Daniel Yergin, author and economic historian, discusses his book, "Shattered Peace: The Origins of the Cold War and the National Security State." He explains the key players in the Cold War and his thoughts on the Yalta and Riga Axioms. Yergin also explores the end of World War II and other events that led to the tensions between US and the Soviet Union.

Daniel Ellsberg, political activist and former military analyst, discuses his release of the Pentagon Papers and his thoughts on how the Vietnam War played out. He also discusses what he believes the next war could look like and how America, and the world, would be affected by nuclear war.