North Korea’s last round of tests, conducted in May 2009, appear to have included a “super-EMP” weapon, capable of emitting enough gamma rays to disable the electric power grid across most of the lower 48 states, says Dr. Peter Vincent Pry, a former CIA nuclear weapons analyst and president of EMPact America, a citizens lobbying group. Samore, who handles arms control and non-proliferation issues, warned that “additional strong sanctions will be imposed on the North with the support of Russia and China." North Korea’s nuclear tests have been dismissed as failures by some analysts because of their low explosive yield....