From 1941 to 1945, Joseph Stalin exchanged more than six hundred messages with Allied leaders Churchill and Roosevelt. The correspondence ranged from intimate personal greetings to weighty salvos about diplomacy and strategy, and they reveal political machinations and human stories behind the Allied triumvirate.

Today's guest is David Reynolds, author of a new book about the correspondence between the three. He helped edit a volume based on the correspondence among the Allied triumvirate, which illuminated an alliance that really worked while exposing its fractious limits and the issues and egos that set the stage for the Cold War.