joining us now is richard barrett. he used to run britain's anti-terror operations for the last ten years. richard barrett, thanks very much for joining us. the prime minister's measures would require all airlines to comply with a government so-called no-fly list or be banned from landing in britain. the uk also raised its terror threat level to severe, which means a terror attack is, quote, highly likely. a lot of terror action going on right now, anti-terror action, i should say. someone who used to run britain's anti-terror operations, does this response right now surprise you? >> well, clearly there's a lot of anxiety in the united kingdom just as there is everywhere else in the world where -- from where foreign fighters have gone to fight in syria and iraq. and it makes every sense, of course, to introduce measures that make it harder for people to go and harder for people to come back. but, of course, that doesn't necessarily stop them all from going, nor indeed stop them all from coming back. and i think what i'