On April 30, South Korean officials told The Korea Times and YTN TV that North Korea’s test of a medium-range missile on April 29 was not a failure, as widely reported in the world press, because it was deliberately detonated at 72 kilometers altitude. 72 kilometers is the optimum burst height for a 10-Kt warhead making an EMP attack. … According to South Korean officials, “It’s believed the explosion was a test to develop a nuclear weapon different from existing ones.” Japan’s Tetsuro Kosaka writes in Nikkei, “Pyongyang could be saying, ‘We could launch an electromagnetic pulse (EMP) attack if...