He sat with his back to the camera, a black scarf over his head hiding his identity. In a 47-minute televised interview with Al-Jazeera recorded in “liberated territory” in northern Syria, the leader of the Nusra Front, al-Qaida’s branch in Syria, said his group has no plans to attack the West. Its focus is toppling President Bashar al-Assad’s regime.

The choreographed media campaign by the Nusra Front and its leader, who goes by the nom de guerre Abu Muhammed al-Golani, capped the group’s rise as one the most powerful of Syria’s rebel factions. Nusra fighters played a key role in a string of victories in Idlib in northern Syria over the last two months, leading an effective rebel alliance known as the Jaish al-Fatah coalition, made up of six other Syrian Islamist groups. ...