Witnesses testified on U.S. policy toward North Korea. Earlier in the day, North Korea threatened a pre-emptive nuclear attack on the United States in retaliation for new United Nations sanctions. 
WITNESSES:
Panel One:
Glyn T. Davies, special representative for North Korea policy, Department of State
Panel Two:
Stephen W. Bosworth, dean, The Fletcher School of Law and Diplomacy, Tufts University, Medford, Mass.
Robert G. Joseph, senior scholar, National Institute for Public Policy
Joseph DeTrani, president, Intelligence and National Security Alliance