Daniel Ellsberg was best known for leaking the Pentagon Papers, but he was also a lifelong anti-nuclear activist, stemming from his time working as a nuclear planner for the U.S. government. In December 2017, he joined us to discuss his memoir, The Doomsday Machine: Confessions of a Nuclear War Planner. “This was an actual war plan for how we would use the existing weapons,” he noted, “many of which I had seen already that time.”