influence; and conduct strikes against terrorist and other targets. A precipitous U.S. withdrawal from Syria in the near term—including an abdication of Washington’s role in the de-confliction zone agreement along the Syrian-Jordanian border, abandonment of U.S. military bases in areas like al-Tanf and Manbij, and desertion of the Syrian Democratic Forces (SDF)—would unnecessarily undermine U.S. interests. Russia and Iran would move into the vacuum, as they have already started to do, just as Washington pulled out of the Iran nuclear deal. The United States would also take an unnecessary risk by weakening its collection capabilities and ability to respond to an al Qaeda or Islamic State resurgence.
Confusing and contradictory policies and statements under the current and past U.S. administrations have tarnished U.S. credibility in the region. A containment strategy that recognizes the current balance-of-power competition in the region would go a long way toward a more consistent and sustainable U.S. approach to Syria and the region.
Balancing against Iran and Russia
U.S. interests in Syria need to be weighed against U.S. interests elsewhere, such as balancing an increasingly powerful China, deterring Russian belligerence in areas like the Baltics, and preventing North Korean nuclear and conventional aggression. In Syria, the United States has limited interests, which should be grounded in a broader regional strategy.
One interest is countering against Iranian and Russian power.5 Both countries are competitors of the United States, and their actions in Syria and the Middle East are often directly at odds with U.S. interests in the region. U.S. actions in Syria should be viewed, in part, through the lens of realist balance-of-power competition with Moscow and Tehran. Balancing includes efforts to check the expansion of states through military, economic, political, and other means.6 But the United States needs to be pragmatic. Russia and Iran have significant interests in Syria, a historical relationship with Damascus, and a determination to keep their own forces and proxies in Syria for the foreseeable future.7 While Moscow and Tehran have cooperated to prevent the overthrow of the Assad regime, they are not strong allies. Figure 1 highlights the Russian, Iranian, and U.S. footprint in Syria. Most of Russia’s military and intelligence units are located in western governorates like Latakia and Tartus, though Russia also has a presence in such eastern governorates as Deir Azzour. Iran and its proxies are located primarily in Syria’s west, northwest, and southwest.
Figure 1: U.S., Russian, and Iranian Force Posture in Syria
Iran: Tehran’s interests in Syria are tied to the broader goals of Iranian leaders, led by Supreme Leader Ayatollah Ali Khameini, to expand their influence in the region and balance against countries like the United States, Israel, and Saudi Arabia.8 Iran hopes to maintain military bases and corridors—or lines of communication—from Iran through Iraq, Syria, and Lebanon.9 To achieve its interests, Iran has adopted a strategy of “forward defense,” which involves supporting sub-state proxies in countries like Syria.10 Iran possesses formidable unconventional capabilities led by the Islamic Revolutionary Guards Corps (IRGC). Of particular note is the IRGC-Quds Force (IRGC-QF), a special operations unit of the IRGC responsible for clandestine activities overseas.11
Since 2011, Iran has supplied money, weapons, equipment, development assistance, and other aid to the Assad regime. Tehran has deployed between several hundred and several thousand soldiers on the ground—from IRGC operatives to regular Iranian army forces—and utilizes locations like Tiyas air base (or T-4) in Homs, Al-Shayrat airfield in Homs, and Al-Kiswah base south of Damascus.12 Iran also supports a variety of pro-regime militias like Hezbollah, which has roughly 6,000 to 8,000 fighters in Damascus, Homs, Aleppo, Hama, and other areas.13 The Hezbollah presence in Syria has been controversial among some Hezbollah supporters because of the high costs in blood and money, as well as concerns that the war in Syria has taken away its focus from priorities in Lebanon.14 In addition, there are perhaps 8,000 to 12,000 other Shia foreign fighters in Iran from countries like Afghanistan, Yemen, Iraq, and Lebanon.15 The IRGC-QF’s external operations department, or Department 400 (also known as the Misaq Unit), has been critical in organizing these militias.
U.S. interests should include balancing against Russian efforts to expand power and influence, including into such countries as Iraq, Lebanon, and Egypt; raising the costs of Russian operations in Syria; and potentially cooperating when Washington and Moscow share common interests, such as targeting some terrorist groups.
U.S. interests should include preventing Iranian forces or militias from pushing too close to the Israeli border, especially with heavy weapons in Al Qunaytirah and Daraa governorates; disrupting Iranian lines of communication through Syria; preventing a significant escalation in the Iranian-Israeli conflict that could trigger broader regional destabilization; and weakening Tehran’s Shia proxy forces that can be used for power projection around the region. It would be a deeply contradictory policy for Washington to pull out of the Iran nuclear deal and, at the same time, to hand Syria to Tehran and Moscow. In addition, the Israeli air strikes against Iranian military targets in Syria in early May highlight the potential for escalation between Israel and Iran.
Russia: Moscow seeks to expand its power and influence in the region, preserve Damascus as a major ally, balance against U.S. power in the region, and target terrorist groups that threaten Russian security.16 To this end, Moscow will likely continue to push for a decisive victory in Syria through military force and, where necessary, limited political negotiations. Russia has provided substantial military, intelligence, and political support to Assad. There are over a dozen Russian military bases or installations, such as at Hmeimim airbase and the port of Tartus (where Moscow signed a 49-year lease in 2017), and approximately 6,000 soldiers and military advisers.17 Russia has also leveraged several private military companies that carry out special missions in Syria, including the paramilitary group ChVK Wagner.18
Though Moscow has used a relatively light footprint compared to past campaigns like Afghanistan in the 1980s, its participation in the Syrian war is its most expansive military operation outside of Europe since the end of the Cold War. Russian forces have been given an unparalleled opportunity to improve their strike, intelligence, combined arms, and training capabilities. Moscow deployed significant military capabilities—such as Su-30SM heavy multirole fighters, Su-25SM/UB attack aircraft, Su-24M2 bombers, Su-34 medium-range bombers, Il-20M1 reconnaissance planes, long-range Tu-22MD bombers, Mi-24P attack helicopters, and Iskander-M short-range ballistic missile systems—which could be used for longer-term power projection in the region. Russia also deployed ships and submarines in the Caspian Sea and Mediterranean Sea from units like the Black Sea Fleet, equipped with Kalibr land-attack cruise missiles and other weapons and systems to strike targets in Syria.19
U.S. interests should include balancing against Russian efforts to expand power and influence, including into such countries as Iraq, Lebanon, and Egypt; raising the costs of Russian operations in Syria; and potentially cooperating when Washington and Moscow share common interests, such as targeting some terrorist groups. Moscow’s involvement in Syria is a sensitive subject in Russia because of the financial costs and casualties of Russian soldiers and private contractors, which the United States should try to better exploit.
Preventing Terrorist Resurgence
Another major U.S. interest is to prevent Syria from becoming a sanctuary for Salafi-jihadist groups like the Islamic State and al Qaeda that threaten the United States and its allies. In 2013 and 2014, the al Qaeda-affiliated Jabhat al-Nusrah gave sanctuary to terrorists like Muhsin al-Fadli and Abdul Mohsen Abdullah Ibrahim al-Sharikh, which U.S. officials referred to as the “Khorasan Group,” to plot attacks in the West.20 In response, the United States and its allies conducted a series of air strikes against Khorasan targets in northwestern Syria, killing al-Fadli and others.
Preventing Syria from becoming a terrorist sanctuary will be a challenge since Syria is currently a haven for Salafi-jihadist and other groups, even with the Islamic State’s loss of territory. As Figure 2 shows, there are roughly 40,000 to 70,000 Salafi-jihadist fighters today in the country with competing aims and objectives.21 The high estimate of Salafi-jihadists has come down slightly from peak levels in 2015 and 2016, but the numbers are still substantial. Many are concentrated in the Idlib area near the Turkish border, though there are also pockets of fighters along Syria’s southern borders with Jordan, around Jarabalus, along the Euphrates River Valley between al-Mayadin and Abu Kamal, and around the Syrian-Iraqi border. There is substantial fluidity within and among these groups. The constant rebranding, fissures between jihadists, splintering, defections, and creation of new groups suggest that there is a pool of jihadists willing to alter their affiliations and organizational structures based on changing leaders, popular support, foreign assistance, and the state of local wars—all of which may rapidly evolve. This fluidity makes it important for the United States to be flexible in responding to a rapidly changing series of terrorist groups and networks.
Figure 2: High and Low Estimates of Salafi-Jihadists in Syria, 2011–2018
Source: Open source estimates compiled by the CSIS Transnational Threats Project.
Some of the most prominent groups include Hay’at Tahrir al-Sham / Jabhat al-Nusrah, Jabhat Tahrir al-Souria, Jaysh al-Islam, and the Islamic State.
Hay’at Tahrir al Sham / Jabhat al-Nusrah: Once a formal affiliate of al Qaeda operating under the name Jabhat al-Nusrah, Mohammad al-Jawlani helped establish Hay’at Tahrir al-Sham in January 2017. The group primarily operates in Idlib governorate and controls between 12,000 and 15,000 fighters, though it also has a presence in areas like Daraa governorate.22 Like other Salafi-jihadist groups, Hay’at Tahrir al-Sham aims to establish an extreme Islamic emirate in the country governed by Islamic law, or sharia. Hay’at Tahrir al-Sham’s relationship with other Salafi-jihadists—including ones more closely aligned with al Qaeda—has been characterized by substantial friction and discord.23 In response, al Qaeda leader Ayman al-Zawahiri has attempted to encourage greater unity among Salafi-jihadist groups in Syria and is attempting a resurgence. Al-Zawahiri has argued that Syria is a cornerstone in establishing an Islamic government in the heart of the Middle East: “I warn our brothers and our people in Sham that their battle is very serious, for it is a battle in the heart of the Arab and Islamic world, and a battle right outside Jerusalem.”24
Al Qaeda’s Struggling Campaign in Syria
How has al Qaeda fared in Syria? What have been its most significant challenges? What do answers to these questions suggest about al Qaeda’s future in Syria and the region?
Jabhat Tahrir al-Souria: Another group is Jabhat Tahrir al-Souria, which includes roughly 15,000 to 25,000 fighters.25 The group was formed by the merger of the Salafi-jihadist group Ahrar al-Sham and the Islamist group Harakat Nour al-Din al-Zinki. Ahrar al-Sham has traditionally been one of Syria’s largest Salafi-jihadist opposition groups and worked closely with Jabhat al-Nusrah against the Assad regime.26 Nour al-Din Al Zinki constitutes a smaller portion of Jabhat Tahrir al-Souria. The group has opportunistically varied its alliances and ideology over time, and it has become more hardline over the course of the conflict.
Jaysh al-Islam: The group Jaysh al-Islam was formed in 2013 through the merger of dozens of opposition groups, including Liwa al-Islam. It has called for the overthrow of the Syrian regime and subscribes to an ideology that includes a mixture of Salafism and Syrian nationalism. Jaysh al-Islam includes between 9,000 and 11,000 fighters. It is mostly active in southern Syria and was largely dislodged from eastern Ghouta, near Damascus.27
Islamic State: While the Islamic State has lost most of the territory it once controlled in Syria, it retains a presence along the Euphrates River Valley between al-Mayadin and Abu Kamal, along the Syrian-Iraqi border, and near Syria’s border with Jordan. The Islamic State works closely with a number of local groups like Jaysh Khalid bin al-Waleed, which is located in Syria’s southwestern governorate of Daraa. Led by Abu Bakr al-Baghdadi, the Islamic State’s long-term goal remains establishing a pan-Islamic caliphate that extends from the Middle East into Africa, Europe, and Asia. It aims to rule by sharia not, as its propaganda notes, by “the laws of men.”28 Islamic State leaders continue to condemn Western societies because of their democratic and liberal values. In an article titled “Why We Hate You and Why We Fight You,” one Islamic State ideologue explained that “your secular liberalism has led you to tolerate and even support ‘gay rights,’ to allow alcohol, drugs, fornication, gambling, and usury to become widespread, and to encourage the people to mock those who denounce these filthy sins and vices.”29 In Syria, the Islamic State primarily operates as a guerrilla organization today and conducts ambushes, raids, and targeted assassinations. Despite the statements by some U.S. policymakers that the group has been crushed, the Islamic State has between 5,000 and 12,000 fighters in Syria.30
Other Groups: There are several other Salafi-jihadist groups and networks in Syria. One is Tanzim Huras al-Deen, a group made up of hardline defectors from Jabhat al-Nusrah, Jabhat Fatah al-Sham, Hay’at Tahrir al Sham, and others loyal to Ayman al-Zawahiri. The group likely has between several hundred and perhaps 3,000 members.31 Its leadership includes Abu Hammam al-Shami, Sami al-Oraidi, and Abu Qassam al-Urdani, all of whom defected from al Qaeda’s former affiliate amid its tribulations with al Qaeda and remain loyal to Zawahiri. Figure 3 highlights thew control of territory in Syria, including the approximate locations of Salafi-jihadist groups.
Figure 3: Control of Territory and Approximate Location of Salafi-Jihadist Groups
Source: IHS Janes and open source data compiled by the CSIS Transnational Threats Project.
U.S. interests should include preventing the resurgence of Salafi-jihadist groups, especially ones linked to the Islamic State or al Qaeda, that may plot external operations against the United States and its allies. One challenge for Washington is that most of the countries operating in Syria—including the Assad regime, Iran, Russia, and Turkey—may not necessarily be viable allies in combating terrorist groups, since they have different interests and priorities. A few, like Turkey, have been willing to support Salafi-jihadists when it serves a broader purpose of targeting Kurdish groups.
In Syria, it is not feasible to eliminate Russian or Iranian influence. Instead, Washington should take steps that check further expansion and ensure that the regional balance of power does not significantly shift in favor of Moscow and Tehran.
A Containment Strategy in Syria
Based on the United States’ limited interests in Syria, Washington should adopt a containment strategy in Syria that involves preventing further expansion of Iranian and Russian power and thwarting the resurgence of Salafi-jihadists that threaten the United States and its allies. Containment includes coercing or deterring a state from expanding its influence. During the Cold War, the U.S. containment strategy involved hindering Soviet expansionism. It took inspiration from George Kennan’s writings in the 1940s and evolved with the publication of NSC-68.32 The goal was not to overthrow the Soviet Union or liberate Eastern Europe but, as Cold War historian John Lewis Gaddis summarized, “to limit Soviet expansionism” on the grounds that “communism posed a threat only to the extent that it was the instrument of that expansion.”33 Successive U.S. administrations sought to maintain a balance of power with the Soviets in hopes that the communist system might ultimately collapse because of its own contradictions and inefficiencies.34
In Syria, it is not feasible to eliminate Russian or Iranian influence. Instead, Washington should take steps that check further expansion and ensure that the regional balance of power does not significantly shift in favor of Moscow and Tehran. U.S. decisions, including the possible withdrawal of forces, should be made with balance-of-power considerations in mind, as described in more detail below. Washington’s policy should include several components.
1. Retain a Small Military and Intelligence Footprint
The United States should keep a limited military and intelligence presence in Syria—or, as a back-up, in neighboring countries like Iraq or Jordan—for the near future. U.S. personnel should retain a relationship with—and provide limited training, funding, and equipment to—groups in eastern, northern, and southern Syria, including the SDF. The United States has developed a close relationship with the SDF, which can play a helpful role in targeting Islamic State sanctuaries and other terrorists in the future. Abandoning the SDF would send an unhelpful signal to future U.S. partners that it will discard them when convenient and it would hand the SDF to Moscow and Damascus. In addition, a U.S. presence could also check Iranian and Russian expansion. Leaving the U.S. base at Al-Tanf, for example, would likely open a southern corridor for Iran to move people and material from Iraq through Syria and into Lebanon, as well as potentially increase refugee flows to Jordan from the Rukban camp along the Jordanian-Syrian border.
A small U.S. military and intelligence presence might include at most several hundred personnel, down from roughly 2,000 troops today. U.S. personnel could include a battalion-sized unit from U.S. Army Special Forces with other elements—such as U.S. Navy SEALS—to train, advise, and assist local forces. In addition, a U.S. force package might include special operations forces that can conduct direct action missions, such as a squadron of “Tier 1” or other task force units from Joint Special Operations Command. If the United States wanted to keep some or all of its presence covert, it might utilize CIA paramilitary forces or U.S. military forces operating under Title 50 authority.35
A small U.S. military and intelligence presence might include at most several hundred personnel, down from roughly 2,000 troops today.
These forces would likely require “enablers.” First, it would be important to have unmanned aerial vehicles (UAVs)—such as ScanEagles and MQ-9 Reapers—to conduct intelligence, surveillance, reconnaissance, and occasional strike missions. In addition, medical evacuation capabilities would be necessary for rapid response. The United States would also need to retain sufficient land- and sea-based capabilities in the region to strike terrorist targets in Syria. These units could be stationed in neighboring countries like Iraq and off-shore in the Persian Gulf or Mediterranean Sea. The United States should retain attack aircraft such as F-15Es, FA-18E/Fs, A-10s, and F-22s to conduct strikes against Islamic State or al Qaeda operatives, infrastructure, vehicles, or training camps. The United States may also decide to use military force for other reasons, such as in response to the Syrian regime’s utilization of chemical weapons. Finally, some intelligence personnel would need to collect and analyze human, signals, and other types of intelligence.
A long-term strategy to work with the SDF and other sub-state networks in Syria would be challenging, though possible. Syrian tribes and clans are far from unified, and many receive support from Saudi Arabia, Russia, the Assad regime, Turkey, and other countries in the region. Syrian tribes also have varying levels of combat experience, divergent capabilities, internecine rivalries, and differing interests. But a U.S. and allied approach that provides modest support may be workable. This might include leveraging the Syrian tribal diaspora in Jordan, Lebanon, Turkey, and other countries in coordination with allied governments like Jordan. Examples include tribes like the Al-Bu Saraya in Deir Azzour, Al-Bu Sha’ban in Raqqah, al Baqqarah in Hassakah and Deir Azzour, Jubbur in Hasakah, Al-Juhaysh in Hasakah, and Ougaidat in Raqqah and Deir Azzour.
The United States has adopted a similar approach in other countries, including working with clans in southern Somalia to balance against al Shabaab, an al Qaeda-affiliated group; tribes and other sub-state actors in Yemen that oppose al Qaeda in the Arabian Peninsula (AQAP) and Iranian-backed Houthi forces; and militias in Libya that are aligned against the Islamic State and other Salafi-jihadists in areas like Sirte and Darnah. This approach is also reminiscent of what the United States did in Afghanistan following the Soviet withdrawal. From the 1990s to 2001, the CIA retained a relationship with—and provided support to—Northern Alliance forces in Afghanistan against the Taliban.36 Following the September 2001 terrorist attacks, the CIA’s relationship with the Northern Alliance was critical to overthrowing the Taliban regime.37
2. Coordinate with Regional Allies
The United States should also leverage its diplomats to work closely with allies in the region, such as Jordan and Israel, to balance against Iran and Russia and to prevent the resurgence of Salafi-jihadists.
One example is close cooperation with Jordan. The United States, Jordan, and Russia established a temporary de-escalation zone in southwestern Syria in 2017 as a buffer to stem the flow of terrorists and further refugees into Jordan, aid refugees in countries like Lebanon and internally displaced persons in Syria, and prevent Hezbollah and other Shia militias from moving close to the Syrian-Israeli border.38 U.S. diplomacy will be critical to help negotiate future arrangements in southern Syria that do not significantly undermine either Jordan’s or Israel’s security. Jordan has legitimate concerns about stemming a major flow of new refugees and terrorists into the country, stabilizing Syria, and reopening trade through border crossings like the Ar Ramtha-Daraa crossing—particularly since Jordan has a fragile economy.39 Jordan also has an interest in preventing the opening of an Iranian corridor if the United States were to shut down its base at Al-Tanf. In addition, the United States should support King Abdullah II of Jordan’s Aqaba Meetings to combat extremist ideologies. Finally, U.S.-Jordanian cooperation is important to work with sub-state actors in Syria, such as the Free Syrian Army, that can help create a buffer from extremist groups.
Jordan has legitimate concerns about stemming a major flow of new refugees and terrorists into the country, stabilizing Syria, and reopening trade through border crossings like the Ar Ramtha-Daraa crossing—particularly since Jordan has a fragile economy.
U.S. cooperation with Israel is also important to balance against Iran and to prevent Hezbollah incursions and a military build-up along the Syrian-Israeli border. Israel has provided money, arms, ammunition, and equipment to local groups like Liwaa’ Fursan al-Jolan and Firqat Ahrar Nawa in southwestern Syria, near the Israeli border.40 Israel has also conducted cross-border strikes on Iranian targets encroaching on the Golan heights and convoys carrying arms to Hezbollah. The de-escalation zone agreement signed by the United States, Russia, and Jordan in 2017 included a promise to keep Iran and its affiliated Shia militias away from the Israeli border, which Hezbollah has repeatedly violated despite Israeli protests.41 Israel also increased its civilian aid to villages controlled by the rebels, including supplying medicine, food, and clothing.42 The United States needs to work closely with Jordanian and Israeli officials where they share common interests.
3. Pressure States to End Support to Salafi-Jihadists
Finally, the United States should increase public and private pressure on governments like Turkey to stop direct and indirect support to Salafi-jihadist groups. In the early stages of the Syrian war, Turkey’s lax border policy made it the main transit route for foreign fighters into Syria.43 Turkey shifted its focus from ousting Assad to expelling Kurdish forces—which have consolidated territory in northern and eastern Syria—from its borders. Starting in October 2017, Turkish soldiers moved into the rebel-held Idlib province and were accompanied by fighters from Hay’at Tahrir al-Sham.44 These actions highlight Ankara’s willingness to align itself with Salafi-jihadists against the perceived greater evil—the Kurds. In March 2018, Turkish-backed fighters seized the northern Syrian city of Afrin, where Kurdish forces had established a sanctuary. Turkey has also threatened to push into Manbij, where the United States maintains military forces.45
In addition, Kuwait has provided money to Salafi-jihadist and other groups in Syria. One fundraising group, the Great Kuwait Campaign, provided assistance to thousands of fighters.46 Qatar and other Gulf states have also supported Salafi-jihadists in Syria. In 2015, Qatar joined Turkey and Saudi Arabia in forging the opposition coalition known as the Army of Conquest, which included factions such as Ahrar al-Sham and the former al Qaeda affiliate Jabhat al-Nusra.47 Qatar has enjoyed a historically close relationship with Jabhat al-Nusrah.48 In response to these actions, the United States needs to use all appropriate departments and agencies of the U.S. government to stop financial and logistical support from countries like Turkey, Kuwait, Qatar, and others.
During his extensive travels in the region in the early twentieth century, the British military officer and diplomat T.E. Lawrence argued that it was critical for Britain to retain a hand in local affairs to protect British interests. “Your ideal position is when you are present and not noticed,” he wrote in his “Twenty-Seven Articles” or Arab warfare.49 The United States should heed this advice, ignore the temptation to cut and run, and keep a light hand in Syria to counter terrorist groups and balance against Russia and Iran.
Seth G. Jones holds the Harold Brown Chair, is director of the Transnational Threats Project, and is a senior adviser to the International Security Program at the Center for Strategic and International Studies in Washington, D.C.
CSIS Briefs are produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).
© 2018 by the Center for Strategic and International Studies. All rights reserved.
 President Donald Trump press conference, April 3, 2018, transcript available at: http://www.cnn.com/TRANSCRIPTS/1804/03/cnr.05.html.
 Julie Hirschfeld Davis, “Trump Drops Push for Immediate Withdrawal of Troops from Syria,” New York Times, April 4, 2018. Also see Robert S. Ford, “Keeping Out of Syria: The Least Bad Option,” Foreign Affairs 96, no. 6 (November/December 2017): 16–22.
 White House, National Security Strategy of the United States of America (Washington, DC: White House, December 2017), 1. In addition, U.S. President Donald Trump remarked that “the United States, under my Administration, has done a great job of ridding the region of ISIS.” Tweet from @realDonaldTrump, April 12, 2018.
 This report defines Salafi-jihadist based on two criteria. First, the individual or group emphasizes the importance of returning to a “pure” Islam, that of the Salaf, the pious ancestors. Second, the group believes that violent jihad is fard ‘ayn (a personal religious duty). The estimates of Salafi-jihadist fighters are from the Transnational Threats Project’s Salafi-jihadist database.
 See Jon B. Alterman and Heather A. Conley, “Syria, Turkey, and the Eastern Mediterranean,” CSIS Briefs, April 19, 2018, available at: https://www.csis.org/analysis/syria-turkey-and-eastern-mediterranean.
 On the balance-of-power competition, see Hans J. Morgenthau, Politics Among Nations: The Struggle for Power and Peace, 7th ed. (New York: McGraw-Hill, 2005); Kenneth N. Waltz, Theory of International Politics (New York: McGraw-Hill, 1979); John J. Mearsheimer, The Tragedy of Great Power Politics (New York: W.W. Norton, 2001).
 Moscow, for example, began to support Syria after the 1956 Suez Crisis and then significantly increased its strategic relationship in 1971 under Syrian President Hafez al-Assad.
 See, for example, Misagh Parsa, Democracy in Iran: Why It Failed and How It Might Succeed (Cambridge, MA: Harvard University Press, 2016); Abbas Amanat, Iran: A Modern History (New Haven, CT: Yale University Press, 2017).
 Emil Avdaliani, Iran and the New Land Corridor (Ramat Gan, Israel: Begin-Sadat Center for Strategic Studies, December 19, 2017).
 Vali Nasr, “Iran Among the Ruins: Tehran’s Advantage in a Turbulent Middle East,” Foreign Affairs 97, no. 2 (March/April 2018): 111.
 Linda Robinson et al., Modern Political Warfare: Current Practices and Possible Responses (Santa Monica, CA: RAND, 2018), 125–70.
 Ben Hubbard, Isabel Kershner, and Anne Barnard, “Iran, Deeply in Syria, Expands ‘Axis of Resistance,’” New York Times, February 19, 2018.
 See, for example, U.S. State Department, Country Reports on Terrorism 2016 (Washington, DC: U.S. Department of State, Bureau of Counterterrorism, July 2017), 404; Hubbard, Kershner, and Barnard, “Iran, Deeply in Syria, Expands ‘Axis of Resistance’”; the Hezbollah section in U.S. Department of State, “Chapter 6: Foreign Terrorist Organizations,” Bureau of Counterterrorism and Countering Violent Extremism, 2016, available at: https://www.state.gov/j/ct/rls/crt/2016/272238.htm. On Hezbollah more broadly, see Joseph Daher, Hezbollah: The Political Economy of Lebanon’s Party of God (New York: Pluto Press, 2016); Matthew Levitt, Hezbollah: The Global Footprint of Lebanon's Party of God, rev. ed. (Washington, DC: Georgetown University Press, 2015).
 See, for example, Majid Rafizadeh, “Iran’s Fighters Are Dying in Syria—Will It Change Anything?,” Huffington Post, December 6, 2017; Jesse Rosenfeld, “Hezbollah Fighters Are Fed Up with Fighting Syria’s War,” Daily Beast, December 30, 2015.
 Phillip Smyth, Iran Is Outpacing Assad for Control of Syria’s Shia Militias (Washington, DC: Washington Institute for Near East Policy, April 12, 2018).
 Moscow’s direct involvement in Syria began in 2015. On the Russian strategy in Syria see, for example, “Comments by Russian President Vladimir Putin to the UN General Assembly,” Military Review 96, no. 1 (January-February 2016): 16–21; Michael Kofman and Matthew Rojansky, “What Kind of Victory for Russia in Syria?,” Military Review 98, no. 2 (March-April 2018): 6–23; and Michael Kofman, “The Moscow School of Hard Knocks: Key Pillars of Russian Strategy,” War on the Rocks, January 17, 2017.
 CSIS estimates; Ayman Aldassouky, Russia’s Brittle Strategic Pillars in Syria (London: Royal Institute of International Affairs, December 2017).
 Aldassouky, Russia’s Brittle Strategic Pillars in Syria.
 See, for example, Kofman and Rojansky, “What Kind of Victory for Russia in Syria?,” 6–23; John W. Parker, Putin’s Syrian Gambit: Sharper Elbows, Bigger Footprint, Stickier Wicket (Washington, DC: Institute for National Strategic Studies, National Defense University, July 2017); Ruslan Pukhov, “Russian Military, Diplomatic and Humanitarian Assistance” in Syrian Frontier, ed. M. U. Shepovalenko, 2nd ed. (Moscow: Center for Analysis of Strategies and Technologies, 2016), 105–107.
 See, for example, Mark Mazzetti, “A Terror Cell That Avoided the Spotlight,” New York Times, September 24, 2014.
 The data are from the Transnational Threats Project’s Salafi-jihadist database at CSIS.
 The data are from the Transnational Threats Project’s Salafi-jihadist database at CSIS.
 See, for example, “The Commission between the Letter of Disclosure and Advice and a Letter of Praise and Justification,” http://www.jihadica.com/wp-content/uploads/2017/03/al-Haya-bayna-khitab.pdf; and Sami al-Oraidi’s comments in Aymenn Jawad al-Tamimi, “The Hay’at Tahrir al-Sham-al-Qaeda Dispute: Primary Texts (I),” December 6, 2017, http://www.aymennjawad.org/2017/12/the-hayat-tahrir-al-sham-al-qaeda-dispute-primary.
 Ayman al-Zawahiri, “O Our Brothers in Sham, Reconcile Among Yourselves,” As-Sahab Media Foundation, released on February 20, 2018; “Al-Qaeda Leader Zawahiri Reiterates Call for Unity in Syria, Tells Fighters to Prepare for Decades-Long War,” SITE Intelligence Group, February 20, 2018.
 The data are from the Transnational Threats Project’s Salafi-jihadist database at CSIS.
 Jamie Dettmer, “Syria’s Saudi Jihadist Problem,” Daily Beast, December 16, 2013.
 The data are from the Transnational Threats Project’s Salafi-jihadist database at CSIS. Also see “Jaysh al-Islam,” Mapping Militant Organizations, Stanford University, available at: http://web.stanford.edu/group/mappingmilitants/cgi-bin/groups/view/533.
 “The Laws of Allah or the Laws of Men,” Dabiq, No. 10, 1436 Ramadan, 50–64.
 “Why We Hate You and Why We Fight You,” Dabiq, No. 15, 1437 Shawwal, 32.
 Michael R. Gordon, “U.S. Seeks Arab Force and Funding for Syria,” Wall Street Journal, April 16, 2018; Transnational Threats Project’s Salafi-jihadist database at CSIS.
 The data are from the Transnational Threats Project’s Salafi-jihadist database at CSIS.
 X, “The Sources of Soviet Conduct,” Foreign Affairs 25, no. 4 (1947): 566–82; NSC, “A Report to the National Security Council by the Executive Secretary on United States Objectives and Programs for National Security,” NSC-68, April 14, 1950.
 John Lewis Gaddis, Strategies of Containment: A Critical Appraisal of Postwar American National Security Policy (New York: Oxford University Press, 1982), 34.
 John Lewis Gaddis, We Now Know: Rethinking Cold War History (New York: Oxford University Press), 1997, 39.
 As explained under the U.S. Code, a Title 50 operation means that the mission comes under CIA authority. U.S. military forces can come under CIA command, as they did in 2011 during the Osama bin Laden raid. As the U.S. Code notes, “The term ‘covert action’ means an activity or activities of the United States Government to influence political, economic, or military conditions abroad, where it is intended that the role of the United States Government will not be apparent or acknowledged publicly, but does not include . . . traditional . . . military activities or routine support to such activities.” See 50 U.S.C. §413b(e).
 See the declassified assessments of the relationship between the CIA and Northern Alliance before 9/11 in The 9/11 Commission Report (New York: W.W. Norton, 2004).
 See, for example, Gary C. Schroen, First In: An Insider’s Account of How the CIA Spearheaded the War on Terror in Afghanistan (New York: Ballantine Books, 2005); Gary Berntsen and Ralph Pezzullo, Jawbreaker: The Attack on Bin Laden and Al-Qaeda (New York: Crown Publishers, 2005).
 “Jordan Does Not Want Terrorists or Sectarian Militias at Border,” Jordan Times, April 22, 2018.
 Jordan’s economy remains in a low-growth situation with gross domestic product expected to increase by 2.4 percent in 2018 and 2.5 percent in 2019 from 2.1 percent in 2017. Unemployment is at roughly 18.5 percent. Jordan’s economy has been impacted by the war in Syria, which has impacted trade flows; slow revival of economic cooperation with Iraq; and an economic slowdown in the Gulf Cooperation Council (GCC). World Bank, Jordan's Economic Outlook: April 2018 (Washington, DC: World Bank, April 16, 2018).
 Elizabeth Tsurkov, “Israel’s Deepening Involvement with Syria’s Rebels,” War on the Rocks, February 14, 2018.
 Amos Harel, “To Push Iran Back, Israel Ramps Up Support for Syrian Rebels, ‘Arming 7 Different Groups,’” Haaretz, February 21, 2018.
 Tsurkov, “Israel’s Deepening Involvement with Syria’s Rebels.”
 U.S. Department of State, Country Reports on Terrorism 2015 (Washington, DC: U.S. Department of State, 2016), 89, 156–60.
 Charles Lister, “Turkey’s Idlib Incursion and the HTS Question: Understanding the Long Game in Syria,” War on the Rocks, October 31, 2017.
 See, for example, Carlotta Gall and Anne Barnard, “Syrian Rebels, Backed by Turkey, Seize Control of Afrin,” New York Times, March 18, 2018; “Turkish Military Operation in Syria’s Afrin Has Begun: Erdogan,” Reuters, January 20, 2018.
 “Remarks of Under Secretary for Terrorism and Financial Intelligence David Cohen before the Center for a New American Security on ‘Confronting New Threats in Terrorist Financing,’” March 4, 2014, https://www.treasury.gov/press-center/press-releases/Pages/jl2308.aspx; Andrew Gilligan, “How Our Allies in Kuwait and Qatar Funded Islamic State,” Telegraph, September 6, 2014.
 David Ignatius, “A New Cooperation on Syria,” Washington Post, May 12, 2015.
 Jay Solomon and Nour Malas, “Qatar’s Ties to Militants Strain Alliance,” Wall Street Journal, February 23, 2015; Andrew Gilligan, “The ‘Club Med for Terrorists,’” Telegraph, September 27, 2014.
 T.E. Lawrence, “The 27 Articles of T.E. Lawrence,” The Arab Bulletin, August 20, 1917.