Fred Burton, former deputy chief of counterterrorism at the Diplomatic Security Service and the author of GHOST: Confessions of a Counterterrorism Agent, Chasing Shadows: A Special Agent's Lifelong Hunt to Bring a Cold War Assassin to Justice, and Under Fire: The Untold Story of the Attack in Benghazi joined me shortly after the attack on Sergei Skripal. Skripal. a former Russian double agent now living in the UK, was poisoned with a Russian novichok nerve agent developed during the Soviet era. We look at the many implications of this brazen attack, security issues surrounding it, and the need for a serious response.