US military leaders have said the strength and sophistication of Islamic State militants pose a imminent threat to the United States.<br /><br />Their violent tactics including the beheading of American journalist James Foley have been met with horror. <br /><br />US officials are worried about the possibility that European and US nationals would return to their home countries after being radicalised fighting for IS in Iraq and Syria.<br /><br />“They’re beyond just a terrorist group, they marry ideology, a sophistication of strategic and tactical military prowess, they are tremendously well-funded, this is beyond anything that we’ve seen, so we must prepare for everything, and the only way you do that is you take a cold, steely hard look at it and get ready,” said Chuck Hagel, US Defence Secretary.<br /><br />Washington has not ruled out escalating cross-border military action in order to defeat IS, which has taken control of large swathes of Syria and Iraq this summer.
