Syrian Democratic Forces

The Syrian Democratic Forces (SDF) were a multi-ethnic armed alliance formed in October 2015 during the Syrian civil war. Kurdish units formed its core, while Arab, Assyrian and other local forces joined. The alliance became the principal ground partner of the United States-led coalition against the Islamic State in Syria and captured territory from the group’s self-proclaimed caliphate.

The SDF operated in northeastern Syria alongside the Democratic Autonomous Administration of North and East Syria, a civilian administration known for its Kurdish-led political model. The force included the People's Protection Units and Women's Protection Units, as well as Arab tribal groups and Christian formations. It was supported by the United States with training, equipment and air power, but its ties to Kurdish organizations created tension with Turkey.

After Bashar al-Assad’s government fell in December 2024, the SDF agreed to integrate into Syria’s state institutions. The agreement stalled and fighting resumed in January 2026, when the transitional government launched an offensive in northeastern Syria. A ceasefire and integration agreement transferred key territory and resources to Damascus. On 25 August 2026, commander Mazloum Abdi declared the SDF dissolved after its military, security and administrative institutions completed integration into the Syrian state.

Establishment and composition

The SDF’s formation was announced in October 2015 during the Syrian civil war in al-Hasakah. It built on earlier cooperation between the People's Protection Units and several local armed groups. The alliance included the Syriac Military Council, the al-Sanadid Forces of the Shammar tribe, Liwa Thuwwar al-Raqqa and other factions. It described itself as a national force open to all communities in Syria.

The alliance grew from military cooperation during the fight against the Islamic State. The YPG and YPJ had defended Kurdish areas, including Kobani, while Arab factions joined operations to recapture towns such as Tell Abyad and Raqqa. The SDF provided a framework for these groups to coordinate operations and receive coalition support. It was not a conventional national army with a single ethnic or political base.

Kurdish units made up the most cohesive part of the SDF and provided much of its senior command. Arab members became increasingly numerous as the force advanced into areas with Arab majorities. Assyrian and other minority formations joined in local areas. The diversity of the alliance was politically significant but did not eliminate disputes over representation, recruitment and control.

The SDF was linked to the broader political project of democratic confederalism promoted by the Democratic Union Party (PYD). This model emphasized local councils, gender equality and ethnic pluralism. Critics argued that the PYD and YPG dominated the administration and restricted rivals. The SDF’s military structure and the civilian authority were closely connected, though they were not formally identical institutions.

Estimates of SDF strength changed over time and differed according to whether they counted full-time combatants, local security units or allied formations. The alliance expanded during the campaign against the Islamic State and incorporated new forces in areas it captured. It also included women’s units and local defense forces. No single public figure fully represented its changing composition.

Campaign against the Islamic State

The SDF’s earliest major operation was in northern Syria against Islamic State forces. In 2015, it took Tell Abyad and linked areas previously separated by the group’s control. The victory disrupted a supply route between Turkey and Raqqa. Coalition aircraft provided support, and the SDF’s ground forces advanced with Arab allies from the Euphrates region.

In 2016, the SDF captured Manbij after a prolonged campaign. The operation included Kurdish and Arab units and received coalition air support. The advance threatened the Islamic State’s remaining routes toward the Turkish border. Turkey opposed the growth of Kurdish forces near its frontier and conducted military operations to prevent them from linking their territories.

The SDF launched its campaign to capture Raqqa in 2016, with the operation intensifying in 2017. Raqqa had served as the Islamic State’s de facto capital in Syria. The battle involved urban combat, coalition airstrikes and heavy destruction. Thousands of civilians were displaced, and many were killed or injured. The SDF announced the city’s capture in October 2017, after months of fighting.

The alliance then advanced into Deir ez-Zor province and the Euphrates Valley. It captured oil fields and towns and worked with Arab tribal formations. The campaign ended with the capture of Baghouz in March 2019, the last major territorial enclave held by the Islamic State in Syria. The group’s territorial rule ended, but its insurgent cells remained active.

The SDF’s defeat of the Islamic State made it a key security partner for the United States. Its forces guarded detention facilities and camps holding Islamic State fighters and their families. The task placed a heavy burden on local authorities and created risks of prison breaks and radicalization. The SDF called for foreign governments to repatriate their citizens, while many states hesitated to do so.

The alliance’s battlefield success depended on coalition air support, intelligence and equipment as well as local fighters. The United States trained units and provided weapons, while coalition aircraft struck Islamic State positions. The partnership was described by Washington as tactical and focused on counterterrorism. The SDF sought broader political recognition and security guarantees, goals that the United States did not fully endorse.

Political administration and governance

The SDF operated in areas administered by the Democratic Autonomous Administration of North and East Syria. The administration developed councils, local departments and security institutions. It promoted a system of local representation and gender equality, including co-chair arrangements in some bodies. Critics questioned the freedom of political competition and accused the PYD of suppressing Kurdish opposition.

In Arab-majority areas, SDF units included local Arab formations and councils. The transition from Islamic State rule to the autonomous administration was uneven. Local leaders negotiated over security, education and resource control. In Deir ez-Zor, protests and clashes reflected frustration over governance, service provision and the role of Kurdish-led authorities.

The SDF and administration controlled oil and gas fields, border crossings and agricultural areas. These resources helped fund local institutions but also became points of dispute with Damascus and other Syrian actors. The administration sought recognition of a decentralized political system within a future Syria, while the central government rejected any arrangement that weakened state sovereignty.

Women's participation was a prominent feature of the SDF. The YPJ became internationally known for its role in combat against the Islamic State. The administration promoted women’s councils and social reforms. Conservative communities sometimes opposed these policies, while advocates viewed them as a major change in a patriarchal political environment.

Security forces associated with the administration arrested political opponents and critics. Human rights groups reported arbitrary detention, torture and restrictions on expression. Authorities said arrests targeted Islamic State members and security threats. Independent monitoring was limited, and the distinction between military security operations and political repression was contested.

United States partnership and regional conflict

The United States-led coalition partnered with the SDF from 2015 to defeat the Islamic State. American personnel trained and advised SDF units and coordinated air support. The partnership strengthened the alliance and allowed it to capture extensive territory. It also created a long-term American presence in eastern Syria and a strategic disagreement with Turkey, a NATO ally.

Turkey considers the YPG closely linked to the Kurdistan Workers' Party (PKK), which Turkey, the United States and the European Union designate as a terrorist organization. The United States distinguished the SDF from the PKK and worked with it against the Islamic State. Turkey’s opposition led to military operations in northern Syria and repeated threats against SDF-controlled areas.

In 2018, Turkey launched an operation against Afrin, which had been controlled by Kurdish forces. The SDF withdrew, and Turkey-backed factions took control. In 2019, a United States decision to withdraw forces from parts of northern Syria preceded a Turkish incursion. The SDF reached an arrangement with the Syrian government and Russia to deploy forces near the border, demonstrating the fragility of its partnership with Washington.

The SDF also faced conflict with the Syrian government, Iranian-backed militias and local armed groups. The parties sometimes negotiated ceasefires and security arrangements, while competing over territory and resources. The force’s relationship with Damascus shifted between confrontation and talks about integration.

Human rights allegations

Human rights organizations reported violations by SDF units and the autonomous administration. Allegations included arbitrary detention, torture, forced displacement, property destruction and restrictions on political activity. In some cases, SDF officials opened investigations or disciplined members. Accountability mechanisms remained limited and were criticized for a lack of transparency.

Amnesty International reported demolitions and forced displacement in northern Syria in 2015, alleging that Kurdish forces had unlawfully destroyed homes in some villages. The SDF and affiliated authorities disputed allegations of systematic ethnic cleansing and said some demolitions were related to military necessity or Islamic State threats. Later United Nations reporting did not find evidence for some claims of a coordinated demographic campaign, but abuses and displacement remained documented concerns.

Child recruitment was another serious issue. Human Rights Watch reported that Kurdish forces recruited children despite promises to demobilize them. The SDF later signed a United Nations action plan to end and prevent the recruitment and use of children. Monitoring groups continued to report cases, and the alliance announced measures to remove underage recruits from its ranks.

Reports also described detention conditions in camps and prisons holding Islamic State members and their families. Amnesty International documented deaths, torture and other violations in detention after the group’s territorial defeat. SDF authorities faced a major security burden but remained responsible for protecting detainees and civilians under their control.

These allegations do not erase the SDF’s role in defeating the Islamic State, just as that role does not excuse abuses. Each claim requires careful attribution and should be distinguished from unsupported political accusations. Independent access to detention sites and transparent investigations are important to establish facts.

Integration into the Syrian state

After Assad’s fall in December 2024, SDF commander Mazloum Abdi met with Syrian president Ahmed al-Sharaa on 10 March 2025. Abdi announced an agreement to integrate SDF forces into state institutions. The deal recognized the principle of a unified Syrian state while leaving questions about decentralization, military command and local administration unresolved.

Implementation stalled. The transitional government and the SDF accused one another of obstruction, and sporadic clashes occurred. The autonomous administration resisted parts of the new government’s structure, arguing that it did not represent Syria’s diversity. The delay reflected deep disagreements over whether SDF units would remain as organized formations or be absorbed individually into the Syrian army.

In January 2026, the transitional government launched an offensive against the SDF in northeastern Syria. On 18 January, the parties announced a 14-point ceasefire and integration agreement under United States sponsorship. The deal transferred Raqqa and Deir ez-Zor to government control, including oil fields, border crossings and facilities holding Islamic State prisoners. It provided for most SDF members to be reorganized into three brigades within a Syrian army division.

The agreement also addressed the status of Kobani and the withdrawal of non-Syrian fighters. Implementation proceeded over several months through military, security and administrative arrangements. On 20 August 2026, Abdi said integration of the SDF’s military, security and administrative institutions into the Syrian state had been completed and that foreign fighters had withdrawn.

On 25 August 2026, Abdi declared the SDF dissolved and fully integrated into the Syrian Army. The organization’s formal end closed a decade-long period in which it served as the main United States partner against the Islamic State. The transition transferred command and territory to Damascus, but practical integration and protection of local autonomy remained ongoing questions.

Assessment

The SDF was a multi-ethnic force that became central to the defeat of the Islamic State in Syria. Its alliance brought together Kurdish units, Arab groups and minority formations, supported by United States-led coalition air power. It also administered a large region and guarded detention facilities containing former Islamic State members.

The force faced tensions with Turkey, Damascus and local communities. Its governance model expanded women’s participation and local councils but restricted political opposition and was accused of human rights violations. The SDF’s relationship with the United States was militarily effective but politically limited.

The 2026 integration agreement and dissolution transformed the SDF from an autonomous armed alliance into part of Syria’s national security structure. Whether that transition protects communities and prevents renewed conflict will depend on the new government’s conduct, the treatment of former SDF members and the guarantees provided to northeastern Syria.