For the last eight years in Syria, a civil war, borne out of the Arab Spring protests, had come to something of a standstill.

The frontlines were largely frozen, with Syrian president Bashar al-Assad having control of the major cities, while militant groups wrestled for primacy in the regions.

That is, until the attack on the weekend, from a rebel force with origins in Al Qaeda.

So what happens now?

The last time Assad had his territory and military rule threatened in such a fulsome way, Russia came to his rescue, in a brutal campaign that involved the use of chemical weapons on Syrians.

Today, digital foreign editor Chris Zappone on the story behind the rebel group that took the city, why they want to topple Assad, and what role his allies might play again.

Audio credit:

• What happened after the Arab Spring?, Al Jazeera.