海角大神

It is an unsettling doomsday scenario: A ballistic missile is launched from a freighter near America鈥檚 shores, setting off a nuclear explosion in the atmosphere. The blast generates electromagnetic pulses (EMPs) that could take out the nation鈥檚 electrical grid and bring civilization as we know it 鈥渢o a cold, dark halt.鈥�

This warning comes from the former director of the CIA, James Woolsey, in little-noticed testimony recently before the House Armed Services Committee.

A nuclear weapon would be detonated in orbit 鈥渋n order to destroy much of the electric grid from above the US with a single explosion,鈥� he told lawmakers last week. 鈥淭wo thirds of the US population would likely perish from starvation, disease, and societal breakdown. Other experts estimate the likely loss to be closer to 90 percent.鈥澛�

This dire forecast included warning of an 鈥渋ncreasing likelihood that rogue nations such as North Korea (and before long, most likely, Iran) will soon match Russia and China in that they will have the primary ingredients for an EMP attack: simple ballistic missiles such as SCUDs that could be launched from a freighter near our shores.鈥�

Mr. Woolsey sprinkled in a bit of intelligence as well. 鈥淚n 2004,鈥� he noted to lawmakers, 鈥渢he Russians told us that their 鈥榖rain drain鈥� had been helping the North Koreans develop EMP weapons.鈥�

So, how plausible is this sort of scenario? A number of defense analysts take issue with the idea that an EMP attack on the US is imminent, or even particularly likely.聽They also suggested the outcome of the attack would not be so dire.

鈥淚 think the wild hysteria that鈥檚 greeted EMP attacks lately is wildly overstated,鈥� says James Lewis, director of the Strategic Technologies Program at the Center for Strategic and International Studies in Washington.

鈥淪o if you鈥檙e North Korea, and you鈥檝e got a nuclear weapon, and you detonate it over the United States, what鈥檚 going to happen next? The answer is hundreds of nukes will descend on you from the US,鈥� he says. 鈥淪o why would you waste the round? If they鈥檙e going to shoot a nuke at us, they鈥檙e not going to bother with this EMP stuff.鈥�

What鈥檚 more, although Woolsey told lawmakers that 鈥渕odern electronics are a million times more vulnerable to EMP than the electronics of the 1960s,鈥� Mr. Lewis argues that radiation hardening has been built into many modern electronics, through chips that have become more sophisticated. 鈥淏efore, there were vacuum tubes, and now you鈥檙e using a chip that can withstand a fair amount of radiation,鈥� Lewis says.

So what鈥檚 the bottom line? If a country or terrorist group 鈥渨ere crazy enough to shoot a nuclear weapon up over Washington, D.C. [to try to create an EMP], you might be able to fry 30 percent of the electronics in the city,鈥� Lewis says.

Solar flares can create EMPs as well, Woolsey noted, citing a 1989 solar-generated pulse that, he told lawmakers, 鈥渆ffectively destroyed Quebec鈥檚 electric grid.鈥� According to an article on a NASA website that looked back at the event 10 years later, the power was out in Quebec for 12 hours.

While an EMP attack may not be likely, the possibility raises some interesting strategic questions, says Paul Scharre, project director for the 20YY Warfare Initiative at the Center for a New American Security.聽

鈥淚f a nuclear-armed actor, instead of actually killing civilians with a nuclear weapon, lights it off at a high altitude,鈥� he asks. 鈥淒oes that cross the nuclear threshold? What鈥檚 the appropriate response? How would we respond? There鈥檚 not really a good answer for that.鈥� 聽