Review of

The Problem of Biological Weapons

Stockholm, Sweden: Swedish National Defense College, 2004, 206 pp.

“The age of bioterrorism is now,” the Washington Post said in January 2005. Many politicians, policymakers, and scientists agree, and so billions of dollars are being spent on biodefense R&D. A dramatic increase in classified threat-assessment research is imminent, including the exploration of potential new bioweapons agents and technologies. Senate Majority Leader Bill Frist says that bioterrorism is “the greatest existential threat we have in the world today” and calls for a biodefense R&D effort that “even dwarfs the Manhattan Project.” Many others agree.

Milton Leitenberg does not agree. He believes that the threat of catastrophic bioterrorism has been grossly and irresponsibly exaggerated. He says that faulty threat assessments are legion, that the bioweapons problem is larger and more complex than the focus on bioterrorism suggests, and that current U.S. policies are making the problem worse.

Leitenberg, a senior research scholar at the University of Maryland’s Center for International and Security Studies, is a bioweapons and arms control expert with nearly 40 years of experience. In his provocative new book, The Problem of Biological Weapons, he presents what he considers a more reasoned, comprehensive, and evidence-based assessment of the bioweapons threat. Focusing on events of the past 15 years, Leitenberg examines national bioweapons programs, bioterrorism, international efforts to bring bioweapons under control, and current U.S. policies and activities. He concludes that the primary threat today is not bioterrorism but rather the proliferation of bioweapons programs among states.

Widespread U.S. concern about bioterrorism first emerged in 1995 after the Aum Shinrikyo cult released sarin (a chemical nerve agent) in the Tokyo subway system and was then found to have made earlier, unsuccessful attempts to use bioweapons. Nonetheless, a dramatic increase in biodefense funding didn’t occur until after the 9/11 terrorist attacks demonstrated that some terrorists were willing to kill unlimited numbers of people. The anthrax attacks that followed shortly thereafter sealed the case for the biodefense R&D boom.

Leitenberg agrees that terrorists are interested in bioweapons, but he concludes from a detailed review of the evidence that there is little or no trend indicating that terrorist capabilities are improving. Whereas others see Aum Shinrikyo as demonstrating the ease with which nonstate actors could develop and use bioweapons, Leitenberg sees the opposite: a group incapable of mounting a successful bioweapons attack despite significant interest and major effort. He says that al Qaeda remains far behind Aum in its capabilities. Finally, he notes that the U.S. government maintains that someone closely connected to the U.S. biodefense program probably perpetrated the 2001 anthrax attacks. As for damage assessments, Leitenberg says that those used in recent planning exercises are unreasonable and reflect only the most extreme and least likely consequences of worst-case scenarios. His conclusion is clearly stated: “A terrorist use of a BW agent is best characterized as an event of extremely low probability, which might—depending on the agent, its quality and its means of dispersion—produce high mortality.”

State-sponsored bioweapons

Leitenberg is much more concerned about the proliferation of state-sponsored bioweapons programs. He calls this “the most serious threat in the long term,” because it would undermine the norm against bioweapons, lead to their widespread dissemination, and increase the danger that nations and terrorists will use them.

The reasons for Leitenberg’s concern are threefold. The countries participating in the Biological and Toxin Weapons Convention (BWC) have failed to seriously confront the bioweapons problem, first by failing to enforce compliance with the convention in the face of strong suspicions and even clear evidence of violations, and second by failing to develop better preventive measures, including a strong BWC verification protocol. He says that the United States is largely responsible for the latter failure, acting primarily to protect sensitive and sometimes questionable bioweapons-related R&D activities.

Although these failures have weakened the BWC and made it easier for nations to pursue bioweapons programs, Leitenberg argues that a third factor—the current expansion of U.S. biodefense R&D—may actually motivate such pursuit. In the final two chapters of his book, he discusses the difficulty of distinguishing offensive from defensive intent in national bioweapons-related programs. He notes that the BWC prohibits the development of bioweapons and weapons agents but does not mention research. Yet it is widely recognized that research on dangerous pathogens can be used not only for beneficial, defensive purposes but also to cause harm. Further, the boundary between research and development has always been unclear and is only becoming more so. Leitenberg disputes U.S. claims about the types of research activities that are permitted under the BWC and argues that it is the aggregate level of activity rather than the details of individual projects that raises cause for concern. Indeed, he shows that it is nearly impossible to determine the intent of an individual research project without knowledge of the overall program within which it is embedded. Finally, he emphasizes that the problem of determining intent is most difficult when research is classified, as is increasingly the case for growing U.S. threat-assessment activities. Leitenberg concludes that the current U.S. approach to biodefense and nonproliferation increases international suspicion and could lead to a dangerous cycle of escalating and secretive R&D activity. At the very least, the United States is “facilitat[ing] the ability of other nations to justify secret programs following the example already provided by the United States.”

Leitenberg’s critics charge that he fails to recognize that past experiences and current trends in bioterrorist activity aren’t useful indicators of future events. However, these critics routinely cite Aum Shinrikyo and base their own threat assessments and attack scenarios, including large urban aerosol releases and genetically engineered pathogens, on their knowledge of old national offensive programs and on trends in science and technology. Clearly, for both Leitenberg and his critics, consideration of past experiences and trends is an important part of threat assessment.

A Washington Post article in December 2004 cited broad agreement among bioweapons experts that significant “technical obstacles [exist] that would confound even skilled scientists” who attempted to develop bioweapons. This would seem to support Leitenberg’s arguments. However, these experts also asserted that the life sciences revolution makes it all but inevitable that terrorists will eventually be able to launch mass-casualty biological attacks. Leitenberg admits that advances in science and technology may increase terrorist capabilities in the future but says little more on this topic than to point out that experts have been saying this for nearly 20 years and that states are much more able and likely to exploit these advances. Although technically correct, the brevity of Leitenberg’s response indicates a failure to more thoroughly consider factors that may in fact increase the likelihood of bioterrorist attacks.

The fundamental problem facing analysts and decisionmakers is the great level of uncertainty surrounding the bioweapons problem. How and when might terrorists achieve breakthrough capabilities? How rapidly are their capabilities likely to advance? Most public threat assessments parse this uncertainty by assuming a 100 percent likelihood of attack over some unspecified length of time. They ignore factors that affect likelihood and focus on the worst consequences of worst-case scenarios. They infer capabilities from intentions and vice versa, and tend to assume that today’s terrorists will think and act like yesterday’s governments. Leitenberg focuses on assessing likelihood based on trends in terrorist capabilities, but these are hard to discern, given a meager data set. Meanwhile, he largely ignores vulnerabilities and consequences. Leitenberg is probably correct that the likelihood of a significant bioterrorist attack is low and will be so for some time. However, it is not zero, and it may be greater than he thinks.

Forging policy

What are we to do? Responsible security decisions require thorough consideration of the likelihood and the potential consequences of a security threat. They also require thorough consideration of the trade-offs associated with various possible responses. The great value of Leitenberg’s approach is its insistence on examining critical aspects of the bioweapons threat that are largely being ignored today.

We do need rigorous, realistic, and comprehensive threat assessments that consider all relevant factors and their interactions and associated uncertainties. These factors include vulnerabilities; the properties of threat agents; the current state of technology; the capabilities, motivations, and intentions of attackers (based on current knowledge and identified trends); and the likely effects of various policy choices. Threat assessments like these will help decisionmakers identify and sustain balanced and prioritized strategies for reducing bioterrorist and broader bioweapons threats. In a few cases, the nation might decide that a particular biological attack could have such extreme consequences that it must be prepared for even if its likelihood is low. Such decisions must still be informed by solid and broadly acceptable threat assessments if preparedness efforts are to be sustainable, and policymakers will still have to consider trade-offs in order to identify best strategies. The current crisis management approach to decisionmaking instead exhibits rapidly changing priorities, underemphasizes nonproliferation and other prevention efforts, tends to compete with other public health and scientific research needs, and generally ignores potentially serious negative consequences.

Leitenberg’s book also demonstrates that the new problem of bioterrorism doesn’t eliminate the old problem of state bioweapons programs and reminds us of all the trade-offs that must therefore be considered. He quite rightly raises many concerns about current U.S. policies, to which he could have added the apparent U.S. interest (shared with some other nations) in developing incapacitating biochemical weapons. It should be obvious that governments make national security decisions based in part on their perceptions and uncertainties about the activities of others. However, most U.S. policymakers are not giving serious consideration to the negative consequences of current policies and actions.

As Leitenberg discusses, one of the areas where such consideration is most critical is in bioweaponsrelated R&D. It is essential that U.S. activities not make proliferation among states or terrorist breakthroughs more likely. In practical terms, this means first developing strong internal and external oversight and review mechanisms for bioweapons-related R&D projects and programs. Self-regulation by scientists and funding agencies, although critical, is not enough to provide broad reassurance and accountability. It is neither a fair nor an effective substitute for government responsibility. Second, effective action must be taken toward the difficult goal of implementing universal biosafety and biosecurity standards. Third, transparency must be the dominant principle guiding biodefense R&D. Transparency is required both for biomedical advance and to reassure concerned parties at home and abroad. However, transparency cannot be universal, or we will risk revealing critical information that could aid bioweaponeers. Thus, reasonable, effective, and well-defined mechanisms for restricting access to critical information must be developed, consistently implemented, and made publicly known.

All of these arguments apply most especially to threat-assessment and -characterization research programs, which run significant risks of stimulating and justifying the threats they are supposed to defend against and even of creating new problems that must then be solved. Thus, the United States must establish mechanisms for identifying the most critical gaps in knowledge and for strictly limiting threat-assessment research to filling those gaps. Threat-assessment activities must not undermine international efforts to control bioweapons.

Finally, no defensive wall will be high enough by itself to protect the United States from the horrors of bioweapons. All U.S. actions must reinforce the international norm against bioweapons. Although it makes sense to prepare for the possibility of a bioweapons attack, it is irresponsible to loudly assert the certain inevitability of catastrophic bioterrorism. Such talk will undermine the nation’s ability to minimize panic and ensure public trust and cooperation in the event of an attack. It also promotes malevolent interest in and public tolerance of bioweapons. Likewise, it is irresponsible to engage in activities that are likely to spur proliferation, whether knowingly or thoughtlessly. There must be no pursuit of biological or biochemical weapons of any kind, for any reason. Today more than ever, nations need to exercise responsible and collective restraint. Governments must also take greater international action in support of nonproliferation and other means of prevention. Such action, forged around common support for the norm, is essential for its maintenance and thus for reducing the bioterrorist threat. In all of these areas, the United States should be setting an example and leading the way. The scientific community, occupied today with concerns about dual use and scientific responsibility, can do much to help.

Cite this Article

Pearson, Alan. “Bioweapons.” Issues in Science and Technology 21, no. 3 (Spring 2005).

Vol. XXI, No. 3, Spring 2005