The SDF: America's Kurdish Alliance and Its Uncertain Future

The SDF was formally announced on October 11, 2015, combining the YPG/YPJ with Arab, Assyrian Christian, Turkmen, and other ethnic factions under US Special Operations Forces advisory presence. The US had been supporting YPG operations against ISIS since the Kobane siege (2014-2015), when Kurdish forces, with US airpower, halted ISIS's advance on the city in a 134-day battle that killed over 1,000 ISIS fighters. The SDF campaign against Raqqa — ISIS's declared capital — began in November 2016 (Operation Wrath of Euphrates) and ended with the city's liberation on October 17, 2017. The battle cost the SDF over 700 fighters and left Raqqa largely destroyed. The SDF-Women's Protection Units (YPJ) played a frontline combat role throughout, following the feminist military doctrine of Abdullah Öcalan (jailed PKK founder) — a globally noted phenomenon in which female fighters deliberately confronted ISIS's theological objection to being killed by women.