ISIS poses a “greater and deeper threat to our security than we’ve seen before” said Prime Minister David Cameron. His statement follows a decision to raise the UK's terror threat level from "substantial" to "severe" over events in Iraq and Syria. READ MORE: http://on.rt.com/xsypeu<br /><br />RT LIVE http://rt.com/on-air<br /><br />Subscribe to RT! http://www.youtube.com/subscription_center?add_user=RussiaToday<br /><br />Like us on Facebook http://www.facebook.com/RTnews<br />Follow us on Twitter http://twitter.com/RT_com<br />Follow us on Instagram http://instagram.com/rt<br />Follow us on Google+ http://plus.google.com/+RT<br /><br />RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.