STANFORD, Calif.- For the past seven years, the United States has been negotiating a verification protocol to the Biological Weapons Convention of 1972, hoping to put teeth into the convention's ban on biological weapons production. The Bush administration recently rejected the latest draft of the protocol, viewing it as irredeemably flawed. This is a good time to ask what a new American strategy should be for security against biological threats. It is difficult to predict the likelihood or scale of biological attack. The right policy will provide benefits whether or not an attack occurs.

The first step is conceptual: we must stop thinking about biological security in the way we think about nuclear security. Few aspects of the United States strategy for nuclear security carry over cleanly to the biological case. Security against nuclear attack has relied upon nonproliferation and deterrence, with comparatively little role, so far, for defense. Security against biological-weapons threats should lean primarily on defense.

Nonproliferation, for example, is far more difficult in the biological case. Biological agents are microscopic organisms that can be grown with equipment readily available all over the world -- although the resulting weapons have proved difficult for terrorists to master. Many of the organisms can be acquired during naturally occurring outbreaks. Controls remain valuable, but they will never play the central role that they do in nuclear security. And as biotechnology explodes in the coming decades, nonproliferation will face ever greater challenges.

Deterrence may likewise be of limited use in preventing attacks with biological weapons. While the use of battlefield biological weapons may be deterred by threats, biological terrorism could remain largely immune. The incubation times of most diseases -- for example, seven to 17 days for smallpox -- may lead terrorists to hope they can cover their tracks through covert releases of biological agents. Deterrence relies on the threat of punishment. An attacker who cannot be identified cannot be threatened.

When the Aum Shinrikyo cultists sprayed an anthrax organism in Tokyo -- they did so unsuccessfully several times before their deadly 1995 nerve-gas attack -- they made no announcements and the attacks went unnoticed. When followers of the Bhagwan Shree Rajneesh infected 750 Oregonians in 1984 with salmonella, it took over a year for the attack to be distinguished from a natural outbreak.

Rather than nonproliferation and deterrence, biological security must emphasize civil defense. Civil defense in the biological realm means improving the public health system. Most important, it requires improving disease surveillance. Unusual disease outbreaks must be recognized quickly, so that a rapid response is possible. Health care workers in clinics, hospitals and private practice must know how to identify such outbreaks and be ready and able to pass their information rapidly to city, state and national authorities.

This kind of preparedness would also help to prevent unintentional outbreaks of disease. Because infected passengers can travel the world in less time than it takes for a disease to incubate, it is crucial, for the national interest as well as for humanitarian reasons, to improve disease surveillance overseas. The United States welcomes 50 million visitors every year and imports $40 billion worth of food. Disease cannot be stopped at the border. The United States must act internationally as well as nationally.

Because biological security would offer protection against both natural and nefarious transmission of disease, a sound policy would directly benefit society even if no attack ever happened. Effective biological security requires that we fit the cure to the disease.

The official U.S. government policy is to maintain "calculated ambiguity" about whether the United States would retaliate with nuclear weapons in response to an adversary's use of chemical weapons (CW) or biological weapons (BW) against U.S. allies, U.S. armed forces overseas, or the U.S. homeland. Since the 1991 Gulf War, numerous civilian and military leaders have stated that the United States might use nuclear weapons in response to CW and BW threats or attacks, and some have even stated that the United States will use nuclear weapons in such circumstances. The central argument in my spring 2000 International Security article was that this policy has created a dangerous "commitment trap" problem.

The benefit of making such nuclear threats, whether stated ambiguously or clearly, is that they can increase an adversary's estimate of the probability that the U.S. president would order nuclear retaliation, which should therefore decrease the likelihood of chemical or biological weapons attacks. But there is a serious cost attached to this obvious benefit: If deterrence fails despite nuclear threats, the statements will also increase the likelihood that the United States will actually use nuclear weapons, because the president's personal and the U.S. government's institutional reputations for following through on threats would be perceived to be at stake.

I argued that current U.S. nuclear doctrine has therefore created a subtle dilemma that has not been recognized, much less debated, in both policy and academic circles: Is the improvement in the U.S. ability to deter CW and BW threats worth the increased likelihood of a U.S. nuclear response if deterrence fails?

A biological terrorist attack probably would first be detected by doctors or other health-care workers. The speed of a response would then depend on their rapid recognition and communication that certain illnesses appeared out of the ordinary. For this reason, preparing for biological terrorism has more in common with confronting the threat of emerging infectious diseases than with preparing for chemical or nuclear attacks. Defense against bioterrorism, like protection against emerging diseases, must therefore rely on improved national and international public-health surveillance. Too often, thinking about bioterrorism has mimicked thinking about chemical terrorism, a confusion that leads to an emphasis on the wrong approaches in preparing to meet the threat.

This paper focuses on the question of how much protection a building provides its inhabitants from a BW attack. The reason for considering this problem is simple: most people spend the majority of their daily lives inside buildings. In fact, the U.S. EPA estimates that average Americans spend approximately 87% of their time indoors.5 However, most previous technical assessments of BW incidents ignore the effects of buildings, computing casualties based only on integrated outdoor surface dosage. The protective effects of buildings have been considered for other toxic releases. Karlsson, for example, looks at the effects of indoor deposition upon toxic gas clouds,6 and Engelmann7 and others examine the sheltering effectiveness of buildings against respirable plutonium releases. In this paper we seek to extend these basic ideas to biological agents and to explore aspects of the problem that are unique to biological weapons.

The rest of this paper is organized as follows: A brief discussion of general aspects of biological weapons is first presented. Then, we introduce the method used to model the penetration of buildings by biological agents and discuss the factors that determine the sheltering effectiveness of a particular building. The paper concludes with a discussion of simple measures that individuals can enact to increase the sheltering effectiveness of a particular building.

The proliferation of chemical, biological, and nuclear weapons is now the single most serious security concern for governments around the world. Peter R. Lavoy, Scott D. Sagan, and James J. Wirtz compare how military threats, strategic cultures, and organizations shape the way leaders intend to employ these armaments. They reveal the many frightening ways that emerging military powers and terrorist groups are planning the unthinkable by preparing to use chemical, biological, or nuclear weapons in future conflicts.

Distinguished specialists consider several states and organizations that have this weaponry: Iraq, Iran, India, Pakistan, North Korea, and Israel, as well as the Aum Shinrikyo cult. The contributors expose plans for using unconventional weapons, highlighting the revolutionary effects these arsenals might have on international politics and regional disputes.

It is no exaggeration to say that arms control has undergone a revolution in the past decade. In the forty years since the bombings of Hiroshima and Nagasaki ended World War II and began the nuclear age, governments, organizations, and individuals have worked to reduce the threat of wars between great powers employing weapons of mass destruction-nuclear, chemical, and biological. Some progress was made during this period; the Limited Test Ban Treaty (LTBT) of 1963, the nuclear Non-Proliferation Treaty (NPT) of 1970, and the Anti-Ballistic Missile (ABM) Treaty and Biological Weapons Convention (BWC) of 1972 were the more notable achievements. But progress was always slow, frustrating, and tentative, with no assurance that the whole fabric might not be undone by an increase in superpower tension or by domestic forces in either the United States or USSR hostile to the very concept of arms control.

This article will consider whether the principles of the Geneva Protocol have become so widely accepted that they apply to the United States even though it is not a party. It will analyze the effect of existing reservations to the Protocol, discuss the United States use of tear gases and herbicides in Vietnam in light of its provisions, and recommend that the Protocol be approved by the Senate. This article will first describe the international agreements dealing with poison gas and germ warfare, and the reasons which prevented the United States from becoming a party to them.