The man, named as Colonel Scherbakov, worked for Russia's SVR foreign intelligence service, a successor agency to the KGB, where he oversaw a top- secret programme to dispatch long-term sleeper agents or "illegals" to the United States. Russian intelligence sources told the Kommersant newspaper that he was the traitor who had given the FBI the names of the ten sleeper agents who made up the ring, including glamorous spy Anna Chapman. In at least one case, he is even said to have taken part in an interrogation. In an echo of the Cold War, a Kremlin source was quoted as...