Col. Wilkerson on 9/11, the Iraq war and Crimea

In tonight's “Conversations with Great Minds" Thom talks US military and foreign policy with Colonel Lawrence B. Wilkerson, the former Chief of Staff to former Secretary of State Colin Powell. And Thom talks with Ploughshares Fund President, Joe Cirincione, author of the new book “Nuclear Nightmares: Securing the World Before It Is Too Late” in a special re-air of last weeks “Conversations with Great Minds.”