In September 2001, members of Al Qaeda — a fringe group within a fringe group and with grandiose visions of its own importance — managed, largely because of luck, to pull off a risky terrorist act that became the most destructive in history. Yet the United States has been reluctant to maintain that such a monumental event could have been carried out by a fundamentally trivial group, and it has greatly inflated Al Qaeda's importance. Some seasoned professionals even maintain that the tiny group presents an "existential" threat to the very survival of the US.
As a result, the US reaction to the attacks of Sept. 11 has been massively disproportionate to the threat that Al Qaeda has actually presented, either as an international menace or an inspiration to homegrown amateurs. Trillions of dollars have been expended and tens of thousands of lives have been snuffed out in distant wars in a frantic, ill-conceived effort to react to an event that, however tragic and dramatic, was not ultimately of far-reaching significance.
A standard cost-benefit analysis suggests that enhanced US domestic expenditures on homeland security since 9/11 would have to prevent one large attack per day to be cost effective. In fact, terrorists have been unable to detonate even a primitive bomb in the US since Sept. 11, and they have killed only a handful of people by gunfire.
The chance that an American will perish at the hands of a terrorist at present rates is 1 in 3.5 million per year. And extremist Islamist terrorism worldwide has claimed 200-400 lives per year outside war zones, which although tragic and regrettable, amounts to the yearly number of bathtub drownings in the United States.
Meanwhile, beyond uniting the world against its violent jihad, Al Qaeda central has done little except issue self-infatuated threats. Material seized when Osama bin Laden was killed last year reveals that its members have been primarily occupied with dodging drones, complaining about the lack of funds, and watching a lot of pornography.
The common extrapolation that terrorists could construct a nuclear bomb because they were able, mostly by thuggish means, to crash airplanes into buildings reflects how delusional and exaggerated the US perception of the Al Qaeda threat is.
Although the thousands upon thousands of Al Qaeda operatives once thought to be flourishing in the United States proved to be nonexistent, the quest to make that delusion more closely fit reality has impelled a massive expansion of domestic policing. As part of this, the FBI receives more than 5,000 "threats" a day. Only a tiny number of these have led to terrorism arrests, but the FBI continues to follow up all of them, expending huge amounts of money in what some in the Bureau call "ghost chasing."
If Sept. 11 was an aberration rather than a harbinger, anxieties in the US about terrorism should be receding. Yet 35 to 40 percent of Americans continue to profess worry, even after the death of bin Laden, that they or a family member might become a victim of terrorism, despite the microscopic odds.
The peculiar trauma of the Sept. 11 attacks as well as the perception that Muslim extremist terrorists are out to kill as many people as possible may be fueling this anxiety. In addition, US government officials continue to stoke fear, emphasizing what failed terrorist plotters had hoped to do instead of what they were realistically likely to have done.
Yet official alarmism has tapered off in recent years, and warnings that the country must brace itself for a large imminent attack are now rarely heard. Policymakers and the media now tend to respond to (and at times exacerbate) the fears of the public rather than create them.
Americans seem to have internalized their anxiety. A fundamental reassessment of the problem therefore seems unlikely, and the terrorism delusion may accordingly prove to be perpetual.