Two rebel groups are leading the push. One is Hayat Tahrir al-Sham ( HTS ), which emerged from al-Qaeda’s Syrian affiliate. It cut ties with the jihadist group in 2017 and has since set up a provisional government in rebel-held Idlib province in north-west Syria. The other faction, the Syrian National Army ( SNA ), is a Turkish proxy.

In just a few days, a patchwork of rebel forces has seized control of a broad stretch of land in the west and northwest of Syria. But it’s unclear just how much support Syria’s weakened allies can provide.