Imagine a coordinated attack by terrorists striking major electric power transmission lines and facilities in strategic places throughout the American Midwest and Northeast. They are able to knock out more than 250,000 megawatts of peak load electrical capacity and throw more than 50 million people into darkness over a 240,000-km area in the United States and Canada. Without electric power, a variety of other critical services also fail, including water supplies, hospital facilities, and major financial markets all over the globe. Ultimately, security systems are themselves disabled, leaving key infrastructures vulnerable to additional terrorist attacks.

Sound improbable? Many of these conditions actually occurred during the U.S. and Canada blackout of August 14, 2003, caused not by terrorists but by the failure of electric transmission systems themselves. While power was restored quickly in some areas, other portions of major metropolitan centers were without power for more than 24 hours, and some lost service for several days. A report issued in 2002 by a task force headed by former senators Gary Hart and Warren Rudman concluded that as a consequence of a coordinated terrorist attack, because of the lack of replacement parts for aged or customized equipment, “acute [power] shortages could mandate rolling blackouts for as long as several years.”

Unprecedented electric power grid failures, information networks under assault by computer viruses and hackers, large-scale transportation systems and water supplies open to terrorist attack, even the prospect of electronic voting exposed to all manner of fraud and undetected error: everywhere our critical infrastructures are vulnerable, “brittle,” and less robust than we had thought.