What is more telling about the attacks is that they were carried out with conventional, albeit extreme weapons, not the nightmare chemical, biological, radiological and nuclear devices that have been at the forefront of much of the country's domestic contingency planning for most of the past seven years.
Ever since 1995's bombing of the Alfred Murrah Federal Building in Oklahoma City, the thrust of U.S. counter-terrorism has been toward preparing for and deterring attacks involving weapons of mass destruction. The presumed wisdom among policy-makers, defense officials and intelligence analysts was that terrorism was on an escalatory spiral, which due to increased knowledge pertaining to chemical, biological or nuclear agents in the wake of the collapse of the Soviet Union and the Persian Gulf War, would inevitably lead to a cataclysmic unconventional attack directly on American soil. Such thinking -- encapsulated in the oft repeated rhetoric of "its not a matter of if but when" -- led to the creation of a complex web of federal, state and local initiatives specifically tailored for worst-case scenarios and so-called "high consequence" events.
Basing U.S. counter-terrorism planning on this type of thinking was, and is, problematic for a number of reasons:
The events that shook the United States on Sept. 11 underscore the limited utility of the WMD logic with horrific clarity. The attacks directed against the World Trade Center and Pentagon were neither high-tech nor unconventional in nature, involving, in the final analysis, bombs -- albeit highly powerful ones. Just as critically, they demonstrated that conventional means are perfectly capable of causing mass carnage and driving home highly powerful political messages.
Above all, however, they exposed gaps in current U.S. terrorist threat and consequence management, much of which has stemmed from the misguided assumption that rudimentary conventional attacks represent a lesser contingency that can be easily dealt with in preparations for high-end WMD assaults.
Terrorists, although highly radical in their objectives, exhibit an overwhelming conservatism in the choice of their tactics, resorting in most instances to tried and tested methods that are known and whose consequences can be predicted relatively easily. In this way, terrorists act like a body of running water, tending toward the course of least resistance.
Even well-endowed organizations such as Bin Laden's al-Qaeda network have limited and finite financial and material resources at their disposal. This means that they are necessarily going to favor methods that are inexpensive, do not require a great deal of technical sophistication and which offer a reasonable guarantee of success. None of these facets apply to chemical, biological or nuclear weapons, particularly if the objective is to cause mass casualties.
Perhaps the clearest example of this was the 1995 sarin nerve gassing in Tokyo. Carried out by the Aum Shinriyko Cult -- an unprecedented terrorist group in terms of the technological sophistication and wealth at its disposal -- the attack represented the culmination of an elaborate five-year effort to develop a viable chemical and biological weapons capability.
When the assault occurred, however, it resulted in no more than 12 deaths, despite being carried out at the height of the rush hour on one of the world's busiest subway systems. This failing is indicative of the enormous obstacles that are inherent in weaponizing and dispersing chemical agents over wide areas to affect large numbers of people (something that applies equally to biological organisms -- Aum's attempts to disseminate anthrax slurries and botulinum toxin were equally as unsuccessful).
What does all this mean for U.S. counter-terrorism and homeland defense?
Most fundamentally, it suggests that Washington needs to reconsider where it is placing the bulk of its resources in terms of domestic contingency planning. Certainly one cannot ignore the possibility of a mass biological or chemical attack; the consequences of doing so in the event one actually occurred would be incalculable.
However, to emphasize this type of scenario at the expense of more probable conventional (or lower level unconventional) attacks represents neither good policy nor a judicious use of fiscal resources. A comprehensive and rational threat assessment of the scope and dimensions posed by the contemporary terrorist phenomenon is the only way to correct this imbalance -- something that has yet to occur (at least in any meaningful sense) within the United States. Addressing this gap is no longer merely an issue of academic interest; it is now one of critical national importance.
Chalk is a policy analyst specializing in national security and international terrorism issues in RAND Corporation's Washington, D.C. office.
This commentary appeared in San Diego Union Tribune on September 21, 2001