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Did the U.S. Overreact to the 9/11 Attacks? Undoubtedly

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


A decade ago I was wrestling a paragraph in my home office when my wife called out from another room, alarm in her voice. The music station she was listening to had interrupted a song to announce that a plane had flown into the World Trade Center. We turned on the television, which had a live shot of smoke billowing from one of the Twin Towers, just in time to see a jet smash into the other tower.

On impulse, I ran up a hill near the house, from which you can see the Manhattan skyline 30 miles south. From the hilltop, I could see only smoke where once the Twin Towers had stood. Stunned, I thought about my son and daughter, then eight and six years old. I had hoped that they would grow up in a relatively peaceful world. Was I wrong?

I still believe we're headed toward a less violent future—with the proviso that the U.S. learns how to deal with terrorism in a more rational manner. In a previous post, I presented examples of iatrogenesis—ostensible cures for diseases and other problems that end up doing more harm than good. To my list, which included religion, communism and psychiatric drugs, I should perhaps add recent U.S. counterterrorism programs. Yes, the U.S. had to respond to al Qaeda's horrific attack, but we clearly overreacted.


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This conclusion emerges from risk-benefit analyses of post 9/11 counterterrorism efforts by John Mueller, a political scientist at Ohio State University, and Mark Stewart, a civil engineer and authority on risk assessment at University of Newcastle in Australia. In the most recent issue of Homeland Security Affairs, Mueller and Stewart noted that after 9/11, U.S. officials had warned that we could expect many more such attacks, and that terrorism represented an "existential" threat, as the former Secretary of Homeland Security Michael Chertoff had put it.

These fears triggered a surge in counterterrorism spending. Mueller and Stewart estimate that the response to 9/11 by federal, state and local governments as well as private corporations has totaled $1 trillion. The costs include measures such as beefed up intelligence, hardening of facilities and more robust airport screening but exclude the wars in Afghanistan and Iraq. Even granting that terrorism evokes powerful emotions and hence deserves more attention than other dangers, Mueller and Stewart contended, "a great deal of money appears to have been misspent and would have been far more productive—saved far more lives—if it had been expended in other ways."

Mueller and Stewart noted that, in general, government regulators around the world view fatality risks—say, from nuclear power, industrial toxins or commercial aviation—above one person per million per year as "acceptable." Between 1970 and 2007 Mueller and Stewart asserted in a separate paper published last year in Foreign Affairs that a total of 3,292 Americans (not counting those in war zones) were killed by terrorists resulting in an annual risk of one in 3.5 million. Americans were more likely to die in an accident involving a bathtub (one in 950,000), a home appliance (one in 1.5 million), a deer (one in two million) or on a commercial airliner (one in 2.9 million).

The global mortality rate of death by terrorism is even lower. Worldwide, terrorism killed 13,971 people between 1975 and 2003, an annual rate of one in 12.5 million. Since 9/11 acts of terrorism carried out by Muslim militants outside of war zones have killed about 300 people per year worldwide. This tally includes attacks not only by al Qaeda but also by "imitators, enthusiasts, look-alikes and wannabes," according to Mueller and Stewart.

Defenders of U.S. counterterrorism efforts might argue that they have kept casualties low by thwarting attacks. But investigations by the FBI and other law enforcement agencies suggest that 9/11 may have been an outlier—an aberration—rather than a harbinger of future attacks. Muslim terrorists are for the most part "short on know-how, prone to make mistakes, poor at planning" and small in number, Mueller and Stewart stated. Although still potentially dangerous, terrorists hardly represent an "existential" threat on a par with those posed by Nazi Germany or the Soviet Union.

In fact, Mueller and Stewart suggestedin Homeland Security Affairs, U.S. counterterrorism procedures may indirectly imperil more lives than they preserve: "Increased delays and added costs at U.S. airports due to new security procedures provide incentive for many short-haul passengers to drive to their destination rather than flying, and, since driving is far riskier than air travel, the extra automobile traffic generated has been estimated to result in 500 or more extra road fatalities per year."

The funds that the U.S. spends on counterterrorism should perhaps be diverted to other more significant perils, such as industrial accidents (one in 53,000), violent crime (one in 22,000), automobile accidents (one in 8,000) and cancer (one in 540). "Overall," Mueller and Stewart wrote, "vastly more lives could have been saved if counterterrorism funds had instead been spent on combating hazards that present unacceptable risks." In an e-mail to me, Mueller elaborated:

"The key question, never asked of course, is what would the likelihood be if the added security measures had not been put in place? And, if the chances without the security measures might have been, say, one in 2.5 million per year, were the trillions of dollars in investment (including overseas policing which may have played a major role) worth that gain in security—to move from being unbelievably safe to being unbelievably unbelievably safe? Given that al Qaeda and al Qaeda types have managed to kill some 200 to 400 people throughout the entire world each year outside of war zones since 9/11—including in areas that are far less secure than the U.S.—there is no reason to anticipate that the measures have deterred, foiled or protected against massive casualties in the United States. If the domestic (we leave out overseas) enhanced security measures put into place after 9/11 have saved 100 lives per year in the United States, they would have done so at a cost of $1 billion per saved life. That same money, if invested in a measure that saves lives at a cost of $1 million each—like passive restraints for buses and trucks—would have saved 1,000 times more lives."

Mueller and Stewart's analysis is conservative, because it excludes the most lethal and expensive U.S. responses to 9/11. Al Qaeda's attacks also provoked the U.S. into invading and occupying two countries, at an estimated cost of several trillion dollars. The wars in Afghanistan and Iraq have resulted in the deaths of more than 6,000 Americans so far—more than twice as many as were killed on September 11, 2001—as well as tens of thousands of Iraqis and Afghans.

The U.S. has also damaged its moral reputation by imprisoning without trial, torturing and assassinating alleged terrorists even in nations, such as Pakistan and Yemen, with which we are not at war. All these actions have helped arouse rather than quell anti-American sentiment among Muslims and others. In spite of its economic woes, the U.S. has more than doubled its annual defense spending in the past decade, which is now almost equal to that of all other nations combined.

Osama bin Laden, who was finally killed by U.S. forces in June, never again pulled off an attack as cataclysmic as the one on 9/11. But he didn't have to, because we—the U.S.—wreaked so much destruction ourselves. In 2004 bin Laden gloated that he was "bleeding America to the point of bankruptcy," the same strategy with which he and other jihadists—with U.S. backing—drove Soviet troops from Afghanistan.

Mueller and Stewart—who present a detailed critique of counterterrorism policies in Terror, Security and Money: Balancing the Risks, Benefits and Costs of Homeland Security (Oxford University Press, 2011)—noted that a major obstacle to more rational policies is a shortage of "that oxymoronic commodity," political courage. But a few politicians have dared to question the view of terrorism as a peril to civilization. In 2007 New York City Mayor Michael Bloomberg said that people are more likely to be killed by lightning than terrorism. "You can't sit there and worry about everything," Bloomberg exclaimed. "Get a life.

Actually, according to Mueller and Stewart, Americans' annual risk of dying from lightning, at one in seven million is only half the risk from terrorism. Bloomberg's comments nonetheless give me hope that as the traumatic memory of 9/11 recedes our leaders will begin devising rational, non-iatrogenic policies toward terrorism and other security threats. After all, as Mueller has pointed out (pdf), we're already living in period when casualties from warfare are extraordinarily low, by historical standards. So I still hope—I believe!—that my children will live to see a day when lightning poses a greater danger than terrorism or war.

Table from "Hardly Existential," by John Mueller and Mark Stewart, Foreign Affairs, April 2, 2010