It's possible: Imagine no phone, no food, no fuel

'As a scientist and engineer now serving my 17th year on the House Armed Services Committee, I have studied the threat of EMP with the world's experts,' said U.S. Rep. Roscoe Bartlett. 'It is real.'"

"A high-altitude EMP results from the detonation of a nuclear warhead at altitudes above 25 miles over the Earth's surface, and covers the area within line-of-sight from the bomb. The immediate effects of EMP are disruption of, and damage to, electronic systems that are indispensable to the operation of critical national infrastructures – the electric power grid, wired and cell telephone systems, fuel handling, land and air transportation, government operations, banking and finance, food storage and distribution, and water treatment and supply – that sustain our economy, military power and civilian population."