Hundreds of Britons, including the man who killed James Foley, are fighting for ISIS

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Marco Werman: On that video showing James Foley's beheading, the masked militant standing next to Foley is heard speaking with a British accent. I asked Usama Hasan in London if he was surprised to hear that. Hasan is senior researcher at the Quilliam Foundation, which researches Islamic Extremism in Britain. Usama Hasan: I was shocked by the accent being totally British but not particularly surprised, I have to say. The warning signs have been there for the last year or so. We had the murder of a British soldier on the streets of London in May, last year. A beheading there also, with two young British men arguing about Western foreign policy and expressing anti-Western sentiments. Then over the last year, we've seen hundreds of British young men and even women go to Syria and Iraq and join ISIS. On social media, they've shared pictures of severed heads, they've expressed their delight and rejoice at the murder and execution of their enemies, including decapitation and beheadings. They've expressed the desire to slaughter all non-Muslims and Shia Muslims, other Muslims they don't agree with. So unfortunately, this particular video, it is a shock but not a total surprise. It seems to be a young British man who's delivering the message firstly and then decapitating poor James Foley. Werman: You say the accent is totally British. It sounded a little muffled to me. Has it been verified that this man who executed Mr. Foley is in fact British or from the UK? Hasan: It's not completely confirmed of course because we don't know the identity of this man but everyone that I've spoken to here in Britain agree it's a British accent. We obviously know the local dialect and accents very well and I don't know anybody in Britain who doubts that it's a British man. Werman: There's news last week from Scotland Yard that about 500 Britons are among the thousands of Westerners who have joined the fight in Iraq and Syria. Why is there so much radical activity coming from the UK? Hasan: The radical activity in the UK is due to a number of reasons. Most importantly, I would say, is the fact that Britain has been home to many leading radicals from the world of political Islam. Since the 1970's, the UK amongst Europe had a very kind of generous asylum policy and gave refuge to many people who were radical Islamists but who were persecuted by oppressive dictatorships in the Muslim majority world. I myself, as a young man, at the age of 19 went to Afghanistan to fight against the Communist forces allied to the Soviets. There's been an unbroken line, in fact, from the jihads of the 90's in Afghanistan and Bosnia, Kashmir and Chechnya, through to the post-9/11 phase and now what we're seeing in Somalia and most recently Syria and Iraq in terms of jihadist fighters, so there's a long history here. Werman: You're talking several chapters of a history and today I guess we're talking about the second generation of those people who moved to the UK in the 70's. What prompted you to join in that jihad in Afghanistan? Hasan: The fact that drove me to join that were very similar to the ones actually inspiring these young men. It was a sense of disillusionment from Britain. It was a feeling that we weren't accepted and welcome in the society. Britain was a lot more racist in the 70's and 80's, for example. That has changed in Britain but this current generation grew up in the post-9/11 phase, with the war on terror often being misunderstood or used to justify suspicion against Muslim communities in Britain and in Europe. Werman: What made you stop, though? Hasan: What made me stop was the opposite of that process, which was becoming more and more integrated. I spent 20 years as a committed Islamist but it was a gradual journey out and unfortunately time is required often to bring people away from these kinds of extremist mindsets, which we don't have at the moment. But what we can hope for is there are many other people like me who have been through similar journeys, who can collectively impart, who hope, some of that experience. Werman: Usama Hasan with the Quilliam Foundation in London. Thank you very much for speaking with us today. Hasan: Thank you.