The government’s second grounding of crop dusting aircraft in the wake of the September 11th terrorist strikes on the Pentagon and World Trade Center is a chilling reminder that those devastating attacks may not be the worst that can happen. Before the strikes, the men believed to have been the perpetrators of the attacks visited a municipal airport in Florida and asked many questions about crop dusting aircraft. In addition, there is a possibility that some of the men connected to the attacks recently applied for and received licenses to drive trucks that haul hazardous materials.

Meanwhile, it has been known for some time that Osama bin Laden has been seeking to obtain chemical weapons. Although controversy surrounded President Clinton’s cruise missile strike on a Sudanese pharmaceutical plant, that administration maintained that the factory had links to bin Laden and had made chemical weapons. Recent satellite photographs of eastern Afghanistan have shown dead animals around an apparent laboratory used for experimentation with weapons of mass destruction (WMD). All of these developments raise the ugly, but very real, possibility that terrorists-especially bin Laden and his organization-might attempt a cataclysmic strike on the United States with such “super weapons.”

In the future, that possibility is not remote. Department of Defense officials and publications have long warned of the potentiality for such attacks. The threat of an attack using nuclear, biological or chemical weapons was best summed up by Deborah Lee when she was an assistant secretary of defense during the Clinton administration, “Doubts about the timing and location of possible terrorist attacks sit uneasily alongside the almost certain possibility that attacks against the U.S. homeland will eventually occur. Counterterrorism specialists define the problem not as a question of if but of when and where such attacks will take place.” A 1997 Defense Science Board study, commissioned by the Office of the Secretary of Defense, referring to strikes by terrorists using WMD wrote the “risk of attack on U.S. soil [is] both likely and becoming more easily carried out.”

Of the three types of weapons, chemical and biological agents are probably the most likely to be used in an attack (nuclear bomb-making requires sizeable infrastructure and fissionable material that is under international control). Sprayers, including crop dusting aircraft, are the most likely means of delivering those agents. Another report by the Department of Defense on the proliferation of WMD, described the threat: “If need be, crop duster aircraft and simple spray generators can be readily adapted for delivery of a variety of agents. The quantities of chemical agent required are relatively small when compared to industrial production of similar commercial chemicals, which poses significant problems for detection. The low technology required lends itself to proliferant and even potential terrorist use.”

Chemical and biological agents are fairly easy to produce using readily available commercial materials and technologies. Such agents can be produced in commercial facilities, including dairies and wineries for biological weapons and fertilizer factories and chemical and pharmaceutical plants for chemical weapons. Even if produced overseas, small quantities of agents needed would be easy to smuggle across the thousands of mile of U.S. borders. U.S. intelligence might not be able to detect and interdict such shipments or even detect the activities of the potential perpetrators (a lesson learned from attacks on September 11).

Of the two types of weapons, biological agents are much more lethal, but also more difficult to make into weapons, than chemical agents. Chemical weapons are relatively easy to make and use and would probably be the terrorists’ first choice. In the future, however, if terrorist groups recruit competent scientists and engineers, even biological weapons may become a threat to the U.S. homeland. If employed properly under the right environmental conditions, chemical weapons could kill thousands or tens of thousands of people and biological weapons could kill tens or hundreds of thousands.

Mitigating the effects of such catastrophic attacks also would be difficult. A major problem is detecting such attacks before it is too late. Also, police, fire, paramedical and hospital resources would probably be easily overwhelmed. Currently, a shortage exists of vaccines and antidotes for the major biological and chemical agents. It would be cost-prohibitive to provide protective suits and masks for every American citizen.

If terrorists (including bin Laden himself) begin to try to top the spectacular attack on September 11, the only thing more horrible than that strike--the use of WMD--could become a horrible reality. In the short-term, the U.S. government needs to rapidly beef up human intelligence capabilities to get better warning of any such attack and to continue to provide training, equipment, and medical supplies (for example, detection devices, protective masks and suits, and vaccines and antidotes) for local emergency workers. In the long-term, after the dust settles, the U.S. government must ask itself hard questions about what motivates terrorist groups to attack U.S. targets in 47 percent of the world’s terrorist incidents. Perhaps the U.S. government could initiate changes in its foreign policy that would make the United States less of a target for such attacks.