Former US arms negotiator and Potomac Institute for Policy Studies Senior Fellow Amb. David Smith is closely following the Obama administration's evolving nuclear weapons policy. On April 8, President Obama and Russian President Dmitri Medvedev met in Prague to sign a new nuclear-arms reduction pact.  But many questions remain about the future of nonproliferation efforts. Amb. Smith offered comments to correspondent Sally Kidd of Hearst Television; click here to watch the Hearst stations' story in full.