Syria holds strategic importance for Moscow and Tehran, which have both bolstered Syrian President Bashar Assad's regime at critical moments.

Last week, apparently catching the world by surprise, Hayat Tahrir al-Sham (HTS) rebels launched a surprise offensive against government-controlled positions in northwestern Syria. Within 72 hours, incredibly,

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.