According to Benotman, the ultimate aim of al-Nusra is the creation of an Islamic State in Syria and the Levant. To begin with, it set about recruiting fighters and training them, collecting weapons and creating safe havens…

Last week al-Nusra demonstrated the lethality of a new tactic – driverless car bombs operated by remote control, Benotman told CNN. He says the technology was used to destroy a gate at an airbase in Idlib and will raise fears that it could one day be used in an attack in the West.

If al-Nusra’s fighting strength is some 5,000 members, as the Quilliam report estimates, that would be comparable to U.S. government estimates of AQI at the peak of the Iraq insurgency. But rebel commanders say that the group makes up less than 10% of the brigades fighting the regime.

While al-Nusra is mainly made up of Syrians, it includes a significant number of fighters from other Arab countries. In recent months a growing number have arrived from Saudi Arabia and the Gulf, but Iraqis and Jordanians constitute the majority of foreign fighters…

According to the Quilliam study, “the designation (by the U.S.) of al-Nusra as a terrorist organization has only served to reinforce jihadist support for the group.