"You never hear the one that gets you," snipers say. A bullet traveling faster than sound will impact and wreak its damage before the brain can process what is happening. That little piece of military lore ran through my mind upon reading the Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack. An April, 2008 update of a 2004 report, this report outlines the near-instantaneous effects that an electromagnetic bomb would likely have on the nation's power, telecommunications, banking/finance, fuel, and other systems.
Tightly coupled systems are particularly vulnerable to breakdown, catastrophic failure, and disruption. This is one lesson from the recent subprime-induced meltdown of our financial system. A lengthy breakdown of a country's electrical systems, shutting down everything from the power grid to computers to electronics systems in automobiles, trains, and planes, would have significantly greater impacts than the financial crises we currently bemoan.
The attacks in Mumbai are a stark reminder that rogue groups possess the will to disrupt modern society. The threat assessments from the recent reports cited above suggest that it is only a matter of time before they also possess the means. Research is under way to protect vulnerable systems and the cost of hardening new components and systems is not prohibitive. The cost of retrofitting and hardening existing systems is significant, and that leaves much of our infrastructure vulnerable--and almost all of us unprepared.