Key powers involved in Syria’s civil war have criticised the US for helping an allied Kurdish-led militia set up a 30,000-strong “border security force”. Turkey’s president vowed to “suffocate” efforts to train the Syrian Democratic Forces (SDF) and create what he called a “terror army”. Turkey considers Kurdish fighters, prominent in the SDF, to be terrorists.
Syria’s government decried the “blatant assault” on its sovereignty, and Russia warned it could lead to partition. With US help, the SDF has captured tens of thousands of square kilometres of territory from Islamic State (IS) militants.
In October, the alliance took full control of the northern city of Raqqa, the de facto capital of the “caliphate” declared by the jihadist group in 2014. Since then, SDF fighters have been advancing southwards along the eastern side of the Euphrates river valley, clearing the last remaining militants from the desert area.