The war in Syria for the past four years seemed to be effectively over.
President Bashar al-Assad’s rule remains largely unchallenged in the country’s major cities, while some other parts of Syria remain outside his direct control.
This includes Kurdish-majority areas in the east that have been more or less separated from Syrian government control since the early years of the conflict.
In the south, where a revolution against Assad’s rule began in 2011, unrest continues, albeit relatively subdued.
In Syria’s vast desert, militants from the so-called Islamic State group continue to pose a security threat, especially during truffle hunting season, when people head to the area in search of the highly lucrative delicacy.
And in the northwest, the province of Idlib was held by groups of jihadists and rebels who were driven there during the height of the war.
The dominant force in Idlib is the one that launched the surprise attack on Aleppo, HTS.