(Please see update below.) The Atlantic's Jeffrey Goldberg has written recently to criticize attempts by John Mueller and others to put terrorist attacks "into perspective." Mueller has compared the number of people killed in bombings, hijackings, and similar deliberate terrorist assaults with, say, the number who drown in bathtubs each year. His point is to ask whether terrorism should be considered an "existential threat," as many people argued after 9/11, and whether the "global war on terror" has justified the financial costs and the strains on Constitutional liberties we have seen in the past decade.
Jeff Goldberg points out, correctly, that not all risks or deaths are the same, and that there is a big difference between an accidental tragedy and a purposeful assault. Roughly as many Americans die from cancer every two days (~3000) as died from terrorism on September 11, 2001, but we rightly regard these tolls in very different ways. He then makes another point I agree with, but from which I draw a different conclusion from his own:
Deaths caused by terrorism, on the other hand, can have a profound effect on society and the economy. The deaths of ten people in bathtub accidents won't cause people to fear leaving their homes; but imagine the impact of 10 deaths in a terrorist bombing of a shopping mall, or a movie theater. And imagine if it happens more than once. The economic impact could be devastating; the impact on the emotional health of parents and children would be profound....
And consider the impact of terrorism on the Constitution, and on our collective self-conception as an open and free society. Just look at the stress placed on our constitutional freedoms by 9/11. ...Terrorism's capacity to affect the functioning of our society, and to fray the bonds that tie citizens together, and to cause mass-casualty events that would dwarf 9/11, makes it a unique and dangerous challenge.
It is precisely because people and societies can panic about terrorist threats -- and often did ten years ago -- that both the threats and the panic are worth doing everything possible to minimize. Anyone who has ever thought about the long-term effort against terrorism realizes that the threat of attacks will never completely go away. If a society is large, open, and diverse, that is simply impossible. It's like "eliminating" crime, or evil. Or like eliminating the chance of another Columbine-style schoolyard shooting, which is "terrorism" in every way except the conventional name. All of these deserve the best possible preventive efforts, but "best possible" will never mean perfect.
Therefore the next step is to avoid magnifying the terrorizing effects of a murderous attack, and instead to do what we can to keep it in perspective. Parents send their children to school every day, even though we know that some day there will be "another Columbine" (or "another Virginia Tech" or, away from the schoolyard, "another Tucson"). School shootings are absolute evil, which we should take far more urgently than we do. But when they occur, the usual response is to try to dampen rather than intensify a reaction of generalized fearfulness and panic. That is how we should react to something called "terrorism" as well. Which is what Mueller was trying to do.