Turkey in Syria: Key Issues for U.S. Policy

Key Chapter Title List

1. Turkey's Relationship with HTS
2. HTS and Other Relevant Parties in the Syrian Transitional Government
3. Renewed Conflict Between Turkey/Syrian National Army and Syrian Democratic Forces, and U.S. Policy Concerns
4. October 2019 Case: Turkey-led Invasion and U.S. Sanctions
5. Potential Congressional Considerations Regarding Sanctions or Other Measures
6. Broader U.S. Priorities in Syria

Document Introduction

Following the collapse of the Bashar al-Assad regime in December 2024, Turkey has become the most influential external actor in Syria, dealing a significant blow to the regime's primary external protectors, Russia and Iran. Turkey maintains a complex and multifaceted relationship with Hay'at Tahrir al-Sham (HTS), the U.S.-designated Foreign Terrorist Organization that played a leading role in overthrowing Assad in late 2024. Simultaneously, Turkey directly supports the Syrian National Army (SNA) coalition, which helped Ankara seize and maintain control over large parts of northern Syria from the Kurdish-led, U.S.-backed Syrian Democratic Forces (SDF), with whom it remains in ongoing conflict.

The Turkish government opposes U.S. support for the SDF and seeks to weaken the dominant People's Protection Units (YPG) within it, citing the YPG's links to the Kurdistan Workers' Party (PKK), a Foreign Terrorist Organization that has waged a decades-long insurgency against Turkish authorities. Turkey's protection of Idlib province has allowed its de facto ruler, HTS, to develop various military and political capabilities. Some reports suggest Turkey may have also provided drones and logistical support to HTS. A long-standing pillar of Turkish policy is to prevent further refugee influx into Turkey, which currently hosts over 3 million of the nearly 5 million Syrian refugees in the region.

In the post-Assad era, a new SNA offensive against the SDF has become one of the most critical recent issues in U.S.-Turkey relations. The conflict between the SNA and SDF has heightened U.S.-Turkey tensions, as the SDF has been the primary U.S. ground force partner in the fight against the Islamic State (IS/ISIS). Turkey and the SNA conducted three major military operations in 2016, 2018, and 2019 in response to the YPG's successive control over much of Syria's northern border region in the mid-2010s, replacing YPG rule in those areas with Turkish-backed Syrian armed groups.

Senior Biden administration officials have engaged with Turkish and SDF-related parties in an attempt to prevent further escalation of conflict, which could undermine U.S. military support for the SDF's efforts against remaining ISIS elements and its management of detention facilities and camps holding ISIS-affiliated individuals. During fighting in December 2024, the SNA, with Turkish air support, captured the towns of Tal Rifaat and Manbij from the SDF along key transportation routes, while tensions escalated among all parties in the Kobani region.

In October 2019, following former U.S. President Trump's order to withdraw U.S. troops from northern Syria, Turkey launched a ground invasion into areas then controlled by U.S.-backed SDF/YPG forces. The Trump administration imposed sanctions on Turkey for nine days before lifting them as part of a U.S.-Turkey ceasefire agreement. The fall of Assad and the concentration of Russian forces at bases in western Syria appear to have removed potential constraints on possible conflict between Turkish/SNA and SDF/YPG forces.

Congress may evaluate options such as sanctions on Turkey, arms sales, foreign assistance, and authorizations or appropriations related to U.S. military operations. Considerations may include expectations that President-elect Trump might order a withdrawal, HTS's stance on Kurdish rights, the feasibility of various parties assuming counterterrorism responsibilities, and broader U.S. priorities in Syria.