John Kirby, the Retired Rear Admiral in the U.S. Navy, and Vali Nasr, the Professor of International Affairs at Johns Hopkins University, join Christiane Amanpour to discuss the attack on Saudi oil fields. Laurie Santos, the host of "The Happiness Lab" talks about her popular class at Yale University that teaches students how to be happy. Our Walter Isaacson talks to Documentary Filmmaker Ken Burns about his latest work, "Country Music."To learn more about how CNN protects listener privacy, visit cnn.com/privacyLearn more about your ad choices. Visit podcastchoices.com/adchoices