December 3, 2024
Two coalitions of armed groups opposed to Syrian President Bashar Al Asad (alt. Assad) made rapid and unexpected advances in late November 2024, taking Aleppo, the country’s second largest city, and other parts of northwestern Syria (Figure 1). Both coalitions feature anti-Asad forces, but may have differing objectives with different implications for U.S. policy. Forces led by the U.S.-designated Foreign Terrorist Organization (FTO) Hay’at Tahrir al Sham (HTS) represent the most formidable remainder of Syria’s armed Islamist opposition, and their advance on Aleppo and points south threatens the Asad regime’s control of key areas. The Turkey-backed Syrian National Army (SNA) coalition has long been active north of Aleppo, and has renewed clashes with the U.S.-backed, Kurdish-led Syrian Democratic Forces (SDF), the key U.S. counterterrorism partner against remnants of the Islamic State (IS/ISIS) that once dominated parts of Syria and Iraq. (Available CRS products provide a brief history of the war in Syria and discuss U.S. policy.)
Both anti-Asad coalitions’ recent gains and the government’s retreats represent the largest territorial changes in Syria since 2020. The anti-Asad forces’ ability to hold new territory, govern effectively, and avoid infighting remain uncertain. The Syrian government, supported by Russia and Iran, has launched counterattacks, including airstrikes. Threats to Russian facilities or personnel in Syria could prompt more forceful intervention. Prolonged conflict could place additional strains on U.S. adversaries and partners, invite deeper foreign involvement, intensify humanitarian needs, and empower armed Islamists.
International actors, some of which are militarily active in Syria, have reiterated longstanding policy positions: Iran and Russia reaffirmed their support for Asad, and Turkey called on Asad to negotiate with his opponents. The United States, France, Germany, and the United Kingdom called for de-escalation and civilian protection, with U.S. officials calling for a political solution, in line with UN Security Council Resolution 2254. Iraq expressed support for Syria’s security, while the United Arab Emirates expressed solidarity with Syria and called for a peaceful resolution.
Approximately 900 U.S. military personnel remain deployed in eastern and southern Syria, conducting counterterrorism missions against IS remnants and supporting the SDF’s detention of more than 9,000 IS prisoners and administration of camps for more than 40,000 individuals from formerly IS-held areas.
Counterterrorism and U.S. Partners. While HTS has distanced itself from Al Qaeda (AQ), with whom it previously affiliated, and opposes the Islamic State, HTS remains “a designated terrorist organization.” U.S. National Security Adviser Jake Sullivan has noted “real concerns” about HTS objectives. Since August 2024, U.S. forces have continued their years-long targeting of AQ-linked, ex-HTS splinter group Hurras al Din in northwestern Syria.
Figure 1. Syria: Areas of Influence
As of December 3, 2024
Source: CRS using Janes Conflict Monitor data, Lead Inspector General reporting, and selected media reports. Notes: All areas approximate and subject to change.
Threats to SDF-aligned communities from HTS, SNA, or pro-Asad forces could divert SDF resources from counter-IS operations. The Turkish government seeks to counter the SDF because of links Kurdish SDF elements have with the Kurdistan Workers’ Party (PKK, another FTO). In October 2024, U.S. officials reported that attacks on the SDF by Iran-backed tribal factions and the Turkish military allowed more freedom of movement to IS fighters, contributing to their local resurgence. On December 1, the SDF-affiliated Autonomous Administration of North and East Syria (AANES) declared a general mobilization, while fighting displaced Kurdish civilians and forces eastward.
Regional Dynamics and the U.S. Presence in Syria. U.S. forces are distant from the HTS offensive but Sullivan has said they are “still under a threat from Iran and the Shia backed militia groups in Iraq and Syria.” U.S. forces have struck militia facilities in Syria linked to Iran more frequently since October 2024, and Iran-backed Iraqi or Syrian militia groups may redouble their support to Asad. Diversion of pro-Asad forces from central Syria could provide IS remnants with opportunities to regroup. Syria’s importance to Iran may have deepened since Iran and its FTO ally Lebanese Hezbollah have suffered setbacks in confrontations with Israel.
The executive branch and Congress may reevaluate the U.S. presence in Syria in light of recent developments. In 2019, then-President Trump directed a partial U.S. troop withdrawal from Syria, resulting in territorial shifts among SDF, Turkish, Syrian, Russian, and Iranian forces. Current policy foresees winding down counter-IS operations in Iraq in 2025, while continuing Iraq-based counter-IS operations in Syria into 2026. U.S. withdrawals from Syria or others’ offensives against the SDF could prompt further territorial changes.
Syria and the 118th Congress
Unfolding developments may influence pending legislative decisions on Syria-related proposals. The Senate version of the 2025 National Defense Authorization Act (NDAA, Section 1223 of S. 4638) would require the Secretary of Defense to certify the capability of U.S.-backed Syrian forces before reducing troop levels in northeast Syria below 400 personnel. Unlike a comparable provision enacted in connection with Afghanistan in the 2021 NDAA, it would not include a presidential waiver. It also would remove ‘notice and wait’ requirements for Syria train and equip funding and raise construction and repair project cost ceilings. Both the Senate and House (H.R. 8070) versions would extend train and equip authority through December 2025.
Congress also may address the December 20, 2024 sunset of the Caesar Syria Civilian Protection Act of 2019 (22 U.S.C. §8791 note). In February 2024, the House passed the Assad Regime Anti-Normalization Act of 2023 (H.R. 3202) which would amend and extend Caesar Act provisions through 2032, prohibit funds for recognizing Asad’s government, and require a strategy to counter recognition by other governments. Senate proposals differ on amendments and extension through 2028 (S. 5095) or 2032 (S. 2935). U.S. and Arab officials reportedly have discussed removing some sanctions on Asad to encourage him to distance Syria from Iran.
The House passed a State Department and Foreign Operations appropriations bill for 2025 (H.R. 8771) that would prohibit the use of funds in Asad-controlled areas. The Senate proposal (S. 4797) lacks such restrictions. Counterterrorism restrictions on the use of U.S. funds may limit U.S. options in some areas outside Asad’s control.
OutAuthor Information
Christopher M. Blanchard Specialist in Middle Eastern Affairs
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