Contents

• Overview
• FY2017 Legislation and Issues for Congress
• Debating Measures to Protect Civilians in Syria's Civil War
• Conflict Synopsis
• Russia's Military Intervention
• Recent Developments
• Military
• Aleppo
• Turkey and Operation Euphrates Shield
• SDF Operations to Isolate Raqqah
• Political
• Failure of Cessations of Hostilities in 2016
• Prospects for Peace Negotiations
• The Russia/Turkey/Iran Initiative
• Humanitarian Situation
• U.S. Policy and Assistance
• U.S. Strategy and Policy
• Viability of the Syrian State
• Proposals for a Safe Zone
• Congressional Debate
• FY2017 Budget Requests for Syria
• Combatting the Islamic State in Syria
April 2017 Chemical Weapons Attack and U.S. Response
• Presidential Authority to Strike Syria Under U.S. Law
• Issues for Congress and Select Pending Legislation
• Select Proposed Syria-Related Legislation
• Conflict Synopsis
• Russia's Military Intervention
• Recent Developments
• Military
• SDF Operations to Isolate Raqqah
• Ongoing U.S. Presence in Manbij
• Turkish-Supported Operations in Syria
• Anti-Asad Groups Battle, Reorganize in Northern Syria
• Political Negotiations
• The Geneva Process
• The Astana Process
• Humanitarian Situation
• U.S. Humanitarian Assistance
• U.S. Policy and Assistance
• U.S. Strategy and Policy
• U.S. Assistance to Syrians and the Syrian Opposition
• Nonlethal Assistance to Armed Syrian Opposition Elements
• Syria Train and Equip Program
• Other Reported U.S. Assistance
• Chemical Weapons and Disarmament
• Outlook

Tables

• Table 1. FY2016 and Proposed FY2017 Authorities for U.S. Foreign Assistance to Syrians

Appendixes

• Appendix A. Syrian History and Demographics
• Appendix B. Parties to the Conflict

Summary

The rise of theRaqqah Operations

Figure 3. Syria-Turkey Border

Summary

A deadly chemical weapons attack in Syria on April 4, 2017, and a U.S. military strike in response on April 6 have returned the Syrian civil war—now in its seventh year—to the forefront of international attention. In response to the April 4 attack, some Members of Congress called for the United States to conduct a punitive military operation. These Members and some others since have praised President Trump's decision to launch a limited strike, with some calling on the President to consult with Congress about Syria strategy. Other Members have questioned the President's authority to launch the strike in the absence of specific prior authorization from Congress. In the past, some in Congress have expressed concern about the international and domestic authorizations for such strikes, their potential unintended consequences, and the possibility of undesirable or unavoidable escalation.

Since taking office in January 2017, President Trump has stated his intention to "destroy" the Syria- and Iraq-based insurgent terrorist group known as the Islamic State (IS, also known as ISIL, ISIS, or the Arabic acronym Da''esh), and the President has ordered actions to "accelerate" U.S. military efforts against the group in both countries. In late March, senior U.S. officials signaled that the United States would prioritize the fight against the Islamic State and said that Syrian President Bashar al Asad's future would be determined by the Syrian people. Nevertheless, in the wake of the April 4 attack, President Trump and senior members of his Administration have spoken more critically of Asad's leadership, and it remains to be seen whether the United States will more directly seek to compel Asad's departure from power while pursuing the ongoing campaign against the Islamic State.

Since late 2015, Asad and his government have leveraged military, financial, and diplomatic support from Russia and Iran to improve and consolidate their position relative to the range of antigovernment insurgents arrayed against them. These insurgents include members of the Islamic State, Islamist and secular fighters, and Al Qaeda-linked networks that are working to integrate themselves with others in opposition-held areas of northwestern Syria. While Islamic State forces have lost territory to the Syrian government, to Turkey-backed Syrian opposition groups, and to U.S.-backed Syrian Kurdish and Arab fighters since early 2016, they remain capable and dangerous. The IS "capital" at Raqqah has been isolated, but large areas of central and eastern Syria remain under the group's control. The presence and activities of Russian military forces and Iranian personnel in Syria create complications for U.S. officials and military planners, and raise the prospect of inadvertent confrontation with possible regional or global implications.

Since March 2011, the conflict has driven more than 5 and Russia's military intervention on behalf of the Syrian government have reshaped debates over U.S. policy toward the ongoing civil conflict in Syria, now in its sixth year. The Islamic State controls large areas of northeastern and central Syria, from which it continues to launch assaults on forces opposed to and aligned with the government of President Bashar al Asad. Meanwhile, fighting elsewhere pits government forces and their foreign allies against a range of anti-government insurgents, some of whom receive limited U.S. assistance. Russian military intervention in support of Asad poses a direct challenge to U.S. goals in Syria, and has raised new questions about the future of the conflict and U.S. strategy.

Since March 2011, the conflict has driven more than 4.8 million Syrians into neighboring countries as refugees (out of a total population of more than 22 million). More than 6.3 million other Syrians are internally displaced and are among more than 13.5 million Syrians in need of humanitarian assistance. The United States remains the largest bilateral provider of such assistance, with almost $6more than $6.5 billion in U.S. funding identified to date. The United States also has allocated more than $500 million to date for assistance programs in Syria, including the provision of nonlethal equipment to select opposition groups. President Obama requested $238.5 million in FY2017 funding for such assistance. The Administration also requested $250Together, the Obama and Trump Administrations have requested $430 million in FY2017 defense funds for its Syria Train and Equip program.

Syrian officials and their Russian and Iranian backers have stated their conditional willingness to serve as "counterterrorism" partners of the United States in Syria, provided that U.S. officials accept a role for the Asad government as a bulwark against Sunni Islamist extremism. Although U.S. officials had previously described a "fundamental strategic disagreement" with Russia over Syria and Asad's future, in 2016 the Obama Administration explored the possibility of cooperation with Russia against terrorist groups in Syria in conjunction with efforts to obtain a lasting cessation of hostilities between pro-Asad forces and armed opposition groups. These efforts were generally viewed as unsuccessful, lacking both enforcement and accountability mechanisms.

U.S. officials and Members of Congress continue to debate how best to pursue U.S. regional security and counterterrorism goals in Syria without inadvertently strengthening Asad, the Islamic State, or other anti-U.S. armed Islamist groups. Anti-Asad armed forces and their activist counterparts share antipathy toward Russian and Iranian intervention, but they remain divided over tactics, strategy, and their long-term political goals. Powerful Sunni Islamist forces seek outcomes that are contrary in significant ways to stated U.S. preferences for Syria's political future.

Some Members of Congress and observers have argued that the United States should seek to compel Asad to negotiate or act militarily to protect Syrian civilians. Others have expressed concern that disorderly regime change could further empower extremists or that civilian protection missions could prolong the conflict or involve the United States too deeply in long-term stabilization. The policies of President-elect Donald Trump and his Administration remain to be determined and articulated and may pose new questions for Members of the 115^th Congress.

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Overview

The resilience of the Islamic State (IS, also known as ISIS/ISIL or by the Arabic acronym Da'esh) and Russia's ongoing military intervention on behalf of President Bashar al Asad's government have reshaped debates over U.S. policy toward the ongoing civil conflict, which has driven more than 4.8 million Syrians into neighboring countries as refugees. The Islamic State controls large areas of northeastern and central Syria, from which it continues to launch assaults on forces aligned with the Asad government as well as other armed groups, including some who oppose the government. Fighting elsewhere pits government forces and their foreign allies (chiefly Russia, Iran, Lebanese Hezbollah, and Iraqi Shia militia groups) against a range of anti-government insurgents, some of whom have received limited U.S. assistance. U.S. and Turkish military operations in northwest Syria have severed the group's remaining access to the Turkish border. While progress has been made in reducing the amount of territory held by IS fighters in both Syria and Iraq, competition and discord between and among local actors in both countries continue to create complications for U.S. officials, as does intervention by and competition among regional and extra-regional actors, including Russia, Iran, Turkey, and Arab Gulf states.

In Congress, Members have weighed the relative risks and rewards of action in Syria against the Islamic State and the Asad government while conducting oversight of U.S. lethal and nonlethal assistance to vetted members of select opposition groups, including the provision of military training, arms, and defensive protection. President Obama's FY2017 budget requests for foreign operations and defense sought more than $4 billion in Syria- and Iraq-related assistance funding for programs in those two countries and the surrounding region. The 114^th Congress also considered proposals to authorize the use of military force against the Islamic State organization.

The negative effects of the humanitarian and regional security crises emanating from Syria appear to be beyond the power of any single actor, including the United States, to independently contain or fully address. The region-wide flood of Syrian refugees, the growth of armed extremist groups in Syria, and the spread of conflict to neighboring Lebanon and Iraq have negatively affected overall regional stability. To date, U.S. policymakers and their counterparts have appeared to feel both compelled to respond to these crises and cautious in considering potentially risky options for doing so, such as the commitment of military combat forces or the provision of large-scale material assistance to armed elements of the opposition. Russia's forceful entrance into the conflict in 2015 bolstered flagging pro-Asad forces, but may not fundamentally change the ability of the Asad government to reassert control over all of Syria. In light of these conditions and trends, Congress may face tough choices about U.S. policy toward Syria and related U.S. relief and security assistance programs for years to come.

FY2017 Legislation and Issues for Congress

The 114^th Congress considered FY2017 appropriations and defense authorization legislation related to Syria, and debated proposals to authorize the use of military force against the Islamic State. Key issues under consideration in relation to legislation include:

• What is the United States' overall strategy toward the Syria conflict in general and toward the Islamic State in Syria and the Asad government in particular? Members of Congress continue to express a range of views concerning U.S. strategy toward the conflict in Syria, combatting the Islamic State, and coordinating responses to the crises in Iraq and Syria. Several legislative proposals in the 114^th Congress called on the Administration to provide Congress with new or updated strategy reports on these topics.
• What authority and funding should be provided for U.S. assistance to Syrians, including assistance to opposition elements? While some proposals to rescind funding and authority for the Syria Train and Equip program have thus far failed to garner sufficient congressional support for enactment, Members continue to debate the proper scope, pace, and goals of the program, especially in light of reports of past program setbacks. The overarching authority for the program provided in the FY2015 National Defense Authorization Act (NDAA, P.L. 113-291) was extended by the 2017 NDAA (P.L. 114-328) until December 31, 2018.
• How, if at all, should the United States respond to calls for a no-fly zone or safe zones for the protection of civilians in areas of Syria? The terms of the cessation of hostilities negotiated by the United States and Russia in 2016 called for the end of Syrian combat operations over opposition-held areas. Widespread violations of the agreement by Syrian and Russian forces (and some violations on the part of Syrian rebels) renewed debate over whether the United States should undertake unilateral military action to protect Syrian civilians.
• What responsibility does the United States have to protect U.S.-backed forces that come under attack? The Obama Administration committed to protecting forces receiving U.S. training and assistance, including train and equip program participants and select Kurdish and non-Kurdish forces. To date, various Syrian forces trained or equipped by the United States have come under attack by the Syrian government, Russia, the Nusra Front (now known as Jabhat Fatah al Sham), the Islamic State, and Turkey—with varied U.S. responses.
• Can the United States exert additional pressure on the Syrian government? Members continue to debate additional measures that might be effective in reducing Syrian government violence. H.R. 5732 (known as the Caesar Syria Civilian Protection Act of 2016) would require the President to impose sanctions on foreign persons and entities that finance, do business with, support, or act on behalf of the Syrian government or government-controlled entities. The executive branch has many of these authorities under existing executive orders and national emergencies and has implemented them at its discretion. The bill passed the House in November 2016.
to train and equip anti-IS forces in Syria.

U.S. officials and Members of Congress continue to debate how best to pursue U.S. regional security and counterterrorism goals in Syria without inadvertently strengthening U.S. adversaries or alienating U.S. partners. The Trump Administration and Members of the 115^th Congress—like their predecessors—face challenges inherent to the simultaneous pursuit of U.S. nonproliferation, counterterrorism, civilian protection, and stabilization goals in a complex, evolving conflict.

Armed Conflict in Syria: Overview and U.S. Response

Overview

After six years of conflict, the challenges posed to U.S. national security by the conflict in Syria have multiplied and evolved. Initial political unrest and the Syrian government's violent response fueled U.S. concerns about Syria's stability and civilian protection in the midst of the 2011 "Arab Spring." The country's subsequent descent into brutal war created a multifaceted regional security crisis, marked by the mass displacement of civilians, the emergence and empowerment of violent armed Islamist extremist groups, gross human rights abuses and war crimes, the use of chemical weapons, the proliferation of arms, and the covert and overt intervention of outside actors. Over time, U.S. policymakers have appeared to feel both compelled to respond to these interlocking crises and cautious in considering potentially risky options for doing so, such as the commitment of military combat forces or the provision of lethal assistance to Syrian combatants. The Obama Administration supported various partner forces in Syria, while calling for Asad's ouster through a negotiated transition.

Russia's forceful entrance into the conflict in 2015 bolstered flagging Syrian government forces, but has yet to enable President Bashar al Asad to reassert control over all of Syria. Government forces and their foreign allies (chiefly Russia, Iran, Lebanese Hezbollah, and Iraqi Shia militia groups) have gained at the expense of their various insurgent adversaries since late 2015, but armed opposition groups continue to control territory and durable political and military solutions remain elusive. Progress has been made by various parties in reducing the amount of territory held by the Islamic State, but competition and discord among local, regional, and extraregional actors continues to create complications for U.S. officials. As of 2017, principal U.S. concerns focus on combatting the Islamic State (IS, also known as ISIS/ISIL or by the Arabic acronym Da'esh) and other Syria-based extremists, while seeking a resolution to the underlying conflict.

In Congress, Members have weighed the relative risks and rewards of various proposed courses of action against the Islamic State and the Asad government while conducting oversight of U.S. assistance programs and military operations. To date, the United States has directed more than $6.5 billion toward Syria-related humanitarian assistance, and Congress has appropriated billions more to support security and stabilization initiatives in Syria and in neighboring countries. The Defense Department has not disaggregated the costs of military operations in Syria from the overall cost of Operation Inherent Resolve, which has reached over $11.7 billion. As of late 2016, Congress had approved the use of more than $1.3 billion to train and equip vetted Syrians as part of a specially authorized program in place since late 2014. Congress also has debated proposals to authorize or restrict the use of military force against the Islamic State and in response to Syrian government chemical weapons attacks, but has not enacted any Syria-specific force authorizations.

An April 2017 chemical weapons attack in Syria and resulting U.S. missile strikes are rekindling debates in Congress about Syria policy, and these debates may intensify as the Trump Administration considers its options and further articulates its goals and strategy. Operations against the Islamic State are focused on the isolation and recapture of the city of Raqqah. After Raqqah, U.S. military officials and local partners may move against IS strongholds in the eastern Euphrates River valley, including areas adjacent to the Iraqi border. The 115^th Congress is considering FY2017 appropriations legislation and FY2018 appropriations and authorization legislation related to Syria, and may engage in renewed debate about overall U.S. strategy while considering current and forthcoming Trump Administration funding requests.

Immediate debates and developments notwithstanding, the degree of devastation and displacement already wrought by the conflict in Syria is overwhelming and may take Syrians and their neighbors decades to overcome. This context and the ongoing intersection in Syria of multiple U.S. national security interests suggest that Congress may face tough choices about U.S. Syria policy and related U.S. relief and security assistance programs for years to come.

April 2017 Chemical Weapons Attack and U.S. Response On April 4, 2017, Syrian aircraft operating in rebel-held Idlib province conducted several airstrikes using what U.S. officials assessed to be a chemical nerve agent.¹ Initial reports suggest that the strikes killed roughly 80 to 100 people in the town of Khan Sheikhoun (see map, Figure 1), including children, and affected several hundred others. While Syrian and Russian officials blamed the deaths on rebel fighters, claiming that Syrian airstrikes hit a warehouse containing rebel-manufactured chemical weapons, U.S. officials attributed the use of chemical weapons to the Syrian government. On April 6, the United States fired 59 Tomahawk missiles at Al Shayrat airfield in Homs province (see map, Figure 1), from which U.S. intelligence sources had concluded the Khan Sheikhoun attack was launched.² U.S. military officials stated that the strikes targeted Syrian aircraft and infrastructure. Speaking on April 6, President Trump said:

Tonight, I ordered a targeted military strike on the airfield in Syria from where the chemical attack was launched. It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons. There can be no dispute that Syria used banned chemical weapons, violated its obligations under the Chemical Weapons Convention, and ignored the urging of the U.N. Security Council.

A Defense Department statement said the U.S. strike "targeted aircraft, hardened aircraft shelters, petroleum and logistical storage, ammunition supply bunkers, air defense systems, and radars" and that "the strike was intended to deter the regime from using chemical weapons again."³ While Russia established a presence at Al Shayrat airfield in late 2015,⁴ U.S. military officials stated that there were no Russian aircraft present at the time of the strikes, and said Russian facilities and personnel were not targeted.⁵ U.S. military officials stated that Russian military personnel were informed prior to the attack, via an established deconfliction channel. A Defense Department assessment released on April 10 stated that the U.S. strike "resulted in the damage or destruction of fuel and ammunition sites, air defense capabilities, and 20 percent of Syria's operational aircraft."⁶

The Syrian military released a statement describing the strikes against Al Shayrat as an "act of aggression," which killed six people and caused "huge material damage."⁷ Syrian state media reported that some U.S. missiles struck nearby villages, killing nine civilians, including children.⁸ CRS cannot verify these reports. A spokesperson for Russian President Vladimir Putin said that the president considered the attacks to be an act of aggression against a sovereign state in violation of the norms of international law, and said the U.S. strike "impairs" U.S.-Russian relations.⁹ U.S. military officials stated that Russia had notified them of its intent to suspend communications via the deconfliction channel, which was established to help the two states avoid conflict between their respective forces operating in Syria. A Russian spokesperson told reporters that Russia would keep military channels of communication open with the United States, but would not provide any information through them.¹⁰

President Trump did not formally seek congressional authorization prior to ordering the attack. Reports suggest that some Members of Congress were notified as the strikes were underway. While some Members praised the U.S. strikes, several have called upon the Administration to consult Congress on U.S. strategy in Syria and on any more expansive or persistent military operations in Syria beyond ongoing counterterrorism missions. Some Members have questioned whether the strike had sufficient domestic or international legal justification.

It is unclear what, if any, impact the strikes may have on the Syrian government's calculus or on its broader military or political strategy. It remains to be seen whether a limited U.S. strike on a military airfield in central Syria will significantly alter the pace or effectiveness of Syrian airstrikes—the vast majority of which are conducted with conventional rather than chemical weapons. On April 7, a Syrian human rights organization reported that two aircraft took off from Al Shayrat and struck targets near the city of Palmyra.¹¹ The Syrian government has continued airstrikes against rebel-held areas, including Khan Sheikhoun.¹² It is unclear whether Syrian or Russian forces will seek to further escalate tensions by targeting U.S. military personnel or U.S.-backed local forces operating in Syria. American officials stated that U.S. military activities in Syria have been slightly adjusted to strengthen the protection of U.S. forces.¹³

U.S. decisionmakers may consider options for responding to any Russian efforts to repair Syrian military infrastructure and replace aircraft and materiel lost in the U.S. strike. Russia may also seek to further employ or strengthen its Syria-based air defense networks. If the Asad government were to use chemical weapons again, U.S. officials might face questions about whether the United States should take more punitive or disruptive measures as a deterrent, with uncertain implications for the viability of pro-Asad forces in the broader conflict and for U.S. relations with Russia and Iran.

Trump Administration officials reportedly have assured Members of Congress that the April 6 strikes were not the planned start of an extended military campaign against the Syrian government.¹⁴ Speaking at the U.N. Security Council on April 7, U.S. Permanent Representative to the United Nations Ambassador Nikki Haley said,

The United States will no longer wait for Assad to use chemical weapons without any consequences. Those days are over. But now we must move to a new phase, a drive toward a political solution to this horrific conflict. We expect the Syrian regime and its allies to take the U.N. political process seriously, something they have not done up until this point. We expect Russia and Iran to hold their ally accountable and abide by the terms of the cease-fire. We expect this Council to speak loudly and forcefully when the regime or its allies undermine the political process and countless of our own resolutions. The United States took a very measured step last night. We are prepared to do more, but we hope that will not be necessary. It is time for all civilized nations to stop the horrors that are taking place in Syria and demand a political solution.¹⁵

Figure 1. Syria: Areas of Influence

Source: CRS using area of influence data from IHS Conflict Monitor, last revised April 4, 2017. All areas of influence approximate and subject to change. Other sources include UN OCHA, Esri and social media reports.

Presidential Authority to Strike Syria Under U.S. Law¹⁶

In an April 8, 2017, letter to Congress, President Trump stated that he had acted "pursuant to my constitutional authority to conduct foreign relations and as Commander in Chief and Chief Executive" in ordering the April 6, 2017, U.S. missile strikes on Al Shayrat airbase in Syria. In the letter, President Trump says that he "acted in the vital national security and foreign policy interests of the United States," and that, "the United States will take additional action, as necessary and appropriate, to further its important national interests." On April 6, the President said he ordered the strikes to protect the "vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons." The April 8 letter expands upon this explanation.¹⁷ In the past, Presidents have justified the use of military force by relying on presidential powers they assert are inherent under Article II Commander in Chief and Chief Executive authority, claiming that a President may use military force to defend U.S. national security interests (even when an immediate threat to the United States and its Armed Forces is not necessarily apparent) and to promote U.S. foreign policy.

In 2013, the Senate Foreign Relations Committee considered and reported a proposed authorization for the use of military force following a chemical weapons attack in the suburbs of Damascus, Syria (S.J.Res. 21). The Senate did not consider the measure further.

Since U.S. military action against the Islamic State began in June 2014, starting in Iraq and then spreading to Syria, Congress has debated the need for enactment of a new IS-specific authorization for use of military force. President Obama eventually asserted that the campaign against the Islamic State in Iraq and Syria was authorized by both the Authorization for Use of Military Force (2001 AUMF; P.L. 107-40; claiming that the Islamic State was a successor organization of Al Qaeda and that elements of Al Qaeda were present in Syria) and Authorization for Use of Military Force Against Iraq Resolution of 2002 (2002 AUMF; P.L. 107-243; claiming authority to defend Iraq from the Islamic State threat). Neither the 2001 or 2002 AUMFs, nor any IS-specific AUMF proposals, however, have been interpreted to authorize the use of military force against the Asad regime in Syria.

Issues for Congress and Select Pending Legislation

Key issues under consideration in Congress relative to Syria include:

• What is the United States' overall strategy toward the Syria conflict in general and toward the Asad government and Islamic State in Syria in particular?
• What domestic and international authority exists for the use of U.S. military force in Syria against various adversaries?
• What authorities and funding should be provided for U.S. assistance to Syrians, including assistance to opposition elements?
• What might be the second- and third-order effects of the U.S. decision to strike Syrian military targets in retaliation for the use of chemical weapons? What implications might the strike have for other U.S. military operations in Syria or for diplomatic efforts to bring an end to the conflict? How, if at all, should the United States respond to any future chemical weapons attacks in Syria?
• How, if at all, should the United States respond to calls for a no-fly zone or safe zones for the protection of civilians in areas of Syria?
• How can the United States exert additional pressure on the Syrian government to reduce the level of violence?
To what extent should the United States seek cooperation with Russia and Iran
• To what extent should the United States seek cooperation with Russia, Turkey, and/or Iran in order to promote a political settlement and reduce levels of violence? U.S. officials have encouraged Russia to use its leverage with the Syrian government to reduce strikes against civilian targets, but to date U.S. attempts to cooperate with Russia on this effort have not resulted in significant reductions in Syrian government strikes. At the same time, Russian military operations in Syria have created new operational considerations for the ongoing coalition air campaign against the Islamic State as well as for proposals for other types of intervention, including the establishment of safe zones or no-fly zones.

These issues are discussed in more detail below (see "U.S. Policy and Assistance").

Debating Measures to Protect Civilians in Syria's Civil War

During the course of the Syrian civil war, debates have continued concerning various proposals for the protection of civilians inside Syria and the delivery of humanitarian assistance to populations in need. In particular, debates have focused on additional measures involving the use of military force to establish areas safe for civilians or to allow for the unimpeded delivery of humanitarian assistance. Opponents of such measures have raised concerns about unintended consequences, the potential for operational success, and the implications of potentially violating Syrian sovereignty through such actions.

Consideration of proposals over time has been complicated by the fluid and violent nature of the conflict, the number and variety of distinct armed forces on the ground, and geopolitical competition among outside actors. These factors further complicate efforts to define the potential scope, costs, risks, and rewards of various proposals.

As a consequence, proposals to enhance civilian protection vary greatly. In considering current and future proposals for the protection of civilians in Syria, relevant questions include:

• What specific measures are being proposed? What alternatives exist?
• On what international and domestic authority would such measures proceed? What implications might unilateral measures have for international law and relations among international powers?
• In what geographic areas would such measures apply? From what geographic areas would such measures be implemented? Which governments' and groups' interests would be affected?
• Which actors have the capabilities and willingness to implement such measures?
• Who might oppose such measures? How and at what potential risk to implementers?
• What unintended consequences might result? How, if at all, might the protection provided under international humanitarian law be undermined?
• What might be the impact on humanitarian operations, access, and security?
• How long would such measures last? At what cost? To whom?
• What might be the costs of rejecting the proposed measures or inaction?

Figure 1. Syria: Areas of Influence

Source: Areas of influence data from IHS Conflict Monitor, last revised January 3, 2017. All areas of influence approximate and subject to change. Other sources include UN OCHA, Esri and regional social media reports. Map created by CRS.

in order to promote a political settlement and reduce levels of violence? With Turkey, Jordan, and the Arab Gulf States? How might greater U.S. confrontation with Russia and/or Iran shape developments in Syria?These issues are discussed in more detail below (see "U.S. Policy and Assistance"). Select Proposed Syria-Related Legislation

S.Res. 116, Condemning the Assad regime for its continued use of chemical weapons against the Syrian people. Following the April 4, 2017, chemical weapons attack in Syria, several members of the Senate Foreign Relations Committee submitted a proposed resolution that, inter alia, would condemn Asad and Russia and call on the United Nations Security Council to take immediate, decisive action in response. The proposed resolution "reiterates that Bashar al-Assad has lost legitimacy as Syria's leader" and "insists that Bashar al-Assad must be held accountable for his war crimes and crimes against humanity."

H.R. 1923. Introduced April 5, 2017; would state that the President is prohibited from using members of the Armed Forces "to carry out offensive combat operations in Syria unless Congress has enacted a specific authorization for such use of members of the Armed Forces."

Caesar Syria Civilian Protection Act. In November 2016, the House passed H.R. 5732, known as the Caesar Syria Civilian Protection Act of 2016. The proposal, introduced by Representative Eliot Engel, would have required the President to impose specific sanctions on the Central Bank of Syria, as well as on foreign individuals who engage in financial, material, or technological support to the Syrian government, or provide material support to Syria's natural gas or petroleum production. These measures differ from current practice in that the imposition of sanctions is required, rather than left to the discretion of the President or dependent on an executive branch determination that an activity exists and an individual is involved. The act also would have expanded the definition of human rights abuses that require designations, and broadened the definitions of goods and technology transfer for which the President would have been required to impose sanctions. The act would have required the President to explain why particular named Syrian individuals had not been designated (several of those listed have been designated, since the list included senior government officials) and called for an assessment of the policy options to establish no-fly zones in Syria. The Senate did not consider the House-passed bill.

In March 2017, the bill was reintroduced as H.R. 1677, the Caesar Syria Civilian Protection Act of 2017. The bill contains a new section that would authorize capacity-building and transition assistance for Syria.

Preventing Destabilization of Iraq and Syria Act. In December 2016, Senators Marco Rubio and Robert Casey introduced S. 3536, known as the Preventing Destabilization of Iraq and Syria Act of 2016. The bill incorporated many aspects of H.R. 5732, including the requirement for the imposition of sanctions on the Central Bank of Syria as well as on foreign individuals that provide support for the Syrian government or for the maintenance or expansion of natural gas and petroleum production in Syria. In addition, it would have required the imposition of sanctions on Syrians complicit in the blocking of humanitarian aid. The bill also would have authorized the President to provide enhanced support for humanitarian activities in Syria, including the provision of food, shelter, water, health care, and medical supplies. It would have prohibited the President from imposing sanctions on a foreign financial institution for engaging in a transaction with the Central Bank of Syria for the sale of food, medicine, medical devices, donations intended to relieve human suffering, or nonlethal aid to the people of Syria. It further would have prohibited the President from imposing sanctions on internationally recognized humanitarian organizations for engaging in financial transactions related to the provision of humanitarian assistance, or for having incidental contact (in the course of providing humanitarian aid) with individuals under the control of foreign persons subject to sanctions under the act.

In January 2017, Senators Rubio and Casey reissued the bill as S. 138, known as the Preventing Destabilization of Iraq and Syria Act of 2017.

Stop Arming Terrorists Act. In January 2017, Representative Tulsi Gabbard introduced H.R. 608, known as the Stop Arming Terrorists Act. The bill would prohibit funds made available to any federal department or agency from being used to provide covered assistance to Al Qaeda and the Islamic State, or to any individual or group that is affiliated with, associated with, or cooperating with adherents of these groups. It would also prohibit direct or indirect covered assistance to countries that have provided assistance to Al Qaeda or the Islamic State, or to any individuals or groups affiliated with, associated with, or cooperating with adherents of these groups. Covered assistance is defined as defense articles, services, training, logistical support, or any other military assistance. It also includes intelligence sharing and cash assistance. The Director of National Intelligence (DNI) would make the initial determination of which groups have an affiliation or association with Al Qaeda and the Islamic State, and which countries provide assistance to those groups. In March 2017, Senator Rand Paul introduced the bill in the Senate as S. 532.

Conflict Synopsis

2011: Protests Emerge. In March 2011, protests broke out in the southern province of Dar'a. The unrest was sparked by the arrest of a group of school children, but reflected long-standing political and socioeconomic grievances. Largely peaceful protesters called for political and economic reforms rather than the removal of the Asad government. At the same time, a small armed element was also present within some of the protests. As security forces responded with mass arrests and occasionally opened fire on demonstrators, protests became larger and spread to other towns and provinces.

The opposition movement eventually coalesced into two umbrella groups—one political, one armed—and both based primarily in exile. Political groups merged to form the Syrian National Council (SNC), although members struggled to establish trust and develop shared goals. A small number of junior military defectors formed the Free Syrian Army (FSA), which claimed leadership over the armed opposition but whose authority was generally unrecognized by local armed groups. Ongoing violence, primarily but not exclusively on the part of the Syrian government, prompted President Obama in August 2011 to call for Syrian President Asad to step aside. Meanwhile Al Qaeda's affiliate in Iraq tasked some of its members to commence operations in Syria under the banner of a new group known as Jabhat al Nusra (aka the Nusra Front). In December 2011, the first Nusra Front suicide attacks hit government buildings in downtown Damascus.

2012: Insurgency. In 2012, the conflict became increasingly violent, as the government began to use artillery and fixed wing aircraft against opposition targets. Extremist attacks became more frequent—between November 2011 and December 2012, the Nusra Front claimed responsibility for nearly 600 attacks in Syria, ranging from more than 40 suicide attacks to small arms and improvised explosive device operations.¹18 In February 2012, the United States closed its embassy in Damascus, citing security concerns. Local armed groups began to seize pockets of territory around the country, primarily in rural areas. A July bombing in downtown Damascus killed several senior regime officials, including the then-Minister of Defense. Concerns about regime tactics became more acute, and President Obama in August declared that

We have been very clear to the Assad regime, but also to other players on the ground, that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized.... We have communicated in no uncertain terms with every player in the region that that's a red line for us and that there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons.²19

The international community also increased efforts to seek a negotiated solution to the conflict. In June, the United States and Russia signed the Geneva Communiqué, which called for the establishment of a transitional governing body with full executive powers.³20 The document, which became the basis of future negotiations between the government and the opposition, did not clarify the role of Asad in any future government. Meanwhile, Syria's political opposition remained divided and in flux. In November, the SNC became part of a larger umbrella group known as the National Coalition of Syrian Revolutionary and Opposition Forces (aka the Syrian Opposition Coalition, SOC), a move which some described as an effort to dilute the influence of Islamist members.

2013: Proxy War and Chemical Weapons. In March 2013, rebels seized the city of Raqqah, which became the first provincial capital to fall out of government control. A series of other opposition victories in the area led the government to effectively concede control of Syria's rural northeast to the opposition. At the same time, the Asad government received military and intelligence support from Iran and Lebanese Hezbollah, as well as political backing from Russia. In turn, the United States, Turkey, and some European and Arab Gulf states increased their support to the Syrian opposition—each prioritizing their own interests and at times working at cross purposes.

In April, the United Kingdom and France reported to the United Nations that there was evidence that the Syrian government had used chemical weapons (CW) on multiple occasions since December 2012.⁴21 In August, the United States attributed a large-scale CW attack on the Damascus suburb of Ghouta to the Syrian government.⁵22 President Obama requested congressional approval of a limited authorization for the use of military force to respond.⁶23 The following month, Russia negotiated an agreement for the Syrian government to dispose of its CW stockpiles and destroy associated facilities in exchange for staving off a U.S. military response.

2014: Caliphate and Operation Inherent Resolve. In February 2014, Al Qaeda formally disavowed the Islamic State because of the group's interference in Syria and its demands that the Nusra Front recognize IS leadership. After the Nusra Front and other opposition groups forced IS fighters from some areas of northwestern Syria, IS fighters seized vast stretches of territory in central and northeast Syria from local armed groups and in June declared the establishment of a caliphate spanning areas of both Syria and Iraq. Thousands of foreign fighters traveled to Syria and Iraq to join the Islamic State.

In August, the United States began air strikes in neighboring Iraq to stop the group's territorial advance and reduce the threat to U.S. personnel in Iraq. U.S. forces also airdropped humanitarian supplies to members of Iraq's Yazidi religious minority group trapped on Mount Sinjar. In September, the United States expanded air strikes to Syria, with the goal of preventing the Islamic State from using Syria as a base for its operations in Iraq. A subsequent air campaign to lift the IS siege on the Syrian Kurdish town of Kobane brought the United States into partnership with the Kurdish People's Protection Units (YPG), which U.S. officials have come to view as among the United States' most effective partners in the anti-IS campaign. In September 2014, Congress authorized the Administration to begin a train and equip program for select Syrian forces.⁷

24

2015: Train & Equip Begins, Russia Enters the Fray. In 2015, the Syrian government faced a number of additional territorial losses. Opposition forces captured the provincial capital of Idlib in northwestern Syria and surrounding areas with the support of Al Qaeda-linked fighters. Islamic State fighters seized territory in central Homs province, and Kurdish fighters expanded their control over areas along the Turkish border. In May, the United States began training the first batch of recruits for the Syria Train and Equip Program. The program was designed to build a local force capable of fighting the Islamic State, protecting opposition-held areas, and "promoting the conditions for a negotiated settlement to end the conflict in Syria."

Over the summer of 2015, Russia began a gradual buildup of Russian personnel, combat aircraft, and military equipment inside Syria, and began air strikes in September. The following month, the United States and Russia signed a memorandum of understanding to establish a safety-of-flight protocol for aircraft operating in the same airspace. Also in October, challenges in implementation led the Administration to modify the Syria Train and Equip program to focus on equipping existing units commanded by vetted leaders. Kurdish YPG forces that had received U.S. support in operations at Kobane merged with a small number of non-Kurdish groups to form the Syrian Democratic Forces (SDF), which began to receive U.S. support.

2016: Failed cessation of hostilities, regime retakes Aleppo. In 2016, the United States sought to step up diplomatic cooperation with Russia to achieve a reduction in violence. The two countriescountries twice attempted to implement a joint diplomatic initiative for a cessation of hostilities (CoH) between pro-government and opposition forces, yet both initiatives were widely considered unsuccessful. In contrast, the U.S.-led campaign against the Islamic State retook significant territory from the group, severing much of the group's access to the Turkish border—a key supply and foreign fighter transit route. However, the heavy participation of Syrian Kurdish fighters in counter-IS operations triggered Turkish opposition, and in August Turkish forces crossed the Syrian border into the town of Jarabulus, in an operation described by Turkish officials as aimed at neutralizing threats posed by both the Islamic State and Kurdish fighters. Meanwhile, Syrian and Russian forces—backed by Hezbollah, foreign Shia militias, and Iranian forces—increased the intensity of attacks on rebel-held eastern Aleppo, resulting in thousands of deaths. In December 2016, the Syrian government recaptured eastern Aleppo from opposition forces, and Russia and Turkey reached agreement on a proposed cease-fire to be followed by negotiations (see "The Russia/Turkey/Iran InitiativeAstana Process" below).

Russia's Military Intervention

Russian military involvement in Syria dates back to the 1950s. Soviet and Russian Federation naval forces have accessed a facility at the Syrian port of Tartus since the early 1970s, using it as a logistical hub to enable longer Mediterranean operations. Syria eventually became the largest Middle East recipient of Russian equipment and training. While Russian personnel have since been based in Syria to maintain Russia military equipment and train Syrians, their numbers have fluctuated over time.

With the onset of unrest in 2011, Russia provided sustained political, economic, and military support to the Syrian government. Russian diplomats blocked action in the U.N. Security Council that would have increased pressure on the Asad regime for its conduct. In 2012, Russia began printing Syrian banknotes after European sanctions prevented Syria's currency from being printed in Austria. After the chemical attacks outside Damascus in 2013, Russia negotiated an agreement whereby the Syrian government relinquished its chemical weapons, avoiding proposed U.S. military strikes. Throughout the conflict, Russia has continued to resupply Syrian military forces, although Russian officials have stated that they are merely fulfilling existing bilateral contracts.

Over the summer of 2015, Russia began a gradual buildup of personnel, combat aircraft, and military equipment inside Syria. In September of that year, Russian forces began air strikes inside Syria, initially focused on opposition targets—including some groups reportedly backed by the United States.⁸25 In 2016, Russia expanded its targeting to include Islamic State forces, although it continued to occasionally target U.S.-backed rebel groups.⁹26

The series of losses suffered by Syrian government forces in 2015 may have contributed to Russia's decision to enter the conflict directly when it did. Russian concerns about U.S. and other third-party security assistance to Syrian opposition groups, and the potential for broader U.S.-led coalition military operations in Syria, also may have been motivating factors. Russia remains an outspoken critic of what it describes as unwarranted external interference aimed at regime change in Syria and elsewhere.

Russian ground forces in Syria have not played a significant combat role and appear to be focused primarily on defending Russian bases and installations in Syria—although some are likely embedded as advisors with Syrian military forces. To date, air strikes have constituted Russia's primary military effort in Syria. These strikes have enabled pro-Asad forces to reverse some opposition gains, particularly around Aleppo. Russia's introduction of advanced air defense systems in Syria (reportedly including the S-300 and S-400) constrains the ability of other aircraft to operate freely in the area—complicating proposals calling for the establishment of a no-fly zone. At the same time, Russia has pushed for cooperation between U.S. and Russian military forces in Syria against terrorist groups—which in Russia's view includes any group fighting the Asad government. Reports have periodically suggested that Russia plans to withdraw some military forces from Syria, but as of January 2017, available evidence suggests Russian military personnel remain present and active in the country.

Recent Developments

Military

Aleppo

In December 2016, Syrian and pro-government forces retook rebel-held eastern Aleppo after opposition fighters evacuated their remaining positions. Aleppo, Syria's most populous city, had been divided into western (regime-held) and eastern (opposition-held) sectors since 2012. After four years of fighting, Syrian forces were able to encircle opposition-held areas of the city in July 2016, with the assistance of Iraqi militias, Lebanese Hezbollah, and Iranian ground forces. Following the collapse of the September 2016 cessation of hostilities agreement, Syrian military and pro-government forces began a ground assault into eastern Aleppo, backed by an intense aerial bombardment by Syrian and Russian forces.¹⁰ U.S. And European officials accused Russia of using bunker-buster bombs and incendiary munitions against civilians in the city.¹¹ Russia denied targeting civilians. U.S. Permanent Representative to the United Nations Ambassador Samantha Power described the actions of the Syrian government and Russian forces in Aleppo as "an all-out air and ground offensive" that was "apocalyptic" in nature.¹²

In December, rebels in eastern Aleppo agreed to a cease-fire in order to evacuate their members from the city. Evacuations of civilians and fighters began under terms negotiated by Russia (on behalf of pro-regime forces) and Turkey (on behalf of the opposition). Several thousand people were evacuated from eastern Aleppo to nearby Idlib province in northwestern Syria, facilitated by the Syrian Arab Red Crescent and the International Committee of the Red Cross. Iran reportedly halted the evacuation of eastern Aleppo until armed groups allowed the simultaneous evacuation of Foua and Kefraya, two pro-government Shia villages in Idlib province that had been besieged by rebels since 2015.¹³

Figure 2. Syria-Turkey Border: Contested Territorial Areas

Source: Areas of influence based on data from IHS Conflict Monitor, and adapted by CRS based on media accounts. Other sources include UN OCHA and Esri. Notes: All areas approximate. Areas of influence subject to change.

Turkey and Operation Euphrates Shield¹⁴

In August 2016, U.S. and Turkish aircraft supported an incursion by Turkish special forces and armored vehicles into the Syrian border town of Jarabulus. The operation, which also involved some Syrian rebels, was nominally intended to clear Jarabulus of IS fighters. However, a Turkish presidential spokesman stated that the operation was aimed at neutralizing threats that Turkey perceives from both the Islamic State and the YPG,¹⁵ which had advanced northward toward Jarabulus after clearing the city of Manbij. Turkey has previously expressed concern that the YPG could create a contiguous area of Kurdish control along the Turkish border by unifying its eastern and western cantons (shaded yellow in Figure 2). Kurdish forces—predominantly YPG fighters—already control the majority of the Syrian border to the east of the Euphrates river. Turkey considers the YPG to be the Syrian arm of the Kurdistan Workers Party (PKK), which both Turkey and the United States have designated as a terrorist group. The United States does not view the YPG as a terrorist organization, though there is some evidence to support Turkish claims of ties between the two groups.¹⁶

After dislodging IS fighters from the town of Jarabulus and elsewhere along the border between the Kurdish cantons (in some cases via largely uncontested efforts), Turkish-supported forces have clashed with Kurdish-led units in the area, and Turkish air strikes have targeted Kurdish-controlled positions. Turkey claims that these strikes have killed hundreds of YPG personnel. As of December 2016, Turkish-supported forces appeared focused on obtaining control of Al Bab, a key transport hub that has been controlled since 2014 by the Islamic State and is coveted by all parties involved in the ongoing conflict in northern Syria.¹⁷

U.S. forces have provided air, artillery, and special forces support to Turkish-supported forces in their operations against the Islamic State (with the joint effort dubbed "Operation Noble Lance" since September 2016),¹⁸ but U.S. officials have called upon the Turkish-supported forces and the Kurdish-led forces to refrain from fighting one another. The embedding of U.S. forces on both sides could be a way to keep communications open between the two and try to reduce the possibility of armed conflict.¹⁹ However, a spokesperson for Combined Joint Task Force (CJTF)-OIR stated in mid-November 2016 that U.S. forces were not providing air strikes in support of Turkish operations focused on Al Bab, and that embedded U.S. forces had been decoupled from Turkish-supported forces when they began advancing on Al Bab.²⁰ He said that Turkey was pursuing these operations "independently and what we'd like to do is continue to work with them to develop a plan where everyone remains focused on Daesh."²¹

Turkey has engaged with Russia in pursuit of a renewed cease-fire and negotiation initiative since December 2016.

For additional background, see CRS Report R41368, Turkey: Background and U.S. Relations, by [author name scrubbed] and [author name scrubbed], and CRS Report R44513, Kurds in Iraq and Syria: U.S. Partners Against the Islamic State, coordinated by [author name scrubbed].

SDF Operations to Isolate Raqqah

In November 2016, Syrian Democratic Forces (SDF) began a campaign to isolate Raqqah city, the self-declared capital of the Islamic State. Lieutenant General Stephen Townsend, Commander of OIR, said that operations focused on Raqqah are urgent largely because of the coalition's interest in preventing IS fighters (including those fleeing Mosul) from regrouping in Raqqah and carrying out potential external attacks.²² Brett McGurk, the Special Presidential Envoy to the Global Coalition to Counter ISIL, stated that U.S. Special Forces would assist as advisors in the operation (dubbed "Euphrates Rage").²³ In a November 10 Defense Department briefing, the OIR spokesperson indicated that U.S. forces in the region were providing air support to the SDF—including both YPG and Arab fighters (the Arabs within the SDF are sometimes known as the "Syrian Arab Coalition")—as part of the operations to isolate Raqqah.

Operations within Raqqah itself are anticipated to follow, although U.S. military leaders have said that the isolation phase could take "months."²⁴ Responding to threats they face in Mosul and Raqqah, as of December 2016, some IS fighters are reportedly relocating to the Syrian province of Deir ez Zor near the Iraqi border.²⁵

On December 10, Defense Secretary Carter announced that the "force management level" for U.S. personnel in Syria would be increased to potentially allow the deployment of up to 500 individuals, including special operations forces trainers, advisors, and explosive ordnance disposal teams.²⁶ U.S. officials have not confirmed the current number of U.S. special operations forces already present in Syria.

Political

Failure of Cessations of Hostilities in 2016

In February 2016, the United States and Russia negotiated a cessation of hostilities (CoH) between pro-government and opposition forces, and agreed to use their respective influence with the warring sides to implement the agreement. The CoH excluded the Islamic State and the Nusra Front (now known as Jabhat Fatah al Sham/the Levant Conquest Front), which remained legitimate targets for attack by all parties. The CoH was widely violated by all sides and was criticized for lacking enforcement and accountability mechanisms.

In September 2016, Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov announced a new agreement designed to reduce violence and resume progress toward a political settlement. The agreement came into effect on September 12 and called for seven consecutive days of reduced violence and unrestricted humanitarian access to besieged areas, after which the United States and Russia would establish a Joint Implementation Center (JIC) to target the Islamic State and the Nusra Front. Such cooperation would be predicated on Russia's ability to prevent Syrian government forces from conducting air strikes on opposition-controlled areas. Kerry also stated that U.S.-backed opposition groups would need to distance themselves from the Nusra font in order to preserve their legitimacy.²⁷ The full text of the agreement was released by the Associated Press in late September.²⁸

While the agreement resulted in a brief reduction in violence, the United Nations stated that the Syrian government had not allowed full humanitarian access. A series of military strikes also escalated tensions between the two sides. On September 17, U.S. and coalition forces inadvertently struck what appeared to be Syrian military forces during an operation against the Islamic State. On September 19, a convoy of aid directed by the Syrian Arab Red Crescent (SARC) was destroyed, apparently by air strikes that the United States government attributed to Russian forces. Approximately 20 civilians and 1 SARC staff member were killed.²⁹

In late September, Syrian and Russian forces launched a major aerial assault on opposition-held areas of eastern Aleppo.³⁰ In response to the continued offensive, the United States suspended bilateral talks with Russia on Syria in early October. U.S. officials stated that the United States would continue to pursue efforts to reach a cease-fire via multilateral negotiations with Russian officials, and would continue de-confliction with Russia on military operations.³¹

Prospects for Peace Negotiations

Since 2012, the Syrian government and opposition have participated in U.N.-brokered negotiations under the framework of the Geneva Communiqué. Endorsed by both the United States and Russia, the Geneva Communiqué calls for the establishment of a transitional governing body with full executive powers. According to the document, such a government "could include members of the present government and the opposition and other groups and shall be formed on the basis of mutual consent."³² The document does not discuss the future of Asad.

Subsequent negotiations have made little progress, as both sides have adopted differing interpretations of the agreement. The opposition has said that any transitional government must exclude Asad. The Syrian government maintains that Asad was reelected (by referendum) in 2014,³³ and notes that the Geneva Communiqué does not explicitly require him to step down. In the Syrian government's view, a transitional government can be achieved by simply expanding the existing government to include members of the opposition. Asad has also stated that a political transition cannot occur until "terrorism" has been defeated.

In late 2015, Syria's various international backers met in Vienna, resulting in the dissemination of two documents: the Vienna Communiqué on Syria (issued October 30)³⁴ and the Statement of the International Syria Support Group of November 14, 2015.³⁵ Referred to collectively as the "Vienna Statements," they affirmed the unity, independence, territorial integrity, and secular character of Syria. They stated that Syria's state institutions would remain intact, and that the rights of all ethnic and religious minorities would be protected. Reaffirming their commitment to a political transition based on the Geneva Communiqué, they called for a new constitution and elections. They also set a target date of January 1, 2016, for the resumption of formal negotiations between the government and the opposition, and called upon the Syrian opposition to select negotiating representatives. The opposition did so during a December 2015 meeting in Riyadh, which established the opposition High Negotiations Committee (HNC).³⁶

In addition, the Vienna Statements expressed support for a Syrian-led political process that would, "within a target date of six months, establish credible, inclusive, and nonsectarian governance and set a schedule and process for drafting a new constitution. Free and fair elections would be held pursuant to the new constitution within 18 months." On December 18, the U.N. Security Council unanimously passed UNSCR 2254, which endorsed the Vienna Statements.³⁷

In January 2016, the HNC participated in indirect talks with the Syrian government, but these soon dissolved amid ongoing government violence. The last round of U.N.-brokered peace negotiations between the Syrian government and members of the opposition closed in April 2016 without achieving significant results. In September 2016, the HNC put forward its own plan for a political transition. Similar to other proposals, the HNC plan calls for a cease-fire accompanied by negotiations, which would result in a transitional governing body and finally elections. The primary difference in the HNC plan appears to be that it requires Asad's departure within a defined time frame.

The Russia/Turkey/Iran Initiative

In December 2016, the foreign and defense ministers of Russia, Iran, and Turkey met in Moscow to discuss a political resolution to the Syrian conflict. The parties issued a joint statement, which laid out a set of principles for a future peace deal. While acknowledging that the United States was not asked to participate in the talks, a State Department spokesperson characterized the joint statement as "borrowing […] from ideas that the United States has led and pushed from the outset."³⁸ On December 29, Russia and Turkey announced a new cease-fire agreement to be followed by peace talks in Kazakhstan within a month, cosponsored by both countries.³⁹ On December 31, the U.N. Security Council unanimously adopted Resolution 2236, welcoming and supporting the Russian-Turkish initiative. As of early 2017, the cease-fire was largely holding in northern Syria but rebels and government forces continued to clash in the Damascus suburbs, amid water shortages in the capital.⁴⁰

Humanitarian Situation⁴¹

Violence, insecurity, government and opposition interference, the closure of key border points, bureaucratic procedures, and resource shortfalls continued to hinder aid delivery, particularly to an estimated 4.9 million people in besieged and hard-to-reach areas.⁴² In addition to the situation unfolding in Aleppo, these included areas controlled by government forces or under opposition control and eastern provinces under Islamic State control.⁴³

During the Syria conflict, systematic violations of human rights and international humanitarian law (IHL) have been widespread by all parties, including the Islamic State.⁴⁴ Civilian protection concerns include mass executions, systematic rape and sexual violence, torture, and appalling treatment of those in detention. Lack of access, food insecurity, health concerns (injuries, disease outbreaks, serious medical conditions and disabilities), inadequate shelter, and an economic recession coupled with growing poverty contribute to the vulnerability of millions of civilians.

As of December 2016, an estimated 13.5 million people inside Syria, more than half the population, were in need of humanitarian and protection assistance, including 6 million children.⁴⁵ There were estimated to be more than 6.3 million Internally Displaced Persons (IDPs), but this number is imprecise and very fluid. Many Syrians, some of whom have been displaced multiple times within the country, leave their homes to escape violence and then return when conflict in their area decreases. It is not clear how many IDPs are affected by repeat displacements, nor if, or how often, they are included in IDP counts. It is further estimated that as of December 2016, 7 million people in Syria were food insecure and 12.8 million people were in need of health assistance.⁴⁶

In addition, more than 4.8 million Syrians have registered as refugees abroad, with most fleeing to countries in the immediate surrounding region as well as Europe.⁴⁷ Experts recognize that some fleeing Syrians have not registered as refugees and have chosen instead to blend in with the local population, living in rented accommodations and makeshift shelters, particularly in towns and cities. The U.N. Office for the Coordination of Humanitarian Affairs (UNOCHA) estimates that more than 90% of Syrian refugees are living outside camps in mostly urban settings, where refugees may be difficult to identify and assist. Interagency cross-line convoys and cross-border operations from Turkey and Jordan provided humanitarian assistance and protection services to millions of people across the country each month.⁴⁸

In December 2015, the United Nations, along with humanitarian partners, launched several appeals: the Syria Regional Refugee and Resilience Plan (3RP) appeal for $4.6 billion; and the Humanitarian Response Plan (HRP) for Syria for $3.1 billion.⁴⁹ Since 2011, U.N. appeals have remained significantly underfunded, which in 2015 resulted in cuts to food aid and cash assistance. As of December 2016, the 2016 appeal for Syria was 45% funded. (At a February 2016 pledging conference in London, donors pledged $11.3 billion for the Syria crisis, of which $5.9 billion was for 2016 and $5.4 billion for 2017-2020.)

The United States is the largest donor of humanitarian assistance to the Syria crisis. Since FY2012, it has allocated more than $5.9 billion to meet humanitarian needs using existing funding from global humanitarian accounts and some reprogrammed funding.⁵⁰

U.S. Policy and Assistance

U.S. Strategy and Policy

After initially calling for Bashar al Asad to step down, the Obama Administration actively engaged since 2012 in multilateral efforts to reach a negotiated settlement between the Asad government and many of the opposition groups arrayed against it. This approach was combined with nonlethal U.S. support to select opposition groups, reported covert assistance to some armed groups, overt training and assistance to vetted Syrian opposition forces for select purposes, and the often-stated assertion by Administration officials that "there is no military solution to the conflict." This assertion has appeared to reflect the Obama Administration's stated preference for some preservation of elements of the Syrian state apparatus over military developments that lead to state collapse.

Changes in battlefield dynamics over time—particularly the rise and success of the Islamic State organization and other Salafist-jihadist insurgent groups, the weakening of pro-Asad forces, and Russia's military intervention—were accompanied by some shifts in U.S. policy and rhetoric about the conflict. While continuing to refer to a negotiated settlement as the aim of U.S. policy and stating that Asad has lost legitimacy, the Obama Administration in mid-2014 publicly embraced limited overt intervention in the conflict in Syria. It requested and received congressional authority and funding for the training and equipping of vetted Syrians to counter terrorism and to contribute to conditions intended to lead to a negotiated settlement of the conflict. It also launched U.S. military operations against Islamic State and other extremist targets, and these operations have undermined extremist control in some areas of the country.

In 2015, Secretary of Defense Carter described the "best" scenario for the Syrian people as one that would entail an agreed or managed removal of Asad and the coalescence of opposition forces with elements of the remaining Syrian state apparatus as U.S. partners in opposition to the Islamic State and other extremists.⁵¹ In July 2015, Secretary Carter told the Senate Armed Services Committee that

the outcome that we are aiming for is one in which Bashar al Asad and those who have been associated with his atrocities in Syria are removed and -- but the structures of government in Damascus and in Iraq [sic] that remain continue on our -- in an inclusively governed way that is multisectarian to get -- to include Alawites and others and that can then turn to the task of regaining its sovereign territory from ISIL to the east in a project that would look like what we are working with Baghdad to accomplish to its west in Iraq. That is the post-Asad transition that will be the best for the Syrian people and the best for our counter-ISIL strategy.⁵²

Secretary Carter also warned that "further conflict, further civil war, and ethnic cleansing" could follow in a scenario in which the Asad regime collapsed, making a political transition "much to be preferred."⁵³

From late 2015 onward, U.S. policy reflected the Obama Administration's desire to bring an end to the wider conflict while promoting multilateral cooperation against select groups, where possible. Developments that may have shaped evolution in U.S. policy include Russia's 2015 military intervention, the corresponding shift by pro-Asad forces from defense to offense in some areas, the weakening of the Islamic State, and shared U.S.-Russian concerns about the strength of other extremist groups. Obama Administration officials and Members of Congress have expressed confidence about the course of the campaign against the Islamic State, but debate continues about measures that could place greater economic or military pressure on the Asad government or provide more or different levels of support to various U.S. partner forces. As of January 2017, the policies of President-elect Donald Trump and his Administration have yet to be fully determined and articulated.

Viability of the Syrian State

Whether or not state preservation scenarios described as desirable by U.S. officials to date are feasible in the longer term is debatable. While U.S. officials and their counterparts in other governments may prefer that some element of Syria's state apparatus and security services to be salvageable as a hedge against total state collapse, the true capacity and durability of Syria's state institutions is largely unknown. Some analysts doubt that the Syrian government has the capacity to independently defend and administer areas under its current control, much less reassert its sovereign control and administrative authority over areas of the country that have slipped from its grasp. Many armed and unarmed opposition groups have called for the removal and prosecution of all officials with "blood on their hands," including Asad, while calling for the preservation and reform of key security institutions. Others seek more fundamental change and have made hostile sectarian statements about the collective culpability of Syrian Alawites for the Asad government's conduct during the war.

Even if a transitional Syrian state acceptable to a sufficient segment of armed opposition forces were achieved, it may not prove to be capable of administering state services, dedicated to impartially providing justice according to the rule of law, or willing to partner with the United States and others against extremist groups. It is furthermore unclear whether the balance of power, in such a scenario, would lie with nonextremist opposition forces and the remnants of the Syrian state, even if somehow they were induced to work together. The prospect of Syria's dissolution into smaller de facto jurisdictions might allow for deeper U.S. partnership with individual groups or regions but might also provoke strong, self-interested, and disparate reactions from Syria's neighbors and outsiders like Iran and Russia. A more likely scenario than either a formal division of the country or reunification under moderate opposition forces may be one in which a de facto division of Syria prevails and the United States, its partners, and its adversaries must manage the negative consequences of an ambiguous, lasting conflict that is beyond their ability to resolve.

Proposals for a Safe Zone

Some Syrian opposition figures, foreign governments, independent observers, and Members of Congress have proposed the establishment of "safe zones" in parts of Syria under opposition control for humanitarian protection among other various purposes. Such proposals vary in their specificity and scope, and supporters and critics make a range of arguments concerning their relative feasibility, cost, likelihood of success, risks, and potential rewards.

Obama Administration officials cited a number of reasons for their reluctance to intervene militarily in Syria's conflict. In congressional testimony in February 2016, Secretary of State John Kerry stated "our Pentagon estimates that to have a true safe zone in the north of the country you may have upwards of fifteen to thirty thousand troops. Now are we ready to authorize that? Are we ready to put them on the ground?"⁵⁴ In 2015, Secretary of Defense Ashton Carter described the establishment of a safe zone as a "major combat mission," noting that such a zone would likely be contested by both Syrian government forces and extremist groups, and would not necessarily receive strong military support from neighboring states.⁵⁵

In a December 2016 press conference, President Obama described the reasoning behind his Administration's decision to limit U.S. military involvement in Syria:

the challenge was that, short of putting large numbers of U.S. troops on the ground, uninvited, without any international law mandate, without sufficient support from Congress, at a time when we still had troops in Afghanistan and we still had troops in Iraq, and we had just gone through over a decade of war and spent trillions of dollars, and when the opposition on the ground was not cohesive enough to necessarily govern a country, and you had a military superpower in Russia prepared to do whatever it took to keeps its client-state involved, and you had a regional military power in Iran that saw their own vital strategic interests at stake and were willing to send in as many of their people or proxies to support the regime -- that in that circumstance, unless we were all in and willing to take over Syria, we were going to have problems [...]⁵⁶

As noted above, international legal considerations also factored into the Obama Administration's decisionmaking regarding the establishment of a safe zone inside Syria. The United Nations Security Council has authorized the provision of cross-border assistance without the Syrian government's permission, but it has not authorized the use of military force by third parties or "all necessary means" to ensure the protection of civilians or the delivery of humanitarian assistance.

Nevertheless, critics of the Obama Administration's approach argue that the limited nature of U.S. intervention to date has contributed to the rise of the Islamic State, failed to adequately support now-faltering moderate opposition elements, and prolonged the suffering of Syrian civilians. Some critics also contend that the image and influence of the United States have been weakened by a refusal to intervene to protect civilians or to forcefully respond to provocations by Asad or extremist forces.

Congressional Debate

To date, Members of Congress have not reached a degree of consensus on the Syrian conflict that would allow Congress to offer its own detailed plan for responding to Russia's intervention, bringing the crisis to a close, supporting a political transition and reconstruction, or combatting the Islamic State and other extremists in Syria. Congress acted to provide the Obama Administration with new authorities and contingency funds to address the Syrian conflict, but placed limits on newly authorized efforts and required the executive branch to use contingency authorities and funds to provide nonlethal support to armed opposition groups outside of the specially authorized Train and Equip program. Congress debated but did not grant President Obama authority to use military force in response to the Asad government's alleged use of chemical weapons in August 2013. Congress has yet to grant specific authorization for the use of military force against the Islamic State or new and specific authorization for the use of military force to defend U.S.-backed Syrian opposition forces from attacks by pro-Asad forces.

Over time, some voices in Congress have called for different forms of U.S. military intervention to protect civilians in select areas of the country or to weaken extremist groups. Some also favor an expansion of U.S. training and equipping of moderate opposition groups. Others in Congress have warned against the possible unintended consequences of deeper U.S. involvement. However, Congress also has not reached consensus on whether or how any reduction in involvement by the United States and its allies might better manage the negative consequences of the ongoing conflict.

FY2017 Budget Requests for Syria

The FY2017 foreign assistance request for Syria reflected the two main elements of the Obama Administration's policy response: (1) humanitarian assistance to meet the needs of internally displaced Syrians and refugees in neighboring countries, and (2) continued political, economic, and nonlethal military support for national and local opposition groups. In addition to more than $238 million in foreign assistance funded programs, the Obama Administration requested $250 million in FY2017 defense funding to continue the Train and Equip program for vetted Syrians authorized by Congress in 2014.

The Administration's FY2017 request of more than $4 billion for Syria-Iraq-Islamic State-related funding did not draw clear distinctions in purpose between funds intended for enduring programs, funds to counter the Islamic State specifically, funds to respond to the crises in Syria and Iraq, and funds for related humanitarian responses. Funding requests were presented as mutually reinforcing. The request called for $238.5 million to support U.S. efforts to achieve a political solution in Syria and counter the Islamic State and other extremist threats, including $50 million in the Peacekeeping Operations account to provide nonlethal assistance to moderate, armed Syrian opposition groups.

The Administration also described enduring foreign assistance programs for Jordan ($1 billion) and Lebanon ($234 million) as contributions toward the overall U.S. effort against the Islamic State and a response to the Syria crisis. Assistance to these countries would address not only the security challenges, but also economic and humanitarian needs of communities hosting Syrian refugees.

Combatting the Islamic State in Syria

President Obama said in September 2014 that U.S. engagement in Syria would remain focused "narrowly" on helping Syrians combat the Islamic State, while continuing "to look for opportunities" to support a political resolution to Syria's conflict.⁵⁷ As discussed above, U.S. and coalition air strikes continue to target IS forces in some areas of Syria, which have assisted anti-IS forces in retaking some territory. The United States also provides assistance to a range of anti-IS forces, including Kurdish and non-Kurdish members of the Syrian Democratic Forces (SDF) coalition and individuals from eastern Syria based near At-Tanf. In parallel, U.S. diplomatic officials have sought to more closely link the campaign against the Islamic State and other extremists to efforts to find a solution to the broader conflict.

Previously, the Obama Administration had reiterated its view that any effort to defeat the Islamic State in Syria must be complemented by an effort to bring an end to the broader Syrian conflict that would result in a transition away from Bashar al Asad's rule. President Obama and senior U.S. officials identified Asad's presence as an aggravating factor and a contributor to the appeal of extremist groups—a view rejected by Russian and Syrian officials. However, increased U.S. dialogue with Russia about potential counterterrorism cooperation led some observers to question whether U.S. commitment to Asad's immediate departure has waned. Combatants in the Syrian war and the broader international community are awaiting the formal articulation of President-elect Trump's views on this question.

To date, challenges to the U.S. counter-IS campaign in Syria have included:

Finding effective partners. Some U.S. critics of the Obama Administration's approach to the conflict and terrorism threats in Syria have argued that U.S. strategy has lacked effective Syrian partners willing or able to advance against Islamic State- and/or Al Qaeda-affiliate-held territory on the ground or to durably administer recaptured areas once extremists are defeated.⁵⁸ The former concerns have been addressed to a certain degree by the evident military success of some U.S. partner forces in operations against the Islamic State, but the latter concerns about long-term administration and political repercussions remain. This is particularly true with regard to U.S.-backed Kurdish forces in Syria, whose military successes have raised concerns among other U.S. partners, principally the Turkish government. At times, various U.S. critics have suggested that the United States should either abandon its efforts to support vetted partner forces in Syria or drastically expand the size and scope of those efforts to create more formidable or inclusive partner forces.

Partner expectations. Syrian opposition forces who have been fighting the Islamic State welcome U.S. and coalition assistance in their campaign, but question why the United States does not take military action against the Asad government or take more robust direct action to degrade IS capabilities in Syria. Some Syrian political and military opposition forces appear to resent what they see as the United States' narrow focus on fighting Sunni extremists in Syria and some have indicated that they may insist on broader support for their anti-Asad goals as a condition of working with the U.S.-backed coalition against the Islamic State.⁵⁹ These parties also question why the United States and coalition partners are willing to act militarily to halt Islamic State atrocities but not to protect Syrian civilians from attacks by government forces or opposition groups.

U.S. Obligations to Partners. Senior Obama Administration officials told Congress and the press that the Administration was prepared to provide military protection to U.S.-trained Syrian participants of the Train and Equip program in their engagements with Islamic State forces and if they came under attack by other forces, including the Syrian government.⁶⁰ In the case of potential attack by Syrian government forces, for example, such protection could entail attacks against Syrian military units, now backed by Iran and Russia. However, DOD-equipped forces have focused on the Islamic State and avoided engagement with the Syrian military. In response to a question on whether the U.S.-backed SDF in northern Syria could eventually clash with Syrian government forces near the IS capital of Raqqah, U.S. military officials stated that U.S.-backed forces in northern Syria "know that the engagement they have with the United States, with the coalition, is specific to the fight against ISIL."⁶¹

U.S.-trained or -equipped units have come under attack by the Nusra Front, the Islamic State, the Turkish military, the Syrian military, and the Russian air force.⁶² The United States responded with air strikes to counter IS and Nusra Front attacks, and has sought to dissuade further attacks by other states' forces.⁶³

Managing disputes. U.S. assistance to the Kurdish YPG continues to be a significant point of contention with Turkey, which considers the YPG to be a terrorist group. The United States has tried to ameliorate these concerns by bolstering the presence of Sunni Arabs within the U.S.-supported Syrian Defense Forces, a primarily Kurdish force. In addition, there have also been reports about fighting between different Syrian rebel groups supported by the United States.⁶⁴

End User Issues. Material assistance provided by the United States to Syrian rebels could potentially fall into the hands of extremist groups or the Asad government. Since the start of the DOD-administered Syria Train and Equip Program, there have been several reports of U.S.-provided weaponry falling into the hands of the Nusra Front or the Islamic State.⁶⁵ There has also been at least one report of U.S. weapons being diverted by regional allies.⁶⁶

For information on the operational aspects of U.S. operations against the Islamic State in Syria and Iraq, see CRS Report R43612, The Islamic State and U.S. Policy, by [author name scrubbed] and [author name scrubbed].

SDF Operations to Isolate Raqqah

On November 6, 2016, the SDF began the first stage of a campaign (dubbed "Euphrates Wrath") to isolate Raqqah city, the self-declared capital of the Islamic State. Lieutenant General Stephen Townsend, Commander of OIR, said that the operation was urgent largely because of the coalition's interest in preventing IS fighters (including those fleeing Mosul) from regrouping in Raqqah and carrying out potential external attacks.²⁷

Participants. The SDF has led the operation to isolate Raqqah city. Established in late 2015 as an umbrella group made up largely of Kurdish fighters, the SDF has adjusted its forces over time to more closely reflect the demographics in its areas of operation. In March 2017, General Townsend stated that the SDF was 40% Kurdish YPG forces, and 60% Syrian Arab Coalition.²⁸ The Syrian Arab Coalition (SAC) is a term used by U.S. military officials to describe ethnic Arab elements of the SDF. There are few publicly available details on which individual groups constitute the SAC.²⁹ U.S. officials and other observers acknowledge that the YPG continues to play a leading role in SDF operations.³⁰

U.S. Role. The United States provides wide-ranging support to SDF operations against the Islamic State in Raqqah. The United States has provided air support to the SDF since the onset of Euphrates Wrath,³¹ as well as small arms, ammunition, supplies, and equipment. U.S. officials have stated that weapons have been provided only to the non-Kurdish elements within the SDF,³² though reports indicate that U.S. officials have contemplated directly arming the YPG.³³ The United States has also trained Arab forces within the SDF. In early March, General Townsend estimated that the United States had provided training for roughly 4,000 Arab forces.³⁴

Some U.S. troops have been colocated with SDF forces in Raqqah since late 2015. A small contingent of 50 U.S. Special Forces initially deployed to northern Syria in October 2015 to support operations against the Islamic State. In April 2016, their numbers were increased by 250. On December 10, then-Defense Secretary Carter announced that the force management level (FML) for U.S. personnel in Syria would be increased to potentially allow the deployment of up to 500 individuals, including special operations forces trainers, advisors, and explosive ordnance disposal teams.³⁵

In March 2017, roughly 300 members of the 11^th Marine Expeditionary Unit deployed to Syria to assist SDF operations in Raqqah; an additional 100 Army Ranger forces deployed to the city of Manbij in Aleppo province.³⁶ Although the FML caps the number of U.S. forces in Syria at 503, a U.S. military spokesperson stated that the deployment of the Marines to Raqqah was an example of the ability of coalition leaders to "bring in capabilities on a temporary basis to meet specific objectives."³⁷ The Marines have provided heavy artillery support to SDF operations, such as the successful operation in late March to seize Tabqa airfield.³⁸

Figure 2. Raqqah Operations

As of April 4, 2017

Source: Areas of influence based on April 4, 2017, data from IHS Conflict Monitor, and adapted by CRS based on media accounts.

Progress to Date. On December 10, 2016, the SDF announced the second phase of Euphrates Wrath. In late 2016, some IS fighters reportedly relocated to the Syrian province of Dayr az Zawr near the Iraqi border, in response to coalition pressure around Mosul and Raqqah.³⁹ On February 4, 2017, the SDF announced the third phase of the operation, which has reportedly focused on severing the main ground line of communication between the cities of Raqqah and Dayr az Zawr. In late March, U.S. military leaders reported that the SDF had completely isolated the area to the east of Raqqah and were working to seize both the Tabqa Dam and the city of Tabqa, located to the west of Raqqah.⁴⁰ According to a U.S. military spokesperson, "seizing Tabqa dam will isolate Raqqa from three sides and give the SDF a strategic advantage and the launching point they need to liberate the city."⁴¹

Unresolved Issues. As SDF forces continue operations in Raqqah province, there is ongoing debate regarding a number of operational and policy questions, including:

• Which forces will participate in the fighting inside Raqqah city? The United States has relied on SDF forces thus far, which contain a significant Kurdish contingent. Turkey opposes the participation of Kurdish fighters in the battle for Raqqah city, and has reportedly proposed that Turkish forces assume this role instead. In congressional testimony, CENTCOM Commander General Votel acknowledged the difficulty in working with "an indigenous force that [has] tensions with a NATO ally."⁴² Following a March meeting between the military chiefs of staff of the United States, Turkey, and Russia, Turkish Prime Minister Binali Yildirim remarked, "it appears that the U.S. may carry out this operation with the YPG, not with Turkey.... If this operation is carried out in this manner, there will be a cost for Turkey-U.S. relations."⁴³
• Should the United States provide additional weapons to the SDF? While U.S. officials have described the SDF as "the most effective ground force against ISIS in Syria,"⁴⁴ it is not clear that the group currently has the resources it needs for an operation to retake Raqqah city. In March 2017, General Townsend stated, "we're still in decision-making stages as to whether or not we will assault Raqqa with the SDF and what equipment they might need.… [T]he Syrian Democratic Forces are an irregular light infantry force mounted mostly in pickup trucks. So, they have very few heavy weapons."
• Should the United States arm the Kurds directly? U.S. officials have stated that they do not provide weapons directly to Kurdish groups, but rather to the Arab groups that fight alongside them under the SDF umbrella. Turkey has reportedly expressed concern that any weapons given to Syrian Kurdish groups could be used against Turkey.⁴⁵ At the same time, U.S. military officials have stated that arming Syrian Kurds could increase the effectiveness of the anti-IS campaign, particularly in Raqqah.
• Who will govern Raqqah after anti-IS operations are complete? While Kurdish and non-Kurdish elements of the SDF may have a part in the seizure of Raqqah from the Islamic State, General Townsend has said, "I think at the end of the fight, there are probably few, if any, probably none—Kurdish fighting elements left in Raqqa, because that's not the demographics of the place. They'll turn it over to Raqqawis to secure and govern themselves."⁴⁶ It is unclear to what extent local forces will be able to secure Raqqah without a residual YPG presence, partly due to questions about the ability of non-Kurdish SDF elements to secure smaller areas previously seized from the Islamic State.

U.S. military officials have not publicly stated which groups will participate in the Raqqah operation or whether the United States will seek to strengthen the capacity of partner forces through the provision of weapons (or more advanced weapons). Some of the capability gaps among local partner forces have been addressed to date through the deployment of additional U.S. personnel to Syria.

Ongoing U.S. Presence in Manbij U.S. military personnel continue to operate in the northern Syrian town of Manbij, located in Aleppo province roughly 40 km from the Turkish border. SDF forces captured Manbij from the Islamic State in August 2016, and coalition forces remained in the city. Following the expulsion of IS forces from Manbij, Turkey expressed concern that Kurdish YPG fighters might retain a permanent presence in the city, putting the group a step closer to establishing a contiguous area of Kurdish control along the Turkish border (see Figure 3). Less than two weeks after the SDF operation in Manbij, Turkish forces crossed into northern Syria in what it termed Operation Euphrates Shield (see "Turkish-Supported Operations in Syria," below).

The defeat of Islamic State forces in Manbij created new challenges for the United States, including the issue of who would govern the city. While Russia stated in March 2017 that Syrian government forces would take over government administration in Manbij,⁴⁷ governance in the city has been assumed by the Manbij Military Council. According to a U.S. military spokesperson, coalition forces in Manbij continue to "train, advise, assist and accompany" Manbij Military Council forces as they provide security and restore governance.⁴⁸

In early March 2017, approximately 100 Army Rangers were deployed to Manbij. The visible deployment of additional U.S. forces to Manbij appeared designed to deter conflict between rival groups in the vicinity, which include Kurdish, Turkish, Russian, and Syrian forces. In early March, Turkish Foreign Minister Mevlut Cavusoglu stated that Turkey would attack Manbij unless the Kurds withdrew from the city, and Russian-backed Syrian government forces interposed themselves between Turkish-supported forces and Manbij.⁴⁹ A U.S. military spokesperson stated that the U.S. presence in Manbij "improves transparency and facilitates communication among all parties in the area to avoid misunderstanding and miscalculation."⁵⁰ He acknowledged that U.S. and Russian forces in Manbij are in close enough proximity that they can visually observe one another's movements, and that communication between the two continues to increase via the deconfliction channel.⁵¹

In a March 9, 2017, Senate Armed Services Committee hearing, Chairman John McCain voiced concern about potential Turkish-YPG conflict affecting U.S. interests in Syria—possibly including the U.S.-led coalition's continued use of Turkey's Incirlik air base—to General Joseph Votel. General Votel responded that U.S. officials are trying to prevent such potential conflict.⁵²

Turkish-Supported Operations in Syria Turkish operations inside Syria (known as Operation Euphrates Shield) began in August 2016, and were designed to counter both Islamic State and Kurdish forces operating along Turkey's southern border with Syria.⁵³ Turkish forces have worked with allied Syrian forces (mostly Arabs and Turkmen nominally opposed to the Asad regime) to counter IS fighters, but also occasionally clashed with Syrian Kurdish-led forces. In February 2017, Turkish forces partnered with Syrian rebels entered the Syrian town of Al Bab after more than three months of clashes. The town, a key transport hub, had been controlled since 2014 by the Islamic State. In late February, Turkish forces backed by coalition airstrikes recaptured the town.⁵⁴ Turkey's incursion into Syria and operations in Al Bab appeared to reflect Turkish concerns that the YPG fighters in Syria could create a contiguous area of Kurdish control along the Turkish border. Manbij and Al Bab are located between two areas (shaded yellow in Figure 3) that are largely controlled by Kurdish-led forces and roughly correspond to the "cantons" of Afrin and Kobane subject to Syrian Kurdish political claims.

Turkey considers the PYD/YPG to be the Syrian arm of the Kurdistan Workers Party (PKK), which both Turkey and the United States have designated as a terrorist group. Turkey appears to view the YPG as the top threat to its security, given the operational and moral support YPG military and political success could provide to the PKK's insurgency within Turkey.⁵⁵ The United States does not view the PYD/YPG as a terrorist organization.⁵⁶ However, a number of sources point to evidence of close and continuing operational and personnel links between the PKK and PYD/YPG.⁵⁷

In late March 2017, Turkish leaders announced that Operation Euphrates Shield had been "successfully completed," but did not specify when or if Turkish troops would withdraw from Syria.⁵⁸ Turkish Prime Minister Yildirim noted that Turkey could launch further military operations if necessary, under a different name.

For additional background, see CRS Report R41368, Turkey: Background and U.S. Relations, by [author name scrubbed] and [author name scrubbed], and CRS Report R44513, Kurds in Iraq and Syria: U.S. Partners Against the Islamic State, coordinated by [author name scrubbed].

Anti-Asad Groups Battle, Reorganize in Northern Syria

Intrarebel fighting in Idlib Province and northwest Aleppo Province intensified in January 2017, apparently driven by some groups' fears of further setbacks in the wake of the late 2016 fall of east Aleppo and some hard-liners' desire to consolidate their positions and dissuade other opposition forces from participating in peace talks.⁵⁹ After launching raids against other rebel groups, Jabhat Fatah al Sham (the Levant Victory Front/JFS, formerly known as the Al Qaeda-affiliated Nusra Front) and a number of other Salafist combatant groups announced their intention to disband and recombine under the auspices of a new entity, known as Hai'a Tahrir al Sham (Levant Liberation Assembly, aka Tahrir al Sham).⁶⁰

Figure 3. Syria-Turkey Border

As of April 4, 2017

Source: Areas of influence based on data from IHS Conflict Monitor, and adapted by CRS based on media accounts. Other sources include UN OCHA and Esri.

The new configuration reportedly remains dominated by former JFS fighters and leaders, with former Nusra Front/JFS leader Abu Mohammed al Jolani serving as its military commander. Tahrir al Sham leaders claim to command more than 30,000 fighters from their nominally united constituent groups, although this figure may be inflated.⁶¹ A hard-line former leader of northern Syria's other large Islamist opposition coalition—Ahrar al Sham (Free Men of the Levant)—has been named Tahrir al Sham's "general commander,"⁶² and some Ahrar al Sham factions reportedly have defected to Tahrir al Sham's ranks, presumably drawn in part by their opposition to ongoing peace talks and based on loyalty to commanders.

It remains to be seen whether members of other northern Syria-based opposition groups, including some that have battled with JFS and its allies since late 2016, will choose unity or conflict with Tahrir al Sham.⁶³ Some have already moved to join with Ahrar al Sham and may seek to form a coalition more open to participation in negotiations with the regime.

Some members of Tahrir al Sham reportedly expect their new coalition to avoid designation and targeting by the United States and other third parties as a terrorist entity, in spite of the participation of former JFS leaders and personnel.⁶⁴ U.S. strikes on JFS personnel have continued in early 2017, including a January 20 raid that reportedly killed 100 JFS personnel at a training camp in Idlib Province.

Political Negotiations The Geneva Process

Since 2012, the Syrian government and opposition have participated in U.N.-brokered negotiations under the framework of the Geneva Communiqué. Endorsed by both the United States and Russia, the Geneva Communiqué calls for the establishment of a transitional governing body with full executive powers. According to the document, such a government "could include members of the present government and the opposition and other groups and shall be formed on the basis of mutual consent."⁶⁵ The document does not discuss the future of Asad.

Subsequent negotiations have made little progress, as both sides have adopted differing interpretations of the agreement. The opposition has said that any transitional government must exclude Asad. The Syrian government maintains that Asad was reelected (by referendum) in 2014,⁶⁶ and notes that the Geneva Communiqué does not explicitly require him to step down. In the Syrian government's view, a transitional government can be achieved by simply expanding the existing government to include members of the opposition. Asad has also stated that a political transition cannot occur until "terrorism" has been defeated.

In February and March 2017, representatives from the Syrian government and Syrian opposition groups met for two rounds of indirect talks in Geneva, facilitated by U.N. Envoy Staffan de Mistura. The talks have not made significant progress.

The Astana Process

In December 2016, the foreign and defense ministers of Russia, Iran, and Turkey met in Moscow to discuss a political resolution to the Syrian conflict. The parties issued a joint statement, which laid out a set of principles for a future peace deal. While acknowledging that the United States was not asked to participate in the talks, a State Department spokesperson characterized the joint statement as "borrowing […] from ideas that the United States has led and pushed from the outset."⁶⁷ On December 29, Russia and Turkey announced a new cease-fire agreement to be followed by peace talks in Kazakhstan within a month, cosponsored by both countries.⁶⁸ On December 31, the U.N. Security Council unanimously adopted Resolution 2236, welcoming and supporting the Russian-Turkish initiative. In January 2017, Russia and Turkey hosted the first Syria peace talks in the Kazakh capital of Astana, which closed with few results.

A third round of peace talks in Astana was held on March 14-15. The Syrian rebel delegation did not attend, reportedly to protest a lack of adherence to the Russian-brokered cease-fire agreement.⁶⁹ A joint statement by Russia, Iran, and Turkey in March stated their intent to reconvene Astana peace negotiations in early May, although it is unclear whether subsequent developments will affect those plans.

Humanitarian Situation⁷⁰ Violence, insecurity, government and opposition interference, the closure of key border points, bureaucratic procedures, and resource shortfalls continued to hinder aid delivery, particularly to an estimated 4.7 million people in besieged and hard-to-reach areas.⁷¹ These included areas controlled by government forces or under opposition control and in eastern areas under Islamic State control.⁷²

During the Syria conflict, systematic violations of human rights and international humanitarian law (IHL) have been widespread by all parties, including the Islamic State.⁷³ Civilian protection concerns include mass executions, systematic rape and sexual violence, torture, and appalling treatment of those in detention. Lack of access, food insecurity, health concerns (injuries, disease outbreaks, serious medical conditions and disabilities), inadequate shelter, and an economic recession coupled with growing poverty contribute to the vulnerability of millions of civilians.

As of March 2017, an estimated 13.5 million people inside Syria, more than half the population, were in need of humanitarian and protection assistance, including 5.8 million children.⁷⁴ There are estimated to be more than 6.3 million Internally Displaced Persons (IDPs), but this number is imprecise and very fluid. Many Syrians, some of whom have been displaced multiple times within the country, leave their homes to escape violence and then return when conflict in their area decreases. It is not clear how many IDPs are affected by repeat displacements, nor if, or how often, they are included in IDP counts. In December 2016, U.N. sources estimated that 7 million people in Syria were food insecure and 12.8 million people were in need of health assistance.⁷⁵

In addition, more than 5 million Syrians have registered as refugees abroad, with most fleeing to countries in the immediate surrounding region as well as Europe.⁷⁶ Experts recognize that some fleeing Syrians have not registered as refugees and have chosen instead to blend in with the local population, living in rented accommodations and makeshift shelters, particularly in towns and cities. The U.N. Office for the Coordination of Humanitarian Affairs (UNOCHA) estimates that more than 90% of Syrian refugees are living outside camps in mostly urban settings, where refugees may be difficult to identify and assist. Interagency cross-line convoys and cross-border operations from Turkey and Jordan provided humanitarian assistance and protection services to millions of people across the country each month.⁷⁷

In December 2016, the United Nations, along with humanitarian partners, launched several 2017 appeals, including the Syria Regional Refugee and Resilience Plan (3RP) for $5.6 billion; and the Humanitarian Response Plan (HRP) for Syria for $3.4 billion.

Since 2011, U.N. appeals have consistently remained underfunded, which in 2015 resulted in cuts to food aid and cash assistance. According to UNHCR, chronic funding shortages greatly limit aid programs for refugees and host communities in the region. Lack of assistance is reportedly leading to an increase in negative coping strategies, such as begging, child labor, survival sex, and higher debt. Deepening poverty, lack of legal work options, limited education, and insecurity are attributed to the decision by some to leave and risk the dangerous journey away from the region, with many fleeing to Europe and expanding the impact of the crisis.⁷⁸

As of April 7, 2017, the 2017 3RP appeal was 26% funded and the appeal for Syria was 14.7% funded.⁷⁹ At a February 2016 conference in London, donors pledged $11.3 billion for the Syria crisis, of which $5.9 billion was for 2016 and $5.4 billion for 2017-2020. Multilateral development banks and donors also announced $41 billion in loans.⁸⁰ In March 2017, donors pledged a combined $6 billion for humanitarian programs in 2017 and $3.7 billion for 2018.⁸¹

U.S. Humanitarian Assistance

The United States is the largest donor of humanitarian assistance to the Syria crisis. Since FY2012, it has allocated more than $6.5 billion to meet humanitarian needs using existing funding from global humanitarian accounts and some reprogrammed funding.⁸² U.S. humanitarian policy is guided by concerns about humanitarian access and protection within Syria, the large refugee flows out of the country that strain the resources of neighboring countries (and could negatively impact the overall stability of the region), and a significantly protracted and escalating humanitarian emergency.

The Obama Administration's FY2017 budget request sought nearly $6.2 billion in global humanitarian assistance. This included $2.1 billion for Syria in Overseas Contingency Operations (OCO) funds provided through the Migration and Refugee Assistance (MRA) and International Disaster Assistance (IDA) accounts to address the humanitarian impact of the crisis. An additional $1.2 billion supplemental was later requested.⁸³ In the Further Continuing and Security Assistance Appropriations Act, 2017 (P.L. 114-254), OCO funding, which is exempt from discretionary spending limits, was continued at FY2016 levels, with additional funds to counter the Islamic State provided in several accounts, including $300 million for MRA and $616.1 million for IDA. In addition, $1 billion in Economic Support Funds-OCO (ESF-OCO) was appropriated for stabilization and community support in Syria and other countries affected by the Islamic State. It is not yet known how the Trump Administration plans to address the Syria humanitarian situation in its FY2018 budget request.

U.S. Policy and Assistance U.S. Strategy and Policy

The central question for U.S. policy toward the Syria conflict since 2011 has been whether or not the United States should support and pursue a resolution of the conflict that would recognize a continuing role for Syrian President Bashar al Asad. Policy proposals over time have reflected various assumptions about whether Asad's continued rule or its end would bring the conflict to a close. Counterterrorism and regional stability concerns became amplified by developments in Syria's underlying conflict and arguably, in the case of the Islamic State, took precedence over U.S. concerns about Asad's future. U.S. and regional policymakers have sought to determine which problem in Syria to confront first–Asad or the Islamic State—and U.S. officials and observers have debated how different approaches and outcomes would affect Syria's short- and long-term stability.

Since taking office in January 2017, President Trump has stated his intention to "destroy" the Islamic State, and the President has ordered actions to "accelerate" U.S. military efforts against the group in Syria and Iraq. In late March, senior U.S. officials signaled that the United States would prioritize the fight against the Islamic State over efforts to ensure that Asad leaves office, marking an apparent shift from the approach initially articulated by the Obama Administration. Nevertheless, in the wake of the April chemical weapons attack, President Trump and senior members of his Administration have spoken critically of Asad's leadership, and it remains to be seen whether the United States will more directly seek to compel Asad's departure from power while pursuing the ongoing campaign against the Islamic State.

On April 6, Secretary of State Rex Tillerson outlined the Trump Administration's vision for the sequencing of U.S. efforts, subject to developments in Syria:

Overall, the situation in Syria is one where our approach today and our policy today is first to defeat ISIS. By defeating ISIS, we remove one of the disruptive elements in Syria that exists today. That begins to clarify, for us, opposition forces and regime forces, and working with the coalition—as you know, there is a large coalition of international players and allies who are involved in the future resolution in Syria.

So it's to defeat ISIS; it's to begin to stabilize areas of Syria, stabilize areas in the south of Syria, stabilize areas around Raqqa, through cease-fire agreements between the Syrian regime forces and opposition forces; stabilize those areas, begin to restore some normalcy to them, restore them to local governments—and there are local leaders who are ready to return, some who've left as refugees that are ready to return, to govern these areas; use local forces that will be part of the liberation effort to develop the local security forces—law enforcement, police force; and then use other forces to create outer perimeters of security so that areas like Raqqa, areas in the south, can begin to provide a secure environment so refugees can begin to go home and begin the rebuilding process.

In the midst of that, through the Geneva process, we will start a political process to resolve Syria's future in terms of its governance structure. And that ultimately, in our view, will lead to a resolution of Bashar al-Assad's departure.⁸⁴

U.S. Assistance to Syrians and the Syrian Opposition

A broad set of bilateral U.S. sanctions on Syria existed prior to the outbreak of conflict, and some, such as those triggered by Syria's designation as a state sponsor of terrorism, initially had a limiting effect on the delivery of U.S. assistance in the country. The FY2014 Consolidated Appropriations Act (Section 7041[i]) of Division K of P.L. 113-76) significantly expanded the Administration's authority to provide nonlethal assistance in Syria for certain purposes using the Economic Support Fund (ESF) account. Such assistance had been restricted by a series of preexisting provisions of law (including some terrorism-related sanctions provisions) that required the President to assert emergency and contingency authorities (i.e., Sections 451 and 614 of the Foreign Assistance Act of 1961, as amended) to provide such assistance to the unarmed Syrian opposition and communities in Syria. Such assistance has been provided to select unarmed opposition groups on a periodic basis since May 2012, although the Administration has not publicly released a detailed accounting or list of recipients. Congressional committees of jurisdiction are notified when the Administration intends to obligate funds for these purposes.

The FY2014 assistance authorities, as expanded and extended by the FY2015 Appropriations Act (Section 7041[h] of P.L. 113-235), made FY2015 and prior year ESF funding available "notwithstanding any other provision of law" for select nonlethal purposes. The FY2016 Appropriations Act (Section 7041[h] of P.L. 114-113) extended this authority further, granting notwithstanding exceptions for FY2016 ESF funds as well as for FY2016 funds in the International Narcotics Control and Law Enforcement (INCLE) and Peacekeeping Operations (PKO) accounts. The Obama Administration used the INCLE and PKO accounts to support justice sector activities in opposition-held areas of Syria and to provide nonlethal assistance to select armed opposition groups. The FY2016 appropriations act authorizes "non-lethal assistance for programs to address the needs of civilians affected by conflict in Syria, and for programs that seek to—

(A) establish governance in Syria that is representative, inclusive, and accountable;

(B) expand the role of women in negotiations to end the violence and in any political transition in Syria;

(C) develop and implement political processes that are democratic, transparent, and adhere to the rule of law;

(D) further the legitimacy of the Syrian opposition through cross-border programs;

(E) develop civil society and an independent media in Syria;

(F) promote economic development in Syria;

(G) document, investigate, and prosecute human rights violations in Syria, including through transitional justice programs and support for nongovernmental organizations;

(H) counter extremist ideologies;

(I) assist Syrian refugees whose education has been interrupted by the ongoing conflict to complete higher education requirements at regional academic institutions; and

(J) assist vulnerable populations in Syria and in neighboring countries.

The acts require the Secretary of State to "take all appropriate steps to ensure that mechanisms are in place for the adequate monitoring, oversight, and control of such assistance inside Syria," and require the Secretary of State to "promptly inform the appropriate congressional committees of each significant instance in which assistance provided pursuant to the authority of this subsection has been compromised, to include the type and amount of assistance affected, a description of the incident and parties involved, and an explanation of the Department of State's response."

The acts further require the Obama Administration to submit a comprehensive interagency strategy prior to using the authorities that includes a "mission statement, achievable objectives and timelines, and a description of inter-agency and donor coordination and implementation of such strategy." The strategy, which may be classified, must also include "a description of oversight and vetting procedures to prevent the misuse of funds." All funds obligated pursuant to the authorities are subject to established congressional notification procedures.

Foreign operations legislation under consideration inconsidered in the 114^th Congress would extendhave extended and/or add and amendadded to and amended these authorities for some FY2017 funds. The FY2016 terms apply by reference to FY2017 funds available under the current continuing appropriations resolution (H.R. 2028). these authorities for some FY2017 funds (see comparison in Table 1). The House version of the FY2017 foreign operations appropriations bill (H.R. 5912) would extend the notwithstanding authority for ESF funding and amend some authorized purposes. The Senate version (S. 3117) would extend the notwithstanding authority for the same three accounts as FY2016 (ESF, INCLE, and PKO) and would amend and add the authorized purposes of assistance.

Nonlethal Assistance to Armed Syrian Opposition Elements

Until the creation of the Syria Train and Equip program in 2014 discussed below, overt U.S. assistance to armed opposition forces remained restricted to nonlethal items. Prior to the creation of the program and the extension of the FY2016 foreign assistance authorities discussed above, congressional appropriators and authorizers had not provided the Administration with notwithstanding authority to provide nonlethal assistance to armed opposition groups. For that purpose, the Obama Administration had relied upon special authorities granted by the Foreign Assistance Act of 1961, as amended (Section 552[c] and Section 614).

In 2012, the Administration began to use these special authorities to provide food rations and medical supplies to the National Coalition of Revolutionary and Opposition Forces (SOC) and the Turkey-based Syrian Military Council (SMC). Since then, U.S. assistance has expanded to encompass a range of smaller, local groups. In August 2015, the State Department reported,

Non-lethal assistance is being provided to a range of civilian opposition groups, including local councils, civil society organizations, and SOC-affiliated entities to bolster their institutional capacity, create linkages among opposition groups inside and outside Syria, and help counter violent extremism. These efforts enable the delivery of basic goods and essential services to liberated communities as they step in to fill voids in local governance. In addition to civil administration training programs, we have provided opposition groups with a wide array of critical equipment, including generators, ambulances, cranes, dump trucks, fire trucks, water storage units, search and rescue equipment, educational kits for schools, winterization materials, and commodity baskets for needy families in the local community.⁶⁷85

This equipment is used to bolster governance by providing services such as emergency power, sanitation, water, and education services. Other U.S. assistance provided under authorities granted by Congress in FY2014-FY2016 appropriations acts and the FY2017 continuing resolution supports the maintenance of public safety, rule of law, and the documentation of human rights violations.

Obama Administration officials have noted that U.S. efforts to deliver and monitor security assistance and other aid inside Syria have been hindered by border closures, ongoing fighting, and risks from extremist groups. Some U.S. nonlethal assistance to armed opposition groups has fallen into the hands of unintended recipients and has led to changes in delivery and oversight mechanisms.⁶⁸86 Infighting among some opposition forces, the empowerment of the Islamic State in Syria, and concerns expressed by other outside actors such as Russia and Turkey have created further complications. Although the Islamic State has lost control of border crossings it formerly held, other anti-U.S. extremist groups control some border crossings in northwestern Syria. As such, access issues may continue to hinder efforts to expand support to anti-IS forces.

In July 2016, the Government Accountability Office released a report examining the delivery of nonlethal assistance to Syria. The report recommended that the Department of State, USAID, and their implementing partners incorporate greater oversight of fraud risk in the delivery of such aid.⁶⁹87

Syria Train and Equip Program⁷⁰

88

The establishment of the Syria Train and Equip program by Congress in 2014 represented a further evolution of the involvement of the United States in supporting Syrian opposition groups. Several hundred U.S. military training personnel and a similar number of support personnel deployed in support of the program, which Congress authorized to train and equip vetted Syrians to fight the Islamic State, defend against terrorist threats, and promote "the conditions for a negotiated settlement to end the conflict in Syria." According to Obama Administration officials, the program originally was designed to recruit, vet, train, and equip a force of 5,400 Syrians per year for each of three years. However, challenges in implementation significantly limited the program's output in 2015, and in October 2015, officials announced plans for a significant shift in the program's focus toward equipping select vetted fighters inside Syria and away from training and equipping new units in neighboring countries.

The shift from training and equipping of new vetted units toward equipping existing vetted armed groups has featured some unique risks. While equipment losses have not proven to be a major systemic concern since the change was announced, some Syrian opposition groups that reportedly have received U.S. equipment and weaponry have surrendered or lost these items to other groups, including to the Islamic State.⁷¹89 The comprehensive training approach under the program's first iteration sought to create unit cohesion, groom and support reliable leaders to serve as U.S. partners, and inculcate a spirit of nationalist motivation among fighters in the place of local, sectarian, or ideological goals. The amended approach appears to have more rapidly and effectively equipped some anti-IS forces in some areas of Syria, but it has had less apparent and quantifiable effects on the development and practices of opposition forces that may influence security in Syria for years to come. Increased reliance on vetted group leaders may also have reduced U.S. visibility and influence over which individual fighters receive U.S. weapons.

Related Appropriations and Authorities

Of the $500 million in Counterterrorism Partnerships Fund (CTPF) monies approved by congressional defense committees for the Train and Equip program in FY2015, $384 million was obligated as of September 30, 2015, with $116 million transferred back to the Fund at the end of the fiscal year to preserve its availability in FY2016. The $116 million were subsequently transferred back out of the CTPF to various operations and maintenance accounts for program activities in November 2015.

The FY2016 NDAA (P.L. 114-92) authorized $406.45 million in funding for the program, less than the Obama Administration's request for $600 million. FY2016 defense appropriations legislation (H.R. 2685, S. 1558) would have provided $600 million for the program on different terms. However, the omnibus appropriations act for FY2016 did not appropriate

funding for the Syria Train and Equip Fund, but it allows the Secretary of Defense to use funds from the Counterterrorism Partnerships Fund for efforts to assist appropriately vetted elements of the Syrian opposition, if the Secretary outlines a detailed and clear plan for the use of such funds and provides such justification to the congressional defense committees in a reprogramming request.⁷²90

In March 2016, the Obama Administration requested congressional approval to reprogram $300 million in FY2016 CTPF funding to support the continuation of the program. The congressional defense committees approved the reprogramming action after a period of review and debate.⁷³ In total, Congress has reviewed and approved Defense Department requests to reprogram more than $1.03 billion in monies from other accounts for the program since 2014.

91 The Obama Administration's FY2017 request included $250 million in defense funding to train, equip, and/or sustain appropriately vetted Syrian forces engaged in the fight against the Islamic State.⁷⁴ Of the amount requested, $210.8 million would support the procurement and provision of weapons, ammunition, and equipment; $18.6 million would support lift and transportation costs; and $20.6 million would support trainee stipends and operational sustainment.

Not having reached an agreement on an annual budget by the start of FY2017, Congress passed two continuing resolutions (CRs). The first CR for FY2017—H.R. 5325—provided budget authority through December 9, 2016, and was extended by H.R. 2028, the Further Continuing and Security Assistance Appropriations Act, 2017, until April 28, 2017. Both CRs provided funding for Overseas Contingency Operations (OCO) at the FY2016 appropriated levels. Division B of H.R. 2028 provides an additional $5.8 billion in supplemental OCO appropriations for DOD and $4.3 billion in supplemental OCO appropriations for State, Foreign Operations and Related programs. The combined funding provides the incoming Administration with resources to continue prevailing lines of effort against the Islamic State and reflects the Obama Administration's November 2016 amended budget request92 In total, Congress has reviewed and approved Defense Department requests to reprogram more than $1.25 billion in monies from other accounts for the program since 2014.

Funding transfers for the Syria train and equip program will remain subject to the prior approval of congressional defense and appropriations committees pursuant to the terms of the FY2017 NDAA (S. 2943), which extended the authorization for the program through December 31, 2018, and authorized the appropriation of funds for the program in a new $1.16 billion "Counter-ISIL" fund to support Iraq and Syria training activities.

Other Reported U.S. Assistance

Then-Secretary of Defense Chuck Hagel said in a September 2013 hearing before the Senate Foreign Relations Committee that the Obama Administration was taking steps to provide arms to some Syrian rebels under covert action authorities.⁸¹99 Several press accounts citing unnamed U.S. government sources subsequently described details of reported U.S. and partner nation efforts to that effect.⁸²100 To date, other U.S. officials have not publicly acknowledged any such efforts or publicly described which elements of the Syrian opposition may have received U.S. training or support via any such channels, what any training may have entailed, what types of weaponry may have been provided, or what safeguards may be in place to monitor the disposition of equipment and the actions of any U.S.-trained or equipped personnel. One June 2015 article discussed differences of opinion among Members of Congress about future funding for the reported program.⁸³101 In October 2015, unnamed U.S. officials were cited in press reports that suggested that Russia was actively targeting Syrian opposition groups that had received covert support from the United States.⁸⁴

102

Chemical Weapons and Disarmament⁹⁶

114

A major policy concern of the United States has been the use or loss of control of chemical weapons in Syria during the ongoing civil war. Syrian opposition sources and Syrian government officials have repeatedly traded allegations concerning the use of chemical weapons and toxic chemicals as weapons of war since late 2012.⁹⁷ Several governments—including the governments of Syria and the United States—have submitted allegations of chemical attacks to the U.N. Secretary General and/or the Organization for the Prohibition of Chemical Weapons (OPCW).⁹⁸ The United States, the United Nations,⁹⁹ and other countries have assessed that the Syrian government has used chemical weapons repeatedly against opposition forces and civilians in the country. Expert teams affiliated with the U.N. Mission to Investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic and the OPCW Fact Finding Mission in Syria have investigated some of these allegations and have found evidence that in some cases confirms and in others suggests that chemical weapons and/or toxic chemicals have been used in attacks by the Syrian regime and by the Islamic State. Syrian civilians, opposition fighters, and military personnel have been targeted in alleged attacks.¹⁰⁰The reported use of nerve agent by aerial bombardment on April 4, 2017, in the town of Khan Sheikhoun in rebel-held Idlib province killed an estimated 80 to 100 people and returned the issue of chemical weapons in Syria to center stage. Secretary of State Tillerson said that the U.S. government had a "very high level of confidence" that the Syrian air force had used the nerve agent sarin in three recent attacks—on March 25, March 30, and April 4.¹¹⁵

On April 6, the United States responded with missile strikes against Al Shayrat air base which Pentagon officials stated is used to store chemical weapons.¹¹⁶ President Trump said that "It is in the vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons."¹¹⁷ Secretary of State Rex Tillerson also said the U.S. strike was aimed at reestablishing the norm against chemical weapons use:

As Assad has continued to use chemical weapons in these attacks with no response—no response from the international community—that he, in effect, is normalizing the use of chemical weapons, which may then be adopted by others. So it's important that some action be taken on behalf of the international community to make clear that the use of chemical weapons continues to be a violation of international norms.¹¹⁸

The World Health Organization said on April 5 that it was alarmed by the use of chemicals in Syria the previous day.¹¹⁹ The Turkish Ministry of Health said on April 6 that it had assessed that victims of the attack were exposed to sarin.¹²⁰

The largest-scale use of chemical weapons to date was reportedly an August 21, 2013, nerve gas attack, which the U.S. government estimated killed over 1,400 people.¹⁰¹121 In August 2013, the Obama Administration had threatened military action against Syria in response to alleged nerve gas attacks by Syrian government forces. As part of a diplomatic solution to the crisis based on a U.S.-Russian joint proposal, the Administration withdrew the threat of military force and Syria agreed to give up its chemical weapons and join the international Chemical Weapons Convention (CWC), which bans the use of any toxic chemicals in warfare and requires Syria to destroy all of its chemical weapons stocks and production facilities under international supervisionChemical Weapons Convention (CWC). U.N. Security Council Resolution 2118 (2013) further mandated that Syria give up all its chemical weapons under Chapter VII provisions of the U.N. Charter.¹⁰²122

At the start of the war, Syria had more than 1,000After joining the CWC, Syria declared that it possessed 1,300 metric tons of chemical warfare agents and precursor chemicals, including several hundred metric tons of the nerve agent sarin, several hundred metric tons ofagents sarin and VX, as well as mustard agent in ready-to-use form, and several metric tons of the nerve agent VX. The nerve agents were stored as two separate components that are combined before use, a form that facilitated removal and destruction efforts. The international community oversaw the removal and destruction of these chemical weapons agents from Syria, and, as of January 4, 2016, all declared Category 1 and 2 declared chemicals had been destroyed.¹⁰³123

Destruction of chemical weapons facilities is still underway,¹⁰⁴124 and the United States has raised questions over whether Syria has declared all of its chemical weapons stocks. The OPCWOrganization for the Prohibition of Chemical Weapons (OPCW) has not been able to verify the completeness of the declaration, part of Syria's obligations under the CWC. The OPCW's Declaration Assessment Team (DAT) continues to investigate "gaps, inconsistencies and discrepancies" through interviews and lab analysis of samples from site visits but the cooperation of the Syrian government has been limited and little progress has been made according to the August 2016 OPCW Executive Council report.¹⁰⁵

Reports of chemical weapons use in Syria continue.125 Press reports and nongovernment experts speculate that the Asad regime may have used undeclared stocks of nerve agent in the April 4 attack.¹²⁶

Reports of the use of chlorine gas as a chemical weapon began to surface in April 2014. The OPCW established a fact-finding mission to investigate these allegations. Several governments—including the governments of Syria and the United States—have submitted allegations of chemical attacks to the U.N. Secretary General and/or the OPCW.¹²⁷ The United States, the United Nations,¹²⁸ and others have assessed that the Syrian government has used chemical weapons repeatedly against opposition forces and civilians in the country. Expert teams affiliated with the U.N.-OPCW Joint Mission to Investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic and the OPCW Fact Finding Mission in Syria have investigated some of these allegations and have found evidence that in some cases confirms and in others suggests that chemical weapons and/or toxic chemicals have been used in attacks by the Syrian regime and by the Islamic State. Syrian civilians, opposition fighters, and military personnel have been targeted in alleged attacks.¹²⁹

Reports of chemical weapons use in Syria continue, consisting primarily accusations of chlorine use in barrel bombs until the alleged sarin use in the spring of 2017.¹³⁰ Earlier U.N. and OPCW investigations had not been tasked with assigning responsibility for alleged attacks but with identifying whether chemical weapons were used. However, on August 7, 2015, the U.N. Security Council unanimously adopted Resolution 2235, which established a new OPCW-UN Joint Investigative Mechanism (JIM) tasked with identifying "to the greatest extent feasible" those responsible for or involved in chemical attacks identified by the OPCW fact finding mission.¹⁰⁶131 In September 2015, the United Nations Security Council adopted the Secretary General's proposal for the establishment of the OPCW-UN JIM, and the Secretary General appointed Virginia Gamba of Argentina to head the independent three-member panel that leads the JIM.

While Resolution 2235 empowers the JIM to have access anywhere in Syria, the JIM's mission has been complicated by the security situation on the ground. The JIM initially investigated nine attacks alleged to have occurred between April 2014 and August 2015. Of these, three cases lacked sufficient evidence to draw conclusions, three cases require further investigation, and three cases were concluded. Eight of the cases involved chlorine-filled barrel bombs. The JIM submitted its third report on August 24, 2016, and its fourth report on October 21, 2016. The reports attributed four cases of chemical weapons use.¹⁰⁷132 According to the report

• bombs with toxic chemicals (such as chlorine) were dropped in Talmenes in April 2014 by the Syrian Air Force;
• bombs with toxic chemicals (such as chlorine) were used in Qmenas in March 2015 by the Syrian Armed Forces;
• bombs with toxic chemicals (such as chlorine) were used in Sarmin in March 2015 by the Syrian Air Force; and,
• mortar shells filled with sulfur mustard were used by the Islamic State in Marea in August 2015.¹⁰⁸133

The Security Council extended the mandate of the JIM for another yearthrough 2017 despite initial objections by Russia, who argues for a wider regional mandate.¹⁰⁹134 The JIM's mandate will remain limited to investigating alleged incidents of chemical weapons use in Syria, but will also include outreach to the UNSC's nonproliferation committee and neighboring states regarding nonstate use of chemical weapons. The United States worked to extend the JIM, in order to "send a clear message that the use of chemical weapons will not be tolerated."¹¹⁰

Press and social media continue to report said that the Syrian government has been using chlorine in barrel bombs in Aleppo and other locations. 135 The Syrian government continues to deny categorically that it has used chemical weapons or toxic chemicals, while accusing opposition forces of doing so and calling into question the methods and results of some investigations into alleged chemical attacks.¹¹¹136 The U.N. representatives of the United States, France, and the United Kingdom continue to cite information they believe suggests Syrian government complicity in conducting ongoing chemical attacks, particularly with chlorine.

An effort in February 2017 to pass a Security Council Resolution that would sanction Syria failed to get the votes of Russia or China.¹³⁷ The latest incidence of use on April 4 has elevated these issues again to the U.N. Security Council.

Additional press reports have reported on possible past use of mustard gas in Syria and Iraq by IS fighters.¹¹²138 U.S. Brigadier General Kevin Killea, chief of staff for military operations in Iraq and Syria, said that the United States was conducting testing to confirm these reports, which to date have not been officially confirmed by U.S. or U.N. investigations. The OPCW's chief has said that the Islamic State has produced and used sulfur mustard in northern Iraq and Syria.¹¹³139 U.S. forces struck Islamic State sites in Iraq believed to be associated with chemical weapons production in September 2016, and a multilateral effort removed chemical weapons precursors from Libya in August 2016 after Islamic State affiliate forces threatened the area where the materials had been stored. The Pentagon has said that U.S. troops fighting in Iraq are expected to continue to face weaponized mustard gas attacks by the Islamic State.¹¹⁴

Outlook

Russia's military intervention in Syria has reframed many of the policy questions that U.S. policymakers have grappled with since the outbreak of conflict there in 2011. In broad terms, the Obama Administration argued that pressure must be brought to bear on the Syrian government in order to convince its leaders to negotiate a settlement to the conflict that would result in President Asad's departure from office and the preservation of Syrian state institutions. Asad and Russia fundamentally reject this view140 Outlook

The full effects of the April chemical weapons attack in Syria and subsequent U.S. strike on Syrian government targets are still to be determined. As noted above, President Trump and his Administration have expressed increased concern about Syrian President Bashar al Asad and skepticism regarding the legitimacy of his continued rule in the wake of these developments. If the military impact of the U.S. strikes is limited and if the Trump Administration clarifies its views to reflect its previously stated emphasis on combatting the Islamic State, then a situation approximating the status quo ante may prevail. Namely, the Asad government may continue to consolidate its control over populous areas of western Syria while reconstituting its forces to raid opposition-held areas in the northwest and guard against Islamic State reinfiltration from the east. Alternately, if further strikes are taken and U.S. confrontation with the Syrian government and its Russian and Iranian patrons deepens, then U.S. military operations in Syria targeting the Islamic State may become more difficult.

Speaking on April 7, U.S. Permanent Representative to the United Nations Ambassador Nikki Haley spoke of "a new phase" and "a drive toward a political solution," following Secretary of State Tillerson's outline of U.S. goals for Syria on April 6.¹⁴¹ That outline prioritizes action against the Islamic State in pursuit of a political solution "that ultimately, in our view, will lead to a resolution of Bashar al Asad's departure."¹⁴² Asad and Russia fundamentally reject calls for Asad's departure and argue that "counterterrorism" cooperation with the Syrian government against its adversaries should precede further discussion of transition arrangements. Efforts to forcefully compel Asad's departure or empower opposition groups to depose Asad may risk direct confrontation with Russian military forces, with potentially broad implications beyond Syria. At the same time, the risk remains that any perceived U.S. acquiescence to or cooperation with Russia's intervention on Asad's behalf risks alienating anti-Asad forces and their regional backers, as well as providing Russia with an opportunity to consolidate a new, active role for itself in regional security arrangements.

Over the longer term, Syria's diversity and the interplay of its conflict and regional sectarian rivalries raise the prospect of continued violence even in the wake of the type of "managed transition" that has at times been identified as a U.S. policy goal. The presence and power in Syria of armed groups directly opposed to the governance models promoted by many Syrians and the United States suggests that the conflict could persist after any negotiated settlement seeking to replace the current Asad-led government with a government of national unity or other inclusive formulation. Political opposition coalitions active internationally appear to lack grassroots support and, because of their lack of material control over the most powerful armed groups, they appear to lack the ability to guarantee security commitments that might presumably be part of a negotiated settlement. StateSome analysts doubt the Asad government could survive a partial transition and suggest state collapse could accompany efforts to replace it whether by negotiation or by force. Even under relatively favorable circumstances, state weakness may allow extremist and terrorist groups to operate from Syria for years to come.

Observers, U.S. officials, and Members of Congress continue to differ over which incentives and disincentives may prove most effective in influencing combatants and their supporters. Still less defined are the long-term commitments that the United States and others may be willing to make to achieve an inclusive political transition acceptable to Syrians; protect civilians; defend U.S. partners; promote accountability and reconciliation; or contribute to the rebuilding of a country destroyed by years of brutal war.

Appendix A. Syrian History and Demographics

Background: Syria, its People, and the Conflict

The Syrian Arab Republic emerged as an independent country during the Second World War after a period of French rule and nationalist unrest in the wake of the First World War. Prior to that, the territory that now comprises Syria was administered by the Ottoman Empire and had earlier been an important stage for major events in the founding of Christianity and Islam, Muslim-Christian battles during the Crusades, and the repulsion of the Mongol invasion of the Middle East. The country's strategic, central location made it a venue for superpower and regional competition during the Cold War era, and its current religious, ethnic, political, economic, and environmental challenges mirror those of some other countries in the Middle East.

Long before the current conflict, Syrians struggled with challenges that have bred deep dissatisfaction in other Arab autocracies, including high unemployment, high inflation, limited upward mobility, rampant corruption, lack of political freedoms, and repressive security forces. These factors fueled some opposition to Syria's authoritarian government, which has been dominated by the Baath (Renaissance) Party since 1963, and the Al Asad family since 1970. President Bashar al Asad's father—Hafiz al Asad—ruled the country as president from 1971 until his death in 2000. Beneficiaries of both the Asad family's rule and the economic and social status quo were drawn from across Syria's diverse citizenry; together, they offered support to the regime, helping it to manage, defuse, or repress dissent.

Syria's Diverse Population

The Syrian population, like those of many other Middle East countries, includes different ethnic and religious groups. For years, the Asad regime's strict political controls prevented these differences from playing an overtly divisive role in political or social life, whereas French and Ottoman administrators of Syria had at times manipulated popular divisions. A majority of Syrians, roughly 90% of the population, are ethnic Arabs; however, the country contains small ethnic minorities, notably Kurds, the country's largest distinct ethnic/linguistic minority (7%-10% of the total population). Of more importance in Syria are religious sectarian differences. In addition to the majority Sunni Muslims, who comprise over 70% of the population, Syria contains several religious sectarian minorities, including three smaller Muslim sects (Alawites, Druze, and Ismailis) and several Christian denominations. The Asad family are members of the minority Alawite sect (roughly 12% of the population), which has its roots in Shia Islam.

Despite the secular nature of the ruling Baath party, religious sects have been important to some Syrians as symbols of group identity and determinants of political orientation. The Asads and the Baath party have cultivated Alawites as a key base of support, and elite security forces have long been led in large part by Alawites, although some officers and most rank and file military personnel have been drawn from the majority Sunni Arab population and other minority groups. The government violently suppressed an armed uprising led by the Sunni Islamist Muslim Brotherhood in the early 1980s, killing thousands of Sunni Muslims and others.¹¹⁵

Religious, ethnic, geographic, and economic identities overlap in influencing the views and choices of Syrians about the current conflict. Within ethnic and sectarian communities are important tribal and familial groupings that often provide the underpinning for political alliances and commercial relationships. Socioeconomic differences abound among farmers, laborers, middle-class wage earners, public sector employees, military officials, and the political and commercial elite. Many rural, less advantaged Syrians originally supported the opposition movement, while urban, wealthier Syrians appeared to have mixed opinions. The decay of Syrian state institutions during the course of the conflict, especially in the security sector, appears to have empowered a new cadre of local actors whose ability to influence developments in areas under their immediate influence has complicated efforts by both the government and opposition groups to maintain law and order, security, and economic activity.

The viciousness of the conflict and the devastation it has brought to large areas of the country have further shaped the opinions of members of Syria's diverse population. Local and tribal attachments influence some Syrians, as seen in rivalries between the two largest cities, Damascus and Aleppo, in differences between rural agricultural communities and urban areas, and in the concentration of some sectarian and ethnic communities in discrete areas. Despite being authoritarian, Syrian leaders over the years often found it necessary to adopt policies that accommodated, to some degree, various power centers within the country's diverse population and minimized the potential for communal identities to create conflict.

That need is likely to remain, if not intensify, after the current conflict insofar as the conflict has contributed to a hardening of sectarian identities. While sectarian considerations cannot fully explain power relationships in Syria or predict the future dynamics of the conflict, accounts from Syria strongly suggest that some sectarian and ethnic divisions have grown deeper since 2011. Members of the Sunni Arab majority were at the forefront of the original protest movement in 2011, and predominantly Sunni Arab armed groups have engaged in most of the fighting against the security forces of the Alawite-led government. Support for the Asad government from foreign Shia fighters has galvanized some Sunnis' views of the regime as irretrievably sectarian. Nevertheless, much of the daily violence occurs between Sunni armed oppositionists and a Syrian military force composed largely of Sunni conscripts.

Syria's Christians, members of other minority groups, and civilians from some Sunni and Alawite communities have been caught between their parallel fears of what violent political change could mean for their communities and the knowledge that their failure to actively support rebellion may result in their being associated with Asad's crackdown and suffering retaliation. The Alawite leadership of the Syrian government and its allies in other sects appear to perceive the mostly Sunni Arab uprising as an existential threat to the Baath party's nearly five-decade hold on power. At the popular level, some Alawites and members of other sects may feel caught between the regime's demands for loyalty and their fears of retribution from others in the event of regime change or a post-Asad civil war.

Some Sunni Arabs may view the conflict as a means to assert their community's dominance over Alawites and others, but others may support the Asad government as an alternative to rule by extremist forces or out of fear of retaliation for past collaboration with the regime.¹¹⁶ Some Sunni opposition leaders have sought to assuage other groups' concerns about the implications of potential Sunni dominance, whereas others have demanded that non-Sunni groups accept Sunni religious rule. Some opposition figures have pledged their commitment to seeing that orderly trials and the rule of law prevail in any post-conflict setting. Nevertheless, reports of abuses at the hands of opposition forces suggest that leaders of many armed groups at times are unable or unwilling to ensure that such standards are applied consistently to their pro-Asad adversaries.

While some Kurds view the conflict as an opportunity to achieve greater autonomy, others are wary of supporting Sunni Arab rebels who, should they come to power, may be no less hostile to Kurdish political aspirations than the Asad government. Some members of Syria's various Christian communities have expressed fears that the uprising will lead to a sectarian civil war and that they could be subjected to violent repression, given that Muslim extremist groups have targeted Iraqi Christians in recent years. Other Christians reportedly have offered assistance to some elements of the armed opposition over time.

Appendix B. Parties to the Conflict

The following profiles offer limited descriptions of pro-Asad forces and select political and armed opposition forces. The profiles are based on open primary sources and CRS cannot independently verify the size, equipment, and current precise areas of operation of the armed groups described. At present, open source analysis of armed groups operating in Syria relies largely on the self-reporting of individual groups and coalitions. Information is not evenly and regularly available for all groups. The size and relative strength of groups vary by location and time. Many groups and units who claim to coordinate under various fronts and coalitions in fact appear to operate independently and reserve the right to change allegiances. The use of religious or secular imagery and messages by groups may not be reliable indicators of the long-term political aims of their members or their likely success in implementing those aims.

Footnotes

22. 75. 86. 127. 131. 138.

1.	"Terrorist Designations of the al-Nusrah Front as an Alias for al-Qa'ida in Iraq," Press Statement by State Department Spokesperson Victoria Nuland, December 11, 2012.
2.	President Barack Obama, Remarks by the President to the White House Press Corps, August 20, 2012.
3.	Action Group for Syria, Final Communiqué, June 30, 2012.
4.	Letter dated 22 March 2013 from the Secretary-General addressed to the President of the Security Council, U.N. Document S/2013/184, March 22, 2013.
5 Author Contact Information [author name scrubbed], Coordinator, Analyst in Middle Eastern Affairs ([email address scrubbed], [phone number scrubbed]) [author name scrubbed], Specialist in Middle Eastern Affairs ([email address scrubbed], [phone number scrubbed]) [author name scrubbed], Specialist in Nonproliferation ([email address scrubbed], [phone number scrubbed]) Footnotes
1.	President Trump Statement on Syria, April 6, 2016; and, Statement from Pentagon Spokesman Capt. Jeff Davis on U.S. strike in Syria, Release No: NR-126-17, April 6, 2017.
2.	Ibid.
3.	Statement from Pentagon Spokesman Capt. Jeff Davis on U.S. strike in Syria, Release No: NR-126-17, April 6, 2017.
4.	"Report: Russia Is Building a Second Military Airbase in Syria," Business Insider, December 3, 2015.
5.	"Dozens of U.S. Missiles Hit Air Base in Syria," New York Times, April 6, 2017.
6.	Statement by Secretary of Defense Jim Mattis on the U.S. Military Response to the Syrian Government's Use of Chemical Weapons, April 10, 2017.
7.	"Army Command: US Missile Attack Violates Int'l Laws, Makes the US a Partner of Terrorist Organizations," Syrian Arab News Agency, April 7, 2017.
8.	"Nine Civilians Killed in US Missile Attack in Homs," Syrian Arab News Agency, April 7, 2017.
9.	"Putin Calls US Strikes Against Syria 'Aggression Against Sovereign Country,'" TASS (Russia), April 7, 2017.
10.	"Russia Notifies Intent to Suspend Communication Channel: Coalition Official," Reuters, April 7, 2017.
11.	"Jets Launch Raids from Syria Base hit by US: Monitor," AFP, April 7, 2017.
12.	"Syria strikes: Site of chemical attack hit again," CNN, April 8, 2017.
13.	"U.S. bolsters protection of forces in Syria as tensions climb," Reuters, April 10, 2017.
14.	Megan Scully and Rachel Oswald, "No Plans for Future Strikes, White House Tells Lawmakers," CQ Roll Call, April 7, 2017.
15.	U.S. Permanent Representative to the United Nations Ambassador Nikki Haley, Remarks at a U.N. Security Council Meeting on the Situation in Syria, April 7, 2017.
16.	Prepared by Matthew Weed, Specialist in Foreign Policy Legislation.
17.	The letter says the strikes were intended "to degrade the Syrian military's ability to conduct further chemical weapons attacks and to dissuade the Syrian regime from using or proliferating chemical weapons, thereby promoting the stability of the region and averting a worsening of the region's current humanitarian catastrophe."
18.	"Terrorist Designations of the al-Nusrah Front as an Alias for al-Qa'ida in Iraq," Press Statement by State Department Spokesperson Victoria Nuland, December 11, 2012.
19.	President Barack Obama, Remarks by the President to the White House Press Corps, August 20, 2012.
20.	Action Group for Syria, Final Communiqué, June 30, 2012.
21.	Letter dated 22 March 2013 from the Secretary-General addressed to the President of the Security Council, U.N. Document S/2013/184, March 22, 2013.
The White House, Government Assessment of the Syrian Government's Use of Chemical Weapons on August 21, 2013, August 30, 2013. United Nations investigations confirmed that a chemical attack took place but its September and December 2013 reports did not address attribution. See U.N. Document A/67/997–S/2013/553, Report of the United Nations Mission to Investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic on the alleged use of chemical weapons in the Ghouta area of Damascus on 21 August 2013, September 16, 2013; and, United Nations Mission to Investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic, Final Report, December 2013.
623.	President Barack Obama, Remarks by the President Before Meeting with Members of Congress on the Situation in Syria, September 3, 2013.
724.	The FY2015 Continuing Resolution (P.L. 113-164, "the FY2015 CR") contained temporary authorization for the training and equipping of vetted Syrians that differed from the Administration's requests and expired on December 11, 2014. The FY2015 NDAA (Sections 1209, 1510, and 1534 of Division A of P.L. 113-291) and the Consolidated and Further Continuing Appropriations Act, 2015 ('Counterterrorism Partnership Fund' and Section 9016 of P.L. 113-235) provided further authority and funding guidance for the program.
825.	"Russians Strike Targets in Syria, but Not ISIS Areas," New York Times, September 30, 2015.
926.	"Russia's attack on U.S.-backed rebels in Syria puzzles, frustrates the Pentagon," Military Times, June 23, 2016.
1027.	"Syrian forces launch mass ground assault on rebel-held Aleppo," Middle East Eye, September 27, 2016.
11.	"Russia accused of war crimes in Syria at UN security council session," Guardian, September 26, 2016.
12.	U.S. Permanent Representative to the United Nations Ambassador Samantha Power, Remarks at a UN Security Council Briefing on Syria, September 25, 2016.
13.	Institute for the Study of War, "Syria Situation Report: December 8-15," 2016.
14.	Prepared with the assistance of [author name scrubbed], Specialist in Middle Eastern Affairs.
15.	Amberin Zaman, "Turkish Troops Enter Syria to Fight ISIS, May also Target U.S.-Backed Kurdish Militia," Woodrow Wilson Center, August 24, 2016.
16.	Aaron Stein and Michelle Foley, "The YPG-PKK Connection," Atlantic Council, January 26, 2016.
17.	Fehim Tastekin, "Would Putin accept Turkish buffer zone in Syria?" Al-Monitor Turkey Pulse, December 26, 2016.
18.	Thomas Gibbons-Neff, "U.S. Special Operations forces begin new role alongside Turkish troops in Syria," Washington Post, September 16, 2016; Barbara Starr and Ryan Browne, "US Special Forces join Turkish troops in Syria," CNN, September 16, 2016.
19.	Gibbons-Neff, op. cit.
20.	Department of Defense Press Briefing by Col. John Dorrian Via Teleconference from Baghdad, Iraq, November 16, 2016.
21.	Ibid.
22.	Department of Defense Press Briefing by Lt. Gen. Townsend Via Teleconference from Baghdad, Iraq, October 26, 2016.
23.	Hugh Naylor, "Assault on Raqqa to be led by Kurds," Washington Post, November 7, 2016.
24.	"Dunford, Turkish Leaders Create Long-term Plan Against ISIL in Raqqa," DoD News, November 6, 2016.
25.	Maria Abi-Habib and Nour Alakraa, "Islamic State Fortifies Post," Wall Street Journal, December 3, 2016.
26.	Remarks by Secretary Carter at the 2016 IISS Manama Dialogue, Manama, Bahrain, December 10, 2016.
27.	Remarks by Secretary of State John Kerry with Russian Foreign Minister Sergey Lavrov and UN Special Envoy Staffan de Mistura in Geneva, Switzerland, September 9, 2016.
28.	AP Exclusive: Text of Syria cease-fire deal," Associated Press, September 22, 2016.
29.	"Syria: Attack on humanitarian convoy is an attack on humanity," Press Release, International Federation of Red Cross and Red Crescent Societies," September 20, 2016.
30.	"Unrelenting Assault on Aleppo is Called Worst Yet in Syria's Civil War," New York Times, September 26, 2016.
31.	"U.S. cuts off talks with Russia on Syria cease-fire," Politico, October 3, 2016.
32.	Action Group for Syria, Final Communiqué, June 30, 2012, http://www.un.org/News/dh/infocus/Syria/FinalCommuniqueActionGroupforSyria.pdf.
33.	"Syrian President Bashar al-Assad wins third term," BBC, June 5, 2014.
34.	Vienna Communiqué on Syria, October 30, 2015, https://damascus.usembassy.gov/statedept103015en1.html.
35.	Statement of the International Syria Support Group, November 14, 2015, http://www.state.gov/r/pa/prs/ps/2015/11/249511.htm.
36.	The Kurdish PYD—which controls much of northern Syria via its YPG militia forces—has been excluded from the above negotiations, reportedly at the behest of Turkey and members of the Sunni Arab opposition.
37.	United Nations Security Council Resolution 2254, S/RES/2254 (2015).
38.	State Department Daily Press Briefing, December 20, 2016.
39.	Statement on establishing the ceasefire regime in the Syrian Arab Republic, contained in Annex I to U.N. Document S/2016/1133, December 29, 2016.
40.	"Syrian cease-fire crumbles as government forces advance around Damascus," Washington Post, January 3, 2017.
41.	Prepared by [author name scrubbed], Specialist in International Humanitarian Policy.
42.	See U.N. Office for the Coordination of Humanitarian Affairs (UNOCHA), Syrian Arab Republic: Humanitarian Needs Overview 2017. December 2016.
43.	With regard to access for relief aid workers in Syria, and U.N. cross-border and cross-line delivery of humanitarian aid to conflict affected areas without the Syrian Arab Republic Government's approval, see relevant Security Council Resolutions, including 2139 (2014), 2165 (2014), 2191 (2014), and 2258 (2015), and 2286 (2016) and Reports of the Secretary-General on the Implementation of Security Council Resolutions, the latest of which is S/2016/1057 (December 14, 2016.) See also Security Council Resolution 2328 (2016) on the humanitarian situation in the Syrian city of Aleppo, December 19, 2016; and Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, Stephen O'Brian, Statement to the Security Council on Syria, December 23, 2016.
44.	See Human Rights Council resolution S-25/1 adopted on 21 October 2016 on the deteriorating situation of human rights in the Syrian Arab Republic, and the recent situation in Aleppo; Report of the Independent International Commission of Inquiry on the Syrian Arab Republic, A/HRC/33/55, September 6, 2016.
45.	UNOCHA, "Syria Crisis Bi-Weekly Situation Report No. 19, December 12, 2016; UNOCHA, Global Humanitarian Appeal 2016 (Syria); UNOCHA, "Syrian Arab Republic: Aleppo," Situation Report No. 9, December 20, 2016.
46Department of Defense Press Briefing by Lt. Gen. Townsend Via Teleconference from Baghdad, Iraq, October 26, 2016.
28.	Department of Defense Press Briefing by Gen. Townsend via teleconference from Baghdad, Iraq, March 1, 2017.
29.	See, for example, "Syrian Opposition Figure to Deploy All-Arab Force in Raqqa Offensive," Reuters, February 1, 2017.
30.	Department of Defense Briefing by Gen. Townsend via Telephone from Baghdad, Iraq, March 28, 2017; Amberin Zaman, "Tillerson Leaves Ankara with No New Enemies—or Friends," Al-Monitor Turkey Pulse, March 30, 2017; Suleiman Al-Khalidi, "U.S.-Backed Forces Repel Islamic State Attack near Syrian Dam," Reuters, April 2, 2017. For more information, see CRS Report R43612, The Islamic State and U.S. Policy, by [author name scrubbed] and [author name scrubbed]
31.	Department of Defense Press Briefing by Pentagon Press Secretary Peter Cook in the Pentagon Briefing Room, November 10, 2016.
32.	Department of Defense Press Briefing by Col. Dorrian via teleconference from Baghdad, Iraq, February 22, 2017.
33.	Linda Anderson, "Work with Turkey, Don't Overwhelm It," U.S. News and World Report, March 9, 2017.
34.	Department of Defense Press Briefing by Gen. Townsend via teleconference from Baghdad, Iraq, March 1, 2017.
35.	Remarks by Secretary Carter at the 2016 IISS Manama Dialogue, Manama, Bahrain, December 10, 2016.
36.	"U.S. Is Sending 400 More Troops to Syria," New York Times, March 9, 2017.
37.	Department of Defense Press Briefing by Col. Dorrian via teleconference from Baghdad, Iraq, March 15, 2017.
38.	Department of Defense Briefing by Gen. Townsend via Telephone from Baghdad, Iraq, March 28, 2017.
39.	Maria Abi-Habib and Nour Alakraa, "Islamic State Fortifies Post," Wall Street Journal, December 3, 2016.
40.	Department of Defense Briefing by Gen. Townsend via Telephone from Baghdad, Iraq, March 28, 2017.
41.	"Local Forces Launch Daring Assault Behind Enemy Lines in Syria," DoD News, March 22, 2017, http://www.centcom.mil.
42.	Gen. Votel in a hearing before the Senate Armed Services Committee, March 9, 2017.
43.	"U.S. appears to root for Kurdish support in Raqqa push-Turkish sources," Reuters, March 7, 2017.
44.	"Local Forces Launch Daring Assault Behind Enemy Lines in Syria," DoD News, March 22, 2017, http://www.centcom.mil.
45.	Columb Strack, "US-Backed Militia Offensive Against Islamic State in Eastern Syria Probably Aimed at Cutting Off Mosul from Raqqah," IHS Jane's Intelligence Review, December 3, 2015.
46.	Department of Defense Briefing by Gen. Townsend via Telephone from Baghdad, Iraq, March 28, 2017.
47.	"Syrian Regime Forces to Take over Manbij, Says Russia," Hurriyet Daily News, March 3, 2017.
48.	Department of Defense Press Briefing by Col. Dorrian via teleconference from Baghdad, Iraq, March 15, 2017.
49.	Amberin Zaman, "Syrian Kurds Cede Buffer as Turkish-Backed FSA Advances on Manbij," Al-Monitor Turkey Pulse, March 2, 2017.
50.	Department of Defense Press Briefing by Col. Dorrian via teleconference from Baghdad, Iraq, March 15, 2017.
51.	Department of Defense Press Briefing by Col. Dorrian via teleconference from Baghdad, Iraq, March 15, 2017.
52.	For information on reported debates within the Trump Administration regarding the Raqqah strategy, see Dion Nissenbaum and Maria Abi-Habib, "U.S. Split on Plan to Beat ISIS in Syria," Wall Street Journal, March 10, 2017.
53.	Amberin Zaman, "Turkish Troops Enter Syria to Fight ISIS, May Also Target U.S.-Backed Kurdish Militia," Woodrow Wilson Center, August 24, 2016.
54.	Department of Defense Press Briefing by Gen. Townsend via teleconference from Baghdad, Iraq, March 1, 2017.
55.	Aaron Stein and Michelle Foley, "The YPG-PKK Connection," Atlantic Council, January 26, 2016; Amberin Zaman, "Ankara Intensifies Strikes Against YPG, Moves to Arrest PYD Leader," Al Monitor Turkey Pulse, November 22, 2016.
56.	In an April, 28, 2016, Senate hearing, Secretary of Defense Ash Carter appeared to answer "yes" to a question on whether the YPG has ties to the PKK, but he later reiterated that the YPG is not a designated terrorist organization.
57.	Stein and Foley, op. cit. One such source claims that although the PYD and PKK are officially independent, "in practice, Syrian Kurdish PKK cadres with years of service in Qandil (the organisation's northern Iraqi mountain base) dominate the YPG leadership and are the decision-makers within the self-proclaimed 'autonomous administration'" in Syria.
58.	"Turkey Can Start New Operation If Necessary as Euphrates Shield Ends: PM," Hurriyet Daily News, March 30, 2017.
59.	See Dylan Collins, "Idlib's Rebel Split: A Crossroads for Syrian Opposition," Al Jazeera English, February 2, 2017; and Aron Lund, "The Jihadi Spiral," Carnegie Middle East Center–Diwan (online), February 8, 2017.
60.	The main groups uniting under the Tahrir al Sham banner include Jabhat Fatah al Sham, the Noureddin Al Zinki Movement, Liwa al Haq (Brigade of the Right), Liwa Ansar al Din (Supporters of Religion Brigade), and Jaysh Al Sunna (Army of the Sunna).
61.	Hai'a Tahrir al Sham, "Constituents of the Tahrir al Sham Body," Infographic, Twitter, January 31, 2017.
62.	Abu Jabir Hashem al Sheikh formerly led the Ahrar al Sham coalition and is now the general commander of Tahrir al Sham. Ali al Umar (aka Abu Ammar al Taftnazi) is Ahrar al Sham's current leader.
63.	These groups reportedly include the northern Syria-based Jaysh al Mujahidin (Army of Mujahidin), Suqour al Sham (Levant Hawks), Jabhat al Shamiya (Levant Front), Tajamu Fastaqim Kama Umirt ('Stand Up as Ordered' Union), Jaysh al Islam (Army of Islam), Faylaq al Rahman (Al Rahman Corps), and Faylaq al Sham (Levant Corps).
64.	Manar Abdel Razzaq, "Ahrar Al Sham Leading Figures Join Tahrir Al Sham Committee, Fears of Adding the Latter to Lists of Terrorist Organizations" Al Quds al Arabi (London), in Arabic, January 31, 2017.
65.	Action Group for Syria, Final Communiqué, June 30, 2012, http://www.un.org/News/dh/infocus/Syria/FinalCommuniqueActionGroupforSyria.pdf.
66.	"Syrian President Bashar al-Assad Wins Third Term," BBC, June 5, 2014.
67.	State Department Daily Press Briefing, December 20, 2016.
68.	Statement on establishing the cease-fire regime in the Syrian Arab Republic, contained in Annex I to U.N. Document S/2016/1133, December 29, 2016.
69.	"Syria Peace Talks in Astana Close with No Sign of Rebels," Reuters, March 15, 2017.
70.	Prepared by [author name scrubbed], Specialist in International Humanitarian Policy.
71.	Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, Stephen O'Brien, Remarks at the 'Syria–Humanitarian Assistance and Resilience' Segment of the Ministerial-level Plenary Session of the Brussels Conference on Supporting the Future of Syria and the Region, April 5, 2017. Based on figures in the U.N. Secretary-General's March 2017 report to the Security Council, there are more than 4.05 million people living in hard-to-reach areas and more than 641,000 people living in besieged areas. Report of the Secretary-General on Implementation of Security Council resolutions 2139 (2014), 2165 (2014), 2191 (2014), 2258 (2015) and 2332 (2016), U.N. Document S/2017/244, March 22, 2017.
72.	With regard to access for relief aid workers in Syria, and U.N. cross-border and cross-line delivery of humanitarian aid to conflict affected areas without the Syrian Arab Republic Government's approval, see relevant Security Council Resolutions, including 2139 (2014), 2165 (2014), 2191 (2014), and 2258 (2015), and 2286 (2016) and Reports of the Secretary-General on the Implementation of Security Council Resolutions, the latest of which is U.N. Document S/2017/244 of March 22, 2017.
73.	See Human Rights Council resolution S-25/1 adopted on 21 October 2016 on the deteriorating situation of human rights in the Syrian Arab Republic, and the recent situation in Aleppo; Report of the Independent International Commission of Inquiry on the Syrian Arab Republic, A/HRC/33/55, September 6, 2016.
74.	Report of the Secretary-General on Implementation of Security Council resolutions 2139 (2014), 2165 (2014), 2191 (2014), 2258 (2015) and 2332 (2016), U.N. Document S/2017/244, March 22, 2017.
UNOCHA, Syrian Arab Republic: Humanitarian Needs Overview 2017., December 2016.
47.	UNOCHA, "Syrian Arab Republic: Humanitarian Snapshot," December 31, 2016. UNOCHA, "2016 Summary of Humanitarian Response Plan Monitoring Report, Syrian Arab Republic, January – June 2016." See also USAID, "Syria – Complex Emergency," Fact Sheet #5, Fiscal Year (FY) 2016, September 30, 2016 (most recent fact sheet available)76. UNOCHA, Syria Regional Refugee Response Inter-agency Information Sharing Portal, April 5, 2017. See International Organization for Migration (IOM), "Irregular Migrant, Refugee Arrivals in Europe Top One Million in 2015," December 22, 2015; and "Mediterranean Migrant Arrivals Top 363,348 in 2016; Deaths at Sea: 5, 079," January 6, 2017. Beginning in 2015, Europe was impacted by what many consider to be its worst refugee and migration crisis since World War II, as more than a million people fled conflict and poverty in neighboring regions. UNHCR has asserted that more than 85% of those arriving in Europe are from refugee-producing countries, with many from Syria and Iraq. The number of arrivals and fatalities has fluctuated, and since March 2016, in part due to EU efforts to discourage people from undertaking the journey, the number of refugees and migrants reaching Europe has decreased substantially.
4877.	Report of the Secretary-General on Implementation of Security Council resolutions 2139 (2014), 2165 (2014), 2191 (2014), 2258 (2015) and 2332 (2016), U.N. Document S/2017/244, March 22, 2017.
78.	UNHCR, "Loss of Hope and Deepening Poverty Driving Syrians to Seek Refuge in Europe," September 25, 2015.
79.	In the final tally by UNOCHA's Financial Tracking Service, the 2016 3RP was 60% funded and the HRP for Syria was 49% funded.
80.	For post-conference financial tracking, see https://2c8kkt1ykog81j8k9p47oglb-wpengine.netdna-ssl.com/wp-content/uploads/2016/11/Final-Syria-Report-Sept-16.pdf.
81.	U.N. News Center, "Donors Pledge $6 Billion to Help Support Future of War-Torn Syria at UN-Backed Conference," April 5, 2017.
82.	State Department Bureau of Population, Refugees, and Migration, U.S. Humanitarian Assistance in Response to the Syrian Crisis, April 5, 2017.
83.	The Obama Administration's FY2017 initial budget request sought $6.156 billion in global humanitarian assistance. This included $2.1 billion for Syria in Overseas Contingency Operations (OCO) funds provided through the Migration and Refugee Assistance (MRA) and International Disaster Assistance (IDA) accounts to address the humanitarian impact of this crisis and the humanitarian response in Iraq. An additional $260.4 million for MRA and $953.2 million for IDA were requested by the Obama Administration on November 10, 2016.
84.	Secretary of State Rex Tillerson, Remarks with National Security Advisor H.R. McMaster, April 6, 2017.
85.	Office of the State Department Spokesperson, "Syrian Crisis: U.S. Efforts and Assistance," August 7, 2015.
UNOCHA, "2016 Summary of Humanitarian Response Plan Monitoring Report, Syrian Arab Republic, January – June 2016."
49.	In order to help maximize efficiency, reduce duplication and ensure greater accountability, effectiveness and reach of humanitarian programming, the humanitarian community takes a whole-of-country approach in Syria.
50.	USAID, "Syria – Complex Emergency," Fact Sheet #5, Fiscal Year (FY) 2016, September 30, 2016. The Administration's FY2017 original budget request sought $6.156 billion in global humanitarian assistance. This included $2.1 billion (Syria) and $341 million (Iraq) in Overseas Contingency Operations (OCO) funds provided through the Migration and Refugee Assistance (MRA) and International Disaster Assistance (IDA) accounts to address the humanitarian impact of these crises. An additional $260.4 million for MRA and $953.2 million for IDA were requested by the Administration on November 10, 2016. In the Further Continuing and Security Assistance Appropriations Act, 2017 (P.L. 114-254), OCO funding, which is exempt from discretionary spending limits, was continued at FY2016 levels, with additional funds to counter ISIL provided in several accounts, including $300 million for MRA and $616.1 million for IDA.
51.	On June 18, Secretary of Defense Carter said, "the best way for the Syrian people for this to go would be for him to remove himself from the scene and there to be created, difficult as that will be, a new government of Syria based on the moderate opposition that we have been trying to build and support and then helping them strengthen themselves and to retake all of Syrian territory. That would be a desirable path if he did remove -- was removed from the scene or removed himself from the scene." Secretary of Defense Ashton Carter, Testimony before the House Armed Services Committee, June 17, 2015.
52.	Secretary of Defense Ashton Carter, Testimony before the Senate Armed Services Committee, July 7, 2015.
53.	Ibid.
54.	Secretary of State John Kerry before the Senate Appropriations Subcommittee on State, Foreign Operations and Related Programs, February 24, 2016.
55.	Secretary of Defense Ashton Carter before the Senate Appropriations Subcommittee on Defense, May 6, 2015.
56.	White House Office of the Press Secretary, Press Conference by the President, December 16, 2016.
57.	The President said, "our attitude towards Asad continues to be that you know, through his actions, through using chemical weapons on his own people, dropping barrel bombs that killed innocent children that he—he has foregone legitimacy. But when it comes to our policy and the coalition that we're putting together, our focus specifically is on ISIL. It's narrowly on ISIL." President Obama interview with NBC News Meet the Press, September 6, 2014.
58.	For a selection of critical perspectives see, Michael Eisenstadt, "The War Against ISIL: In Search of a Viable Strategy, Washington Institute for Near East Policy, June 15, 2015; Frederic Hof, Trouble in Train-and-Equip Land, the Atlantic Council, July 9, 2015; Michael Rubin, "U.S. Policy towards the Islamic State after its Seizure of Ramadi and Palmyra," American Enterprise Institute, June 3, 2015.
59.	For one discussion of this issue, see Michael Weiss, "Exclusive: Syrian Rebels Backing Out of U.S. Fight Vs. ISIS," The Daily Beast, May 31, 2015.
60.	Testimony of Secretary of State John Kerry, Secretary of Defense Ashton Carter, and Chairman of the Joint Chiefs of Staff General Martin Dempsey before the Senate Foreign Relations Committee. March 11, 2015; and Briefing by Secretary of Defense Ashton Carter and CJCS General Martin E. Dempsey, May 7, 2015.
61.	Department of Defense Press Briefing by Pentagon Press Secretary Peter Cook in the Pentagon Briefing Room, June 6, 2016.
62.	"Rivals of ISIS Attack U.S.-Backed Syrian Rebel Group," New York Times, July 31, 2015; "Islamic State hits U.S.-backed Syrian rebel base near Iraq border," Reuters, August 7, 2016; "Russia's attack on U.S.-backed rebels in Syria puzzles, frustrates the Pentagon," Military Times, June 23, 2016.
63.	Ibid.
64.	"In Syria, militias armed by the Pentagon fight those armed by the CIA," Los Angeles Times, March 27, 2016.
65.	"Syria: al-Qaeda Nusra Front shows off huge cache of US weapons seized from moderate Harakat Hazm rebels," International Business Tribune," March 4, 2015; "The Islamic State Just Got Their Hands on More U.S. Weapons," Foreign Policy, June 29, 2016.
66.	"C.I.A. Arms for Syrian Rebels Supplied Black Market, Officials Say," New York Times, June 26, 2016.
67.	Office of the State Department Spokesperson, "Syrian Crisis: U.S. Efforts and Assistance," August 7, 2015.
68.	Opposition infighting in late 2013 led to the capture of some nonlethal U.S. assistance by Islamist groups. U.S. officials subsequently revisited some delivery and monitoring mechanisms and worked to improve the reliability and security of delivery channels. Dasha Afanasieva and Humeyra Pamuk, "U.S., Britain suspend aid to north Syria after Islamists seize weapons store," Reuters, December 11, 2013.
6987.	Syria Humanitarian Assistance, Government Accountability Office, July 2016.
7088.	For more on background on the origins of this program and related legislation, see CRS Report R43727, Train and Equip Program for Syria: Authorities, Funding, and Issues for Congress, by [author name scrubbed] and [author name scrubbed].
7189.	The program came under intense scrutiny in the wake of August and September 2015 reports that some of the small number of U.S. trainees that had completed the program quit and others may have turned over equipment and weaponry to Jabhat al Nusra, the Al Qaeda affiliate that controls much of Idlib Province in northwest Syria. As of October 2015, U.S. officials reported that the program had produced 124 graduates, 70 of whom had returned to Syria in September 2015. Of the other 54, U.S. CENTCOM Commander General Lloyd Austin told the Senate Armed Services Committee that "four or five" then remained "in the fight" against the Islamic State in Syria, after having come under Jabhat al Nusra attack in July 2015.
7290.	"Explanatory statement" accompanying the enrolled version of P.L. 114-113/H.R. 2029, as published by the House Rules Committee.
7391.	Department of Defense, Prior Approval Reprogramming Action FY16-11PA, March 17, 2016.
7492.	Department of Defense Fiscal Year 2017 Budget Request for Overseas Contingency Operations Syria Train and Equip Fund, February 2016.
7593.	In June 2014, the House adopted H.Amdt. 914 to H.R. 4870, which provided that "None of the funds made available by this Act may be obligated or expended to transfer man-portable air defense systems (MANPADS) to any entity in Syria." It was included in the House engrossed version of the bill as Section 10010.
7694.	H.Amdt. 487 to H.R. 2685.
7795.	See Amendment 81 in H.Rept. 114-571, adopted as part of en bloc amendment H.Amdt. 1046 to H.R. 4909. If enacted, the amendment would provide that, "none of the funds authorized to be appropriated by this Act or otherwise made available for the Department of Defense for fiscal year 2017 may be obligated or expended to transfer or facilitate the transfer of man-portable air defense systems (MANPADS) to any entity in Syria."
7896.	Jonathan Landay and Arshad Mohammed, "Gulf may arm rebels now Syria truce is dead - U.S. officials," September 27, 2016.
7997.	State Department press briefing by Deputy Spokesperson Mark C. Toner, September 27, 2016.
8098.	"Syrian Rebels Get Missiles," Wall Street Journal, October 17, 2012; "Officials: Syrian rebels' arsenal includes up to 40 antiaircraft missile systems," Washington Post, November 28, 2012; "As Russian planes bombard Syrian rebels, debate over anti-aircraft missiles returns," Los Angeles Times, May 1, 2016.
8199.	Secretary Hagel said, "it was June of this year that the president made the decision to support lethal assistance to the opposition. As you all know, we have been very supportive with hundreds of millions of dollars of nonlethal assistance. The vetting process that Secretary Kerry noted has been significant, but—I'll ask General Dempsey if he wants to add anything—but we, the Department of Defense, have not been directly involved in this. This is, as you know, a covert action. And, as Secretary Kerry noted, probably to [go] into much more detail would—would require a closed or classified hearing."
82100.	Adam Entous, Julian E. Barnes and Siobhan Gorman, "U.S. Begins Shipping Arms for Syrian Rebels," Wall Street Journal, June 26, 2013; Greg Miller, "CIA ramping up covert training program for moderate Syrian rebels," Washington Post, October 2, 2013; Greg Miller and Karen DeYoung, "Secret CIA effort in Syria faces large funding cut," Washington Post, June 12, 2015.
83101.	Miller and DeYoung, "Secret CIA effort in Syria faces large funding cut," Washington Post, June 12, 2015.
84102.	Adam Entous, "U.S. Sees Russian Drive Against CIA-Backed Rebels in Syria," Wall Street Journal, October 5, 2015.
85103.	See Harakat Hazm YouTube Channel, April 15, 2014, at http://www.youtube.com/watch?v=5x5Q4aTGvu0.
86104.	Ben Hubbard, "Syrian Election Announced; Rebels Report New Weapons," New York Times, April 21, 2014.
87105.	Liz Sly, "Syrian rebels who received first U.S. missiles of war see shipment as 'an important first step,'" Washington Post, April 27, 2014.
88106.	Tom Bowman and Alice Fordham, "CIA Is Quietly Ramping Up Aid To Syrian Rebels, Sources Say," National Public Radio (Online), April 23, 2014
89107.	Transcript of Background Briefing on Syria by Senior Administration Official, U.S. State Department, May 5, 2014.
90108.	Section 3(a)(2) of the Arms Export Control Act (22 U.S.C. 2753 (a)(2)) applies obligations, restrictions, and possible penalties for misuse of U.S.-origin equipment to any retransfer by foreign recipients of U.S.-supplied defense articles, defense services, and related technical data to another nation. If such a retransfer occurred in the absence of prior U.S. approval, then the nation making such a transfer could be determined to be in violation of its agreement with the United States not to take such an action without prior consent from the U.S. government.
91109.	See Tajammu al Izza YouTube Channel, October 1, 2015, at https://www.youtube.com/watch?v=AqGuUbVtGl8.
92110.	See Ansar al Islam Front YouTube Channel, August 10, 2014, at http://www.youtube.com/watch?v=k9pxIFUKEZg and http://www.youtube.com/watch?v=1QclDMPQkPw.
93111.	Umberto Bacchi, "Syria: al-Qaeda Nusra Front shows off huge cache of US weapons seized from moderate Harakat Hazm rebels," Shows Off Huge Cache of US Weapons Seized from Moderate Harakat Hazm Rebels," International Business Times, March 4, 2015; Michael Smallwood, "Captured TOW 2A missiles employedMissiles Employed in Syria," Armament Research Services, 2015.
94112.	OSC Report TRR2015062676424947, "ISIL Deploys Apparent TOW Missile System Against Regime Forces in Al Hasakah,," June 26, 2015.
95113.	"C.I.A. Arms for Syrian Rebels Supplied Black Market, Officials Say," New York Times, June 26, 2016.
96114.	Prepared by Mary Beth Nikitin, Specialist in Nonproliferation.
97.	Most recently: Statement from the OPCW Director General on Allegations of Chemical Weapons Use in Uqayribat, Hama Governate, Syria, OPCW Press Release, December 13, 2016.
98115.	The Syrian government in 2013 joined the Chemical Weapons Convention (CWC), which bans the use of any toxic chemicals in warfare and requires—along with U.N. Security Council resolutions—that Syria destroy all of its chemical weapons stocks and production facilities under international supervision.
116.	"Trump Orders Missile Attack in Retaliation for Syrian Chemical Strikes," DoD News, April 6, 2017.
117.	Statement by President Trump on Syria, April 6, 2017.
118.	Rex Tillerson, Secretary of State, Remarks with National Security Advior H.R. McMaster, April 6, 2017.
119.	World Health Organization, "WHO Alarmed by Use of Highly Toxic Chemicals in Syria," press release, April 5, 2017.
120.	Some victims of the attack were moved to Turkey for treatment, where experts could assess their symptoms and likely causes. Louisa Loveluck, "Deadly Nerve Agent Sarin Used in Deadly Attack," Washington Post, April 6, 2017.
121.	White House Office of the Press Secretary, Government Assessment of the Syrian Government's Use of Chemical Weapons on August 21, 2013, August 30, 2013.
122.	Chapter VII of the U.N. Charter authorizes the use of punitive measures such as sanctions or military force.
123.	Organization for the Prohibition of Chemical Weapons, "Destruction of Syrian Chemical Weapons Completed," press release, January 4, 2016,
124.	"Note by the Director General: Progress in the Elimination of the Syrian Chemical Weapons Programme," EC-83/DG.6, August 22, 2016, https://www.opcw.org/fileadmin/OPCW/EC/83/en/ec83dg06_e_.pdf. As of August 22, 2016, the OPCW reported that 24 of the 27 declared chemical weapons production facilities (CWPFs) had been destroyed. The "poor security situation" prevents destruction of the remaining aircraft hangar and two stationary above-ground facilities. The OPCW said that Syrian government is cooperating on this matter.
125.	Ibid.
126.	Julian E. Barnes and Maria Abi-Habib, "Syrian Attack Defies 2013 Chemical-Weapons Deal," Wall Street Journal, April 6, 2017.
Reports by U.N. Member States have been made via confidential correspondence, such as letters containing allegations described generally in the December 2013 final report of U.N. Mission to Investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic (the U.N. Mission). See U.N. Mission, Final Report, December 12, 2013, pp. 2-6.
99128.	The U.N. Mission to investigate Allegations of the Use of Chemical Weapons in the Syrian Arab Republic released its report on September 16, 2013, concluding that surface-to-surface rockets containing the chemical weapons nerve agent sarin were used in the Ghouta area of Damascus against civilians on a "relatively large scale." The 2013 U.N. investigative mission was not tasked with assigning culpability for the attacks.
100129.	See U.N. Mission, Final Report, December 12, 2013; and, OPCW Fact-Finding Mission (FFM) in Syria, Final Report, December 2015, attached to "Letter dated 27 January 2016 from the Secretary-General addressed to the President of the Security Council," S/2016/85, January 28, 2016, http://www.un.org/en/ga/search/view_doc.asp?symbol=S/2016/85.
101130.	Arms Control Association, "Timeline of Chemical Weapons Attacks in Syria: 2012-2017," fact sheet, 2017, https://www.armscontrol.org/factsheets/Timeline-of-Syrian-Chemical-Weapons-Activity.	Government Assessment of the Syrian Government's Use of Chemical Weapons on August 21, 2013, White House Office of the Press Secretary, August 30, 2013.
102.	Chapter VII of the UN Charter authorizes the use of punitive measures such as sanctions or military force.
103.	"Destruction of Syrian chemical weapons completed," OPCW Press Release, January 4, 2016, https://www.opcw.org/news/article/destruction-of-syrian-chemical-weapons-completed/.
104.	"Note by the Director General: Progress in the Elimination of the Syrian Chemical Weapons Programme," EC-83/DG.6, August 22, 2016. https://www.opcw.org/fileadmin/OPCW/EC/83/en/ec83dg06_e_.pdf. As of August 22, 2016, the OPCW reported that 24 of the 27 declared chemical weapons production facilities (CWPFs) had been destroyed. The "poor security situation" prevents destruction of the remaining aircraft hangar and two stationary above-ground facilities. The OPCW said that Syrian government is cooperating on this matter.
105.	Ibid.
106.	Resolution 2235 required that the U.N. Secretary-General, in coordination with the OPCW Director-General, submit within 20 days recommendations for its approval on the establishment of a Joint Investigative Mechanism "to identify to the greatest extent feasible individuals, entities, groups, or governments who were perpetrators, organisers (sic)[sic], sponsors or otherwise involved in the use of chemicals as weapons, including chlorine or any other toxic chemical, in the Syrian Arab Republic where the OPCW FFM determines or has determined that a specific incident in the Syrian Arab Republic involved or likely involved the use of chemicals as weapons, including chlorine or any other toxic chemical… ."
107132.	Letter dated 24 August 2016 from the Leadership Panel of the Organization for the Prohibition of Chemical Weapons-United Nations Joint Investigative Mechanism addressed to the Secretary-General, S/2016/738; Letter dated 21 October 2016 from the Leadership Panel of the Organization for the Prohibition of Chemical Weapons-United Nations Joint Investigative Mechanism addressed to the Secretary-General, S/2016/888.
108133.	The JIM report states that OPCW experts were able to identify that the sulfur mustard was produced by the Islamic State because of the way it was produced, which was different from Syrian government stocks. "The OPCW confirmed that the sulfur mustard from the Syrian Arab Republic did not contain impurities such as polysulphides, meaning that a different process was used by the Government. The OPCW also reported that the sulfur mustard used by ISIL in northern Iraq on several occasions n 2015 and 2016 was produced through the Levinstein process." Ibid, p.97 97.
109134.	http://www.whatsinblue.org/2016/11/syria-renewal-of-the-un-opcw-joint-investigative-mechanism.php.
110135.	Mark Toner, Deputy State Department Spokesman, "The Fourth Report of the Joint Investigative Mechanism," Press Statement, October 28, 2016. https://www.state.gov/r/pa/prs/ps/20162016/10/263771.htm.
111136.	On August 7, the Permanent Representative of Syria to the United Nations Dr. Bashar Jaafari told the United Nations Security Council that, "the Syrian Government and the Syrian army have never used chemical weapons, and never will. Contrariwise, Syria's army and its civilians have been targeted with toxic chemicals and chemical weapons, including chlorine gas, by armed terrorist groups, such as Daesh [Arabic acronym for ISIL] and the Al-Nusra Front, in many parts of Syria… ." He accused unspecified investigation missions of having "based their work on false, fabricated statements made by parties well known to all. Those missions have carried out partial and biased investigations — outside Syria — —outside Syria—without a modicum of coordination with the Syrian authorities." (U.N. Document S/PV.7501.) The U.N. and OPCW investigative missions have worked inside Syria with the permission of the Syrian government. In 2011, the U.N. Human Rights Council established an Independent International Commission of Inquiry on the Syrian Arab Republic that has reported extensively on the conflict, including on alleged chemical attacks. The Commission uses a "reasonable grounds to believe" standard of evidence and relies on first-hand accounts from Syrians now in neighboring countries, remote interviews, and other publicly available information.
112137.	"Syria Draft Resolution Imposing Sanctions Regarding the Use and Production of Chemical Weapons," What's In Blue, February 25, 2017, http://www.whatsinblue.org/2017/02/syria-draft-resolution-imposing-sanctions-regarding-the-use-and-production-of-chemical-weapons.php.	"U.S. Tests Show Mustard Gas Traces in Islamic State Attack," The Washington Post, August 21, 2015.
113139.	"IS likely used chemical weapons in Syria, Iraq; could use them elsewhere, OPCW head says," Slovenia Press Agency,Slovenia Press Agency, "IS Likely Used Chemical Weapons in Syria, Iraq; Could Use Them Elsewhere, OPCW Head Says," May 11, 2016, https://www.opcw.org/is-likely-used-chemical-weapons-in-syria-iraq-could-use-them-elsewhere-opcw-head-says-interview/.
114140.	"U.S.: shell that hit Iraqi base contained sulfur-mustard agent," The Shell That Hit Iraqi Base Contained Sulfur-Mustard Agent," Associated Press, September 22, 2016; "U.S. troops brace for more mustard attacksTroops Brace for More Mustard Attacks," Military Times, September 27, 2016.
115.	In a March 1980 intelligence product, the Central Intelligence Agency described the then-prevailing dynamic among members of the regime and military in relation to the Islamist upheaval as follows: "President [Hafiz al] Assad has committed his minority Alawite government to a risky course with his reported decision to use the military more freely to crush civil unrest in Syrian cities. This may intimidate his domestic opponents in the short run, but unless Assad is able to reestablish order quickly, it will also further erode his domestic support and could eventually bring about his ouster. By committing the military, Assad is playing his last major card to keep his regime in power. Army discipline may well collapse in the face of widespread riots. This could lead to a bloody war between Sunni Muslim and Alawite units. The Alawites, however, may choose to topple Assad before such turmoil develops in order to keep their position secure." Central Intelligence Agency Directorate of Intelligence, "SPECIAL ANALYSIS - SYRIA: Assad's Prospects," National Intelligence Daily, March 17, 1980; in U.S. State Department, Foreign Relations of the United States (FRUS) 1977–1980, Volume IX, Arab-Israeli Dispute, August 1978– December 1980, pp. 1102-4141. U.S. Permanent Representative to the United Nations Ambassador Nikki Haley, Remarks at a U.N. Security Council Meeting on the Situation in Syria, April 7, 2017.
116142.	See Chris Zambelis, "Syria's Sunnis and the Regime's Resilience," U.S. Military Academy Combatting Terrorism Center (CTC), CTC Sentinel, May 28, 2015Secretary of State Rex Tillerson, Remarks with National Security Advisor H.R. McMaster, April 6, 2017.