In addition to targeting the Islamic State, the United States has launched attacks on the al-Qaeda-linked Khorasan group in Syria, saying it was “nearing the execution phase” of an attack on the United States or Europe, most likely an attempt to blow up a commercial plane in flight. Meanwhile, the Syrian al-Qaeda affiliate, the al-Nusra Front, says its leader, Abu Yousef al-Turki, has been killed in the strikes.