And that's why one of the most intriguing concepts in counterterrorism today is called "resilience" -- preparing for terrorist attacks and minimizing their impact when they happen.
Terrorists aim to damage their opponents partly by provoking reactions bigger than the original attack. Osama bin Laden spent less than half a million dollars on the Sept. 11, 2001, attacks in New York and Washington, but he caused billions in damage by prompting a shutdown of financial markets, air travel and other chunks of the U.S. economy -- not to mention the war in Afghanistan and the other counterterrorist campaigns that ensued.
But if a society is prepared for terrorist attacks, makes sure its citizens know how to react when they happen, and protects its transportation, communications and utilities networks from being paralyzed by local disruptions, the impact of terrorism is reduced. It's still a problem, but it's no longer an existential threat.
The greatest danger from most of those bombs may be from secondary explosions, airborne contaminants or radiation. Jumping into your car to flee merely exposes you to more risks, and when thousands of people try to evacuate, they choke the roads, cause traffic accidents and impede emergency responders.
But not everybody knows that. A 2007 survey found that in the event of a "dirty bomb," a conventional explosion that spreads radioactive material, 65% of people said their first impulse would be to flee. Flynn talked last year with New York City firefighters and said some of them didn't know whether they should tell people to evacuate or seek shelter in the event of an explosion. ("The policy of the department is clear, and that's shelter in place," responded Joseph W. Pfeifer, New York's assistant fire chief for counterterrorism. "We've trained everyone on that.... The real challenge is educating the public.")
"Nobody ever told the emergency responders what to do," he said.
In the case of a nuclear explosion, a study by Stanford professor Lawrence Wein estimated that a small nuclear device in Washington, D.C., could kill 120,000 people if most people sought shelter in buildings -- but 180,000 if most people tried to evacuate.
Be pretty if you are,
Be witty if you can,
But be cheerful if it kills you.
If you're so evil, eat this kitten!