09/12/2012 06:26 pm ET Updated Nov 12, 2012

11 September Afterthoughts

An article, "The Terrorism Delusion: America's Overwrought Response to September 11," by John Mueller and Mark G. Stewart in the current edition of International Security, postulates that the terrorist threat to the United States is not nearly as great as we think. They provide extensive data to back this claim.

Is this correct? What is more important to me is not whether the article's conclusions are right or wrong, but rather that we should be reminded of the need to re-examine such events at intervals to make sure that we have drawn proper conclusions and taken away lessons that might help us avoid similar outcomes in the future.

Time has not lessened the personal wounds for those who lost loved ones 11 years ago, nor has it diminished the outrage for the rest of society. There is no better place to witness this than in the Pentagon. Anyone working there will tell you that 9/11 permanently altered the psyche of the building's occupants. But if one were to conduct a detached analysis, the more devastating effect on the nation was in resources, which includes, by some estimates, more than $4 trillion spent on the war against terror in all its aspects. Add to this the deaths of more than twice as many members of our armed forces than died on 11 September 2001 and we have a completely new calculus.

It is impossible to know everything that was in the mind of Osama bin Laden as he planned the attacks, but I suspect that if he were offered a choice of either killing 3,000 Americans or leveling a significant blow to the U.S. economy, he might have chosen the latter, at which point the target might have changed. Imagine the blow to New York, and secondarily, to the rest of the country, if bin Laden's minions had managed to make impassable New York's bridges and tunnels. Or, he might have decided that a more central target would have been worth the greater risk of failure. The Trade Center was on Manhattan's periphery. Striking the Empire State and Chrysler Buildings could have completely clogged central Manhattan and resulted in even greater losses in lives and commerce.

The timing of such attacks is also critical. We worry about attacks designed to correspond to national holidays and other prominent events. Is this really the most serious possibility? What if, instead, an attack were held in readiness and then launched shortly after the 2008 economic meltdown? What would have been the result of a second massive insult to the economy? Could such an attack have plunged us into deep depression?

And then, there is the question of why we have been spared another attack. There is no doubt that our heightened vigilance, magnified through the efforts of the nation's armed forces, intelligence agencies, and police departments, has been critical to keeping us safe. Is that all? Is it possible that our recent wars have contributed to our safety in a way not at all like that which our military or congresspeople would have us believe?

Our nation has lived through other terrorist attacks, the most serious of which were generally not on American soil (although we should not forget Oklahoma City or the first Trade Center bombing). Marines in Beirut, soldiers in Riyadh, sailors on board the U.S.S. Cole, the passengers over Lockerbie, and personnel of two of our African embassies were all among the tragic victims of terrorist acts. Could it be that the greatest difference between those events and September 11 is not that the latter was in the homeland, but, rather, the response? Did the violent nature of our response help to avoid further attacks?

There is no question that terrorists can be difficult or impossible to deter. But what if we instead deterred their patron states? Are the Irans of the world telling their surrogates that they don't want to potentially end up like Iraq and Afghanistan? Have they threatened to end funding and sanctuary for terrorists who feed off them should unsanctioned attacks occur? If that were the case, then even what would have appeared to be a totally wrong-headed effort like the invasion of Iraq might have had some beneficial effect by scaring the heck out of the state sponsors of terrorism. In that case, we should at least appear ready to mete out the kind of punishment we administered in Iraq and Afghanistan, even if we don't have any real intention of doing so. On the other hand, maybe initial shock and awe are enough to do the job without the follow-up costs of invasion. Or is this theory completely wrong?

Our first response to this anniversary should be, and will always be, to register the profound sadness for the victims of such an insane and cowardly act. But we should always be ready to look at the lessons of such an event. When might we expect another such attack? What are the most potentially devastating targets? How do we prevent another attack? We can never revisit such questions too often.