Bill Gates and Steve Jobs could probably tell you terrific stories about where they were and what they were doing when they realized the true implications of the electronic age. But you'd get a somewhat more interesting account from any aging electrician in Hawaii: That's because one evening there in July 1962, 100 burglar alarms suddenly sounded and 300 street lights suddenly blinked out for no apparent reason. All over the region, phones, radios, and televisions went dead without warning.
The cause, it turned out, was 800 miles due west and 250 miles up in the air: A 1.4 megaton nuclear weapon had been detonated some 1.32 million feet above tiny Johnston Island in the Pacific. It was a planned test, but what the U.S. military hadn't anticipated was high-energy electrons subsequently bombarding a large swath of the Earth's surface, crippling thousands of electrical circuits. Oops. (The same electrons also knocked out one-third of the satellites in low Earth orbit at the time, including Telstar, the very first operational communications satellite.) That test is when weapons engineers first realized that nukes were not just good for blowing up and melting stuff. They could also knock out electronics far in the distance.
Fast-forward three decades into an industrialized world that is almost entirely electronic and interconnected. We are so dependent on electrical circuits and computer switches that the Pentagon has come to fear a nuke's "electro-magnetic pulse" almost as much as its big boom. The nightmare scenario is this: A rogue nation like North Korea or a stateless terrorist like Bin Laden gets hold of a nuclear weapon and decides not to drive it into a large city but rather to launch it on a Scud-type missile straight into the atmosphere from a barge off the East Coast. With sufficient megatonnage and sufficient altitude, this single EMP attack could debilitate electrical and computer systems over half the United States, including the entire Eastern Seaboard. No one would be killed by the explosion itself, but tens of thousands could die quickly from electrical malfunctions in hospitals and elsewhere. And while no one can say for sure in advance, many think that the electrical grid could be disabled for months or even years. In an instant, the world's superpower could become a candle-powered 19th-century museum.
Don't try to compare this to an ordinary blackout, when an end is always in sight. You have to imagine a s t r e t c h b l a c k o u t—months or years. ATMs, computers, and cars would be parked indefinitely. Cash, bicycles, and bottled water would become the currency of the day. Bloggers would switch to pens and poster board. Families with emergency reserves of cash, food, water, medicine, etc. would be breathing a lot easier than the rest of us. Even when electricity returned, most hard drives would not:Only nonmagnetic backups (paper, CD-R, microfiche, etc.) and specially shielded hard drives would be sure to survive a massive EMP attack.
The worse news is that EMP weapons don't require a nuclear detonation—there are other ways to achieve the same effect. I must also note that EMP may not be all that dastardly: There is significant debate among technical experts as to what the collective damage would look like—after all, Hollywood has made EMPs look either fun and sexy ( Ocean's 11) or dangerous and sexy ( Dark Angel). Still, plenty of officials are terrified by the prospect.
They are also troubled by the better-known possibility of a massive cyberattack—a "superworm," launched from a lone computer in Karachi or Bethesda, quickly infiltrating tens of thousands of unsuspecting PCs and turning them into unwitting attack drones. "It's not very difficult technically to command all those zombie computers to do something simultaneously," Harvey Mudd College computer scientist Geoff Kuenning told me. A truly devastating attack would cost millions of dollars, take serious planning, and be highly labor-intensive—no world-class superworm is going to arise from a high-school prank. But the consensus seems to be that the destructive payoff could be fairly high.
This is the unavoidable reality of our global electronic village: Our connectivity is also our vulnerability. A highly sophisticated cyberattack could go after telecommunications, aviation, the financial industry, the electrical power grid, the water supply, or the Internet itself. Any system that relies in part on computers is theoretically vulnerable, and the only firewall guaranteed to be immune from attack is complete disconnection from the Internet and from other connected computers. A recent congressional report cites the warning of University of Pittsburgh terror expert Phil Williams: a crippling attack on the federal-funds transfer system, which facilitates financial transactions across the country. "You can find out on the Internet where the backups are," Williams pointed out. "If those could be taken out by a mix of cyber and physical activities, the U.S. economy would basically come to a halt. If the takedown were to include the international funds transfer networks CHIPS and SWIFT then the entire global economy could be thrown into chaos." This may not sound terribly likely, but consider that the Internet itself would have seemed a pretty bizarre notion as recently as 1990.
Short of installing your own ethanol generator and shielding your entire house in lead, what can an individual do to prepare for an EMP or cyberattack? Less than you think. This is a case where we have to rely on the professional paranoids—the software wizards in anonymous Virginia and California office buildings who are devising defenses against all the clever electronic assaults they can imagine. Still, you can take a few precautions. Start with the same disaster kit you should already have handy for other emergencies: nonperishable food, water, flashlight, radio, batteries, medicine, cash (small bills), and so on. Now throw in a regular computer backup—ideally onto a nonmagnetic medium such as CD-R. (If the computing industry decides to care about this issue, they could shield future personal computers from EMP attacks for a marginal cost, but to individually retrofit your current PC is prohibitive.) Print out some of the really important stuff and file it away, old-fashioned style. In a post-EMP world, your filing cabinet might well be the smartest tool around.