The Syrian Democratic Forces (Kurdish name: Hêzên Sûriya Demokratîk, arabic name: قوات سوريا الديمقراطية), usually shortened as SDF or QSD, are an alliance of Kurdish, Arab, Turkmen, Assyrian and Armenian militias mainly fighting against ISIS, Al-Nusra Front and other Jihadist groups in the Syrian Civil War.The goal of the group is to establish and protect the federal region “Rojava – Northern Syria”.
YPG / People’s Protection Units
The YPG is the military wing of the kurdish political party PYD. The group has approximately 50000 fighters and many foreign volunteers.
The YPG appeared as a force in the syrian civil war in 2012 after the Syrian Arab Army withdrew from Kurdish cities.
The YPG didn’t take an offensive posture in the Syrian war at first. Aiming generally to defend Kurdish-majority areas, it avoided fighting other forces within the areas around them. The YPG changed this policy when Ras al-Ayn was captured by the al-Qaeda affiliate Jabhat Al-Nusra. The People’s Protection Units started attacking surrounding areas under government control to stop the FSA from gaining more power in the region. But the YPG mostly fought against jihadist groups. The battle of Ras al-Ayn ended in July 2013 with a YPG victory.
The inter-rebel conflict throughout the Syrian civil war led to open war between the FSA and ISIS in January 2014. The YPG worked together with the FSA to fight ISIS in Ar-Raqqah province. However, the general outcome of this fight were immense advances by ISIS that separated the eastern part of Rojava from the remaining parts. ISIS continued its success by attacking the YPG in Kobanî canton in March 2014 and fighting its way to the outskirts of Kobanî in September 2014.
With the world fearing a massacre during the siege of Kobanî, the US-led coalition began close air support to the YPG. Whereas most analysts expected ISIS to quickly crush the Kurds in Kobanî, the YPG placed up a stunning and determined resistance, which ultimately led to the victory of YPG forces.
With american air support, YPG forces started offensives near Hasakah and to the west of Hasakah which culminated in the conquest of border city Tell Abyad, linking up Kobanî with Hasakah in July 2015. After this offensives, kurdish forces had begun to make advances into areas that didn’t have a kurdish majority.
YPJ / Women’s Protection Units
The Women’s Protection Units (YPJ) is a kurdish military group that was established in 2012 as the female brigade of the YPG militia. The YPG and YPJ are the armed wing of the kurdish PYD that has taken the control over large areas in Syria’s north known as Rojava.
The organization grew out of the kurdish resistance movement and by now has 10,000 volunteer female fighters between the ages of 18 and 40.
The YPJ joined its brother organization YPG in the fight against jihadist militias in the Syrian civil war. The Women’s Protection Units play a big role in the general fight against ISIS and in the battle of Kobanî.
Jaysh al-Thuwar / Army of Revolutionaries
Jaysh al-Thuwar is an armed rebel group, participating in the Syrian Civil War. They consider themselves as a militia uniting Arabs, Turkmens and Kurds. The group has roughly 3000 fighters.
Although the Army of Revolutionaries consistently emphasized that they are part of the FSA, the group still got in an open conflict with jihadist and rebel militias. The reason of hostility was the alliance between Jaysh al-Thuwar and the kurdish YPG. Subsequently the Army of Revolutionaries further deepened its bonds with the YPG and joined the SDF.
Jaysh al-Sanadid is a militia formed by the Arab Shammar tribe to fight against the ISIS and other jihadist groups. The Shammar tribe is based in Jazaa and Til Koçer regions of the Cizîr Canton of Rojava and also in Iraq. The Al-Sanadid Forces are associated with tribal leader and governor of Jazirah district Hamidi Daham al-Hadi.
The militia has around 9000 fighters and joined the Syrian Democratic Forces in late 2015.