World leaders at the Nuclear Security Summit this week hope to make progress toward preventing nuclear terrorism. But how do the myriad parts that go into making a nuclear weapon get into the hands of terrorists and rogue governments in the first place? Host Linda Wertheimer talks to Mark Hibbs, a senior associate at the Carnegie Endowment for International Peace, who has actually searched out nuclear traffickers and asked just that.

http://www.npr.org/templates/story/story.php?storyId=125837359