What, exactly, is a WMD?

The ominous expression "weapons of mass destruction" conjures up images of mushroom clouds. Other dire possibilities include lethal gases or genetically engineered infectious agents.

Pre-war administration rhetoric was designed to give the impression that huge caches of battle-ready WMDs littered the Iraqi countryside. After U.S. occupation forces failed to locate any WMDs of any variety, defenders of the invasion sought refuge in metaphor: it was Saddam himself who was the "weapon of mass destruction," they insisted, and thus any weapons in his possession would be considered WMDs.

The Justice Department, perhaps taking its cue from such fanciful, after-the-fact justifications for the invasion of Iraq, has embraced a similar definition of WMDs. On April 12, Deputy Attorney General James Comey unveiled indictments against three individuals accused of "Conspiracy to use weapons of mass destruction in a terrorist attack" against several U.S. targets, including the Prudential Corporate Plaza, the New York Stock Exchange, and Citigroup Center. The alleged plot, Comey explained in a press conference, was what led to the August 1,2004 decision to raise the terrorism threat level from "'elevated" to 'high" for parts of New York, New Jersey, and Washington, D.C."

"What specific types of WMD are [the accused terrorists] alleged to have plotted to use?" inquired a reporter. Comey replied that the indictment "speaks only in terms of improvised explosive devices"--which is to say, common bombs, not nuclear, chemical, biological, or radiological weapons. When a follow-up question referred to those types of uncommon weaponry, Comey stated: "We have not alleged that. But as you alluded to, a weapon of mass destruction in our world goes beyond that [definition] and includes improvised explosive devices."

While it's unwise to diminish the capacity for death and mayhem represented by improvised explosive devices in the hands of actual terrorists, it appears that the Bush administration's definition of WMDs includes any weapon of any sort employed by any nation or group the federal government considers a threat.