Russia has been bombing Islamic State targets in Syria since the militant group claimed responsibility for the downing of a Russian airliner over Egypt on October 31. The beheading comes as United States led coalition forces continue to face major challenges trying to defeat the militant group. ___________________________________从10月31日,军队宣称要为俄罗斯开往埃及的客机坠落事件负责之后,俄罗斯已经在叙利亚共和国向伊斯兰国投了炸弹. 被砍头的间谍事件,使得美国带领联合军队继续面临挑战,试图打败军队组织.______________________________