President Obama's nuclear security summit, held in Washington, D.C. and hosting 46 world leaders, wrapped up last night with a request from the president. He called on all the nations present to cooperate in keeping nuclear material out of the hands of terrorists.
Obama said, "Every nuclear power, every country that has a civilian nuclear energy program, has to take better steps to secure these materials.”
We talk with David Sanger, Chief Washington correspondent for The New York Times, and the author of "The Inheritance: The World Obama Confronts and the Challenges to American Power," who has the latest of what came out of the summit. Also, Sharon Squassoni, who directs the Proliferation Prevention Program at the Center for Strategic and International Studies, talks about who is buying and selling nuclear material on the black market.