All nuclear explosions create EMP [ElectroMagnetic Pulse], although the pulse dissipates rapidly in explosions close to the earth’s surface. But if a nuclear device were detonated above the earth’s atmosphere, there would be no blast, shock, heat or roar—only an invisible, speeding electromagnetic pulse. At this high altitude, gamma rays and X-rays produced by the blast shoot through space and spread out over an extraordinarily wide area. Scientists estimate that one 10-megaton burst 300 miles above the center of the United States would create an intense burst of EMP capable of blanketing the entire country with a pulse that would put 50,000 volts into every meter of antenna. Metal objects such as power and telephone lines would pick up the jolt of electricity and deliver it to computers and communication centers, where delicate silicon chips would be knocked out of action.…

…EMP has become a growing concern in the last few years because the rapid computerization of almost every aspect of military and civilian life in this country has left the nation extraordinarily vulnerable to its power.