The prisoner swap taking place Thursday to free Evan Gershkovich, Paul Whelan and others is a complex one that involves multiple countries. CBS News intelligence and national security reporter Olivia Gazis has more on the details of the exchange. Following Gazis’ reporting, William E. Pomeranz, senior fellow and former director of the Wilson Center’s Kennan Institute, and former U.S. ambassador to Russia John Sullivan joined CBS News to discuss how an exchange like this works. Source