The three most prominent murders that are commonly blamed on Putin in the West are those of politician Boris Nemtsov in 2015, journalist Anna Politkovskaya in 2006, and former intelligence officer Alexander Litvinenko also in 2006. An official inquiry in Britain concluded it was likely that Putin was behind the assassination of Litvinenko, who was poisoned with the radioactive substance polonium-210. That's the closest anyone has come to pinning a murder on Putin. The KGB — the organization that taught Putin most of what he knows about the world — has a long tradition of assassinating "traitors," primarily defectors. In his memoir, Oleg Kalugin, a former KGB general, recalled an episode from his work in the U.S. under journalistic cover in the 1960s. His boss, the New York station chief, told him he'd propose to Moscow that Kalugin shoot Yury Nosenko, a high-level defector to the U.S.: