In the pre-9/11 past, threats to international security could usually be attributed to this or that "dangerous" or "unstable" nation-state. Today, however, such threats are quite often attributed not to nation-states, but to "non-state actors" like Boko Haram, Al-Qaeda, or the Islamic State (IS). We're speaking about this dramatic shift in thinking -- and in action, and in policy -- with Dr. Dan Caldwell, a professor of political science at Pepperdine University’s Seaver College. Dr. Caldwell recently gave an address to the Tulsa Committee on Foreign Relations entitled "Seeking Security in an Insecure World," and we interviewed him while he was in town. He's the author or co-author of several books, including "Vortex of Conflict: U.S. Policy Toward Afghanistan, Pakistan, and Iraq" and "Seeking Security in an Insecure World," which is now in its 3rd Edition. Over the years, Dr. Caldwell has received the Professor of the Year Award at Pepperdine University, the Charles and Harriet Luckman Teaching Award, the Pew Faculty Fellowship in International Affairs at Harvard University, and a United States Institute of Peace Fellowship.