Pathogens as Weapons: The International Security Implications of Biological Warfare

Biological weapons have become one of the key security issues of the twenty-first century. ¹ Three factors that first emerged in the 1990s have contributed to this phenomenon. First, revelations regarding the size, scope, and sophistication of the Soviet and Iraqi biological warfare programs focused renewed attention on the proliferation of these weapons. ² Second,the catastrophic terrorist attacks on September 11, 2001, and the anthrax letters sent to media outlets and Senate offices in the United States during the following month, demonstrated the desire of terrorists to cause massive casualties and heightened concern over their ability to employ biological weapons. ³ Third, significant advances in the life sciences have increased concerns about how the biotechnology revolution could be exploited to develop new or improved biological weapons. ⁴ These trends suggest that there is a greater need than ever to answer several fundamental questions about biological warfare: What is the nature of the threat? What are the potential strategic consequences of the proliferation of biological weapons? How effective will traditional security strategies such as deterrence and arms control be in containing this threat? How do answers to these questions inform policies to reduce the danger of biological weapons?

A rich literature already exists on the history and capabilities of biological weapons. ⁵ In addition, the security studies community has begun to pay increased attention to the threat posed by these weapons. ⁶ Few attempts have been made, however, to apply theories from the field of security studies to assess the broader international security implications of biological weapons. ⁷ Previous studies addressed the potential lethality of biological weapons and concluded that state or terrorist use of these weapons in indiscriminant attacks on indefensible civilian populations represents the primary danger. ⁸ Biological weapons, however, possess other attributes that pose less obvious but more insidious threats to international security. These destabilizing features are mutually reinforcing and make biological weapons even more dangerous than suggested by assessments based solely on potential lethality.

The article begins with an examination of the major characteristics of pathogens as weapons. The next four sections assess the security implications of biological weapons in four key areas of concern for international security—proliferation, deterrence, civil-military relations, and threat assessment—and suggest the following conclusions. First, it is extremely difficult to prevent the spread of biological warfare capabilities to actors motivated by a desire to challenge the status quo. Second, biological weapons do not confer the deterrent benefits associated with nuclear weapons and pose special difficulties for states seeking to prevent their use. Third, the intense secrecy that shrouds biological warfare programs impedes civilian control over them. Fourth, states tend to have flawed assessments of the biological warfare capabilities and intentions of their opponents. A common theme throughout this article is that secrecy produces a variety of destabilizing effects: Not only does it impede verification, but it also undermines deterrence, hinders civilian oversight, and significantly complicates threat assessments. ⁹ After addressing potential objections to this analysis, I offer several policy prescriptions for reducing the biological weapons threat.

Pathogens as Weapons

Modern biological weapons are designed to disseminate pathogens or toxins in an aerosol cloud of microscopic particles that can be readily inhaled and retained in the lungs of the exposed population. ¹⁰ These aerosols are most effective when composed of particles ranging from 1 to 10 microns that can stay airborne longer and cause more severe cases of disease. ¹¹ Aerosols are tasteless, odorless, and invisible, thus facilitating clandestine attacks. They can be generated either by bomblets loaded into cluster bombs or missile warheads or by spraying devices that are mounted on aircraft, helicopters, cruise missiles, ships, or vehicles, or that are carried by hand. ¹² The key drawbacks to biological weapons include their delayed effects; their sensitivity to environmental and meteorological conditions, which could result in uncertain area coverage and effects; the risk of infecting friendly forces; and the...