Islamic State (IS) released a video on Sunday that appeared to show the beheadings of 21 Egyptian Christians in Libya. The footage showing the deaths of the Egyptian martyrs appeared on the Twitter feed of a website that supports IS. A caption on the five-minute video read: “The people of the cross, followers of the hostile Egyptian church.” Before the killings, one of the militants stood with a knife in his hand and said: “Safety for you crusaders is something you can only wish for. . ." What does it all mean?