Stanford University’s Siegfried Hecker, a prominent U.S. scientist who is believed to have been the last Westerner to visit North Korea’s Yongbyon nuclear complex, said North Korea would need to carry out at least one more nuclear test in order to develop a nuclear missile.
[thumb]http://www.reuters.com/article/2013/04/18/us-korea-north-hecker-idUSBRE93H0QK20130418[/thumb]