Islamic State have released a new decapitation video, threatening America for the second time and urging the Kurds to break from their alliance with the West against the caliphate. The chilling video shows footage of 15 Kurdish soldiers all dressed in orange boilers suits . It then cuts to one of the prisoners kneeling before three masked jihadists (right), who warn America to cease its support of the Kurdish people. They warn they will continue beheading more of the prisoners if America and the Iraqi Kurdistan continue to work together, before unsheathing a knife and killing the kneeling prisoner. The terrifying execution comes just hours after 300 captured Syrian soldiers were executed in the desert