The Syrian Democratic Forces (SDF)[g] is a Kurdish-led[14][106][107] coalition of U.S.-backed left-wing[108][109] ethnic militias and rebel groups, and serves as the official military wing of the Autonomous Administration of North and East Syria (AANES; also unofficially known as Rojava).

[113][114] Formed as a rebel alliance in the Syrian civil war,[115][116] the SDF is composed primarily of Kurdish, Arab, and Assyrian/Syriac, as well as some smaller Armenian, Turkmen and Chechen forces.

[117][12] It is militarily led by the People's Protection Units (YPG), a Kurdish militia which is designated as a terrorist group by both Turkey and Qatar.

Major enemies include al-Qaeda affiliates, the Islamic State of Iraq and the Levant (ISIL), the Syrian National Army (TFSA), the Turkish Armed Forces, and their allies.

Geographically focused on the Jazira Region in northeast Syria were the Assyrian Syriac Military Council (Mawtbo Fulhoyo Suryoyo, MFS) and the al-Sanadid Forces of the Arab Shammar tribe, both of whom had cooperated with the YPG in fighting ISIL since 2013.

[132] Geographically focused on the Manbij Region was the Army of Revolutionaries (Jaysh al-Thuwar, JAT), itself an alliance of several groups of diverse ethnic and political backgrounds, who had in common that they had been rejected by the mainstream Syrian opposition for their secular, anti-Islamist views and affiliations.

In 2017, then-Commander of U.S. Special Operations Command Raymond Thomas stated that they were aware of Turkey's concerns about the YPG's ties to the PKK since 2015.

[143] At the end of October, the al-Shaitat tribal militia, the Desert Hawks Brigade, joined the SDF to fight ISIL in the southern countryside of Hasakah Governorate.

[146] With continuous growth in particular due to Arab groups and volunteers joining, in March 2016 only an estimated 60% of the men and women in the SDF fighting force were ethnic Kurds.

[149] The next month in December 2016, Colonel John Dorrian, the Operation Inherent Resolve spokesman, stated that the SDF contained around 45,000 fighters, of which more than 13,000 were Arabs.

Colonel John Dorrian, 75 percent of the SDF forces fighting in Operation Wrath of Euphrates to isolate ISIL's de facto capital of Raqqa were Syrian Arabs, a reflection of the demographic composition of that area.

[191] On 15 March 2017, a video surfaced that showed members of the Northern Sun Battalion reportedly torturing an ISIL fighter, who had been captured while planting mines.

The Manbij Military Council condemned the act, and announced that the involved Northern Sun Battalion fighters would be held for trial for violating the Geneva Conventions.

[265] On 24 April 2024, Amnesty International reported that there is a large-scale human rights violation of more than 56,000 people including 30,000 children and 14,500 women held indefinitely in at least 27 detention facilities for those with "perceived IS affiliation".

Detainees are held in inhumane conditions and subjected to torture including severe beatings, stress positions, and electric shocks with thousands having been forcibly disappeared.

Women were also subjected to sexual and gender based violence by SDF security members as well as attacks by other prisoners for perceived "moral" infractions.

[267] The Turkish government claimed that the YPG was carrying out ethnic cleansing of non-Kurdish populations as part of a plan to join the Jazira and Euphrates regions into a single territory.

[281] On 29 June 2019, Abdi, as representative of the SDF, signed the action plan of the United Nations aiming to prevent the enlistment of child soldiers in the armed forces.

[283] On 2 April 2016, SDF members and local police fired at a protest march from Umm Hajira to al-Hawl, killing a 15-year-old and injuring over a dozen others.