Self-Defense Forces is a multi-ethnic territorial defense militia and the only conscripted armed force in the Autonomous Administration of North and East Syria. As a self-defense force, manpower for the HXP is recruited locally.

The Manbij offensive, code-named Operation Martyr and Commander Faysal Abu Layla by the SDF, was a 2016 military offensive operation by the Syrian Democratic Forces (SDF) to capture the city of Manbij from the Islamic State of Iraq and the Levant (ISIL), and eventually, the ISIL-held areas through Al-Bab to Herbel, in the area referred to as the "Manbij Pocket" in the northern Aleppo Governorate. The main goal of the offensive was to cut off ISIL's last supply routes from Turkey, and to prevent ISIL fighters from escaping across the Syria-Turkey border. For the first five days of the offensive, the US-led coalition conducted over 55 airstrikes in support of the SDF. After capturing Manbij city on 12 August, the SDF announced that the offensive would continue until the whole countryside around Manbij was captured, though the offensive effectively ended shortly after the Turkish Armed Forces initiated Operation Euphrates Shield to prevent the SDF uniting the regions of Rojava.