Twenty-one months into Syria’s uprising-turned-insurgency against President Bashar Assad, the influence of Islamist groups has grown, none more so than the most extreme of the lot: Jabhat al-Nusra. The group, which boasts about 7,000 fighters, has declared a global jihad and is the only battalion recognised by al-Qaeda. According to America, it is an offshoot of the terrorist group‘s Iraqi branch.