Significance: The SDF accounted for 25% of all fighting recorded against the Islamic State in Syria in November, and captured an estimated 1700 km2 from the Islamic State in Hasaka province, according to the latest IHS Conflict Monitor data.

Implications:
A continued successful SDF advance through the Khabur River Valley would probably shift the balance of power in Deir al-Zour province against the Islamic State, encouraging local tribes, such as the Shu’aytat, to rise up against them.

Outlook: Expelling the Islamic State from the Khabur River Valley and Deir al-Zour would effectively split the ‘Caliphate’, disrupting the movement of fighters and supplies between Syria and Iraq, and weakening their ability to defend Raqqa and Mosul.

The Syrian Democratic Forces announced their formation on 11 October 2015 in Hasaka, and by late November accounted for 25% of all fighting recorded against the Islamic State in Syria. The group has an approximate strength of 4,000 fighters. By 23 November, the group had captured an estimated 1700 km2 from the Islamic State in Hasaka province, equating to 2% of the Islamic State’s territory in Iraq and Syria. This included the town of al-Hawl, and the former Syrian Army 121 Regiment Artillery Base, which were both used as staging points for Islamic State attacks into Kurdish territory. Although the SDF presents itself as a unified national force, it consists primarily of Kurdish PYD fighters, with smaller contingents of Sunni Arab tribesmen, and some Assyrian, Turkmen and Armenian fighters. There does not appear to be a strong central leadership, and the composition of its forces probably fluctuates, depending on where the SDF are fighting.