Analyst: U.S. Lost Chance to Stop Missile Tests

As the United States formulates its response to North Korea's missile tests, Robert Siegel talks with Ashton Carter, Professor of Science and International Affairs at Harvard University and co-director of the Harvard Stanford Preventive Defense Project.

Carter served as assistant secretary of defense for International Security policy during the Clinton administration and recently co-wrote an op-ed arguing that the United States should preempt a strike.