The Road to ar-Raqqah: Background on the Syrian Democratic Forces

"The U.S. built the SDF in late 2015 by recruiting a “Syrian Arab Coalition” to fight alongside the YPG and other local militias. The SDF continued to attract Arab fighters in the lead up to operations against ISIS in ar-Raqqah, including the recent inclusion of members of the Free Officer’s Union, a group of several high-ranking Syrian Arab Army defectors, in October 2016. "