As President Obama has said, the prospect of nuclear terrorism is “the single biggest threat to U.S. security, both short-term, medium-term and long-term.” How great is the threat of nuclear weapons’ falling into terrorists’ hands and what more can be done to prevent it?

On July 29, Joe participated in the Nuclear Security Panel with MacArthur Foundation President Bob Gallucci, the Hewlett Foundation's Megan Garcia, and others, as part of the 2011 Aspen Security Forum. This panel was moderated by Susan Glasser of Foreign Policy. A clip of the panel is below.