Pentagon Papers whistleblower sounds alarm over nuclear arms race
Vladimir Putin stunned the world this week by announcing an array of new nuclear weapons including a cruise missile with unlimited range and a nuclear-tipped underwater drone. Daniel Ellsberg, the whistle-blower who released the Pentagon Papers in 1971, has studied the dangers of nuclear conflict for decades. Alex Wagner sits down with him to discuss his new book, "The Doomsday Machine: Confessions of a Nuclear War Planner."