After 13 years of war that began with street protests during the heady days of the Arab Spring and morphed into one of the bloodiest civil conflicts in the Middle East’s recent history, the regime of Bashar al-Assad, the Syrian strongman, collapsed in just over a week.

Sunni rebels – some of them former jihadists – who had broken out of the north-west province of Idlib swept into the capital Damascus after overrunning the major cities of Aleppo, Homs and Hama on their way south.