The United States government has been in a flurry of activity since 9/11. During the past year, in the words of the Department of Homeland Security website, the government has:

• Deployed more than 4,000 FBI special agents and 3,000 support staff to the international investigation of the September 11 terrorist attacks—the largest criminal investigation in history.
  
  
• Deployed more than 9,000 National Guard troops to help secure the nation's airports.
  
  
• Dispensed antibiotics to thousands of people potentially exposed to anthrax mail attacks.
  
  
• Acquired more than a billion doses of antibiotics and signed agreements for the procurement of the smallpox vaccine.
  
  
• Provided round-the-clock security at 348 dams and reservoirs and 58 hydroelectric power plants, including the Hoover, Grand Coulee, Glen Canyon, and Shasta dams.
  
  

That's an impressive response—and only a small part of a very long list of measures. The $10 billion-plus for these protections has been money well spent. Terrorism is not a fad that extremists will soon tire of. It's been brewing for decades. Anthony Lake, in Six Nightmares: Real Threats in a Dangerous World and How America Can Meet Them (Little, Brown, 2000), details the recent history of U.S.-based terrorists (such as Aryan Nation) turning to chemical weapons of mass destruction.

Internationally, the problem is more frightening. One reason the Bush administration is making noises about invading Iraq is that nation's public acknowledgment of its chemical weapons reserve.

In the 1990s, Iraq declared it had 2,245 gallons of anthrax, 5,125 gallons of botulinum toxin, and 4 metric tons of the nerve agent VX—all of which combined could kill everyone on Earth several times over. Since Saddam Hussein turned away weapons inspectors ...