You burst into the room. Sitting on a chair, blindfolded, his hands tied behind his back, is your prisoner. The room is dark, except for a lonely naked bulb hanging from the ceiling. He is sweating. He is afraid.

"Tell me where it is!" you scream. "Now!" You know there is little time left. Somewhere in your city, a time bomb is ticking. Whether it spits serin into the air, uranium into the water or atomic fire into the heavens, you do not know.

He does. But he is not talking. Involuntarily, you raise your hand as if to strike. What you are about to do violates the law and your conscience. And yet. ...

In peacetime, torture ranks next to murder as a primal sin. But during war, the debate begins over whether this evil can ever be justified to combat the seemingly greater evil of the enemy. Harvard law Professor Alan Dershowitz has said torture should be legalized.

In early October, the U.S. Senate voted 90-9 to ban it. Although Secretary of State Condoleezza Rice and President Bush have both recently asserted that "We do not torture," five U.S. Army Rangers were charged in November for punching and kicking detainees in Iraq, secret U.S. prisons have caused anxiety in Europe, and Vice President Dick Cheney has battled to win the CIA an exemption from the torture ban. As late as December, the U.S. House of Representatives stood poised to defeat the White House.

Few of us will ever be asked to torture. But, indirectly, all of us have to make a choice: to support, as citizens, those politicians who back torture, or those who seek its prohibition.

The decision of an individual to support, or reject, torture seems at first to be a purely moral question. But what would be the long-term consequences to society if we were to make this radical break with the past?

One cannot do experiments with societies, or predict the future, but, it turns out, one can attempt to address this issue using the cold, hard tools of mathematics and logic. This story begins in 1963.

The United States and the Soviet Union are on the perpetual brink of war, balanced like two sides of an equation. On the American side are "game theorists" like Thomas Schelling, recently awarded the Nobel Prize for his work on the strategy of conflict. On the Soviet side, there is the solitary mathematical psychologist Vladimir Lefebvre.

Just as mathematics could be used to describe logical reasoning, Lefebvre saw that mathematics could be used to describe ethical reasoning. If something was good -- for example, "church," "democracy," "prosperity," "kindness" -- it had value "1."

If something was evil -- "earthquake," "famine," "military defeat," "murder" -- it had value "0." But rarely were ethical situations so simple. For instance, "killing" is bad (0) but protecting one's country is good (1) -- so is war 1 or 0?

Lefebvre saw that, at the crudest level, there were essentially two types of ethical systems. Those that held that employing evil means to attain just ends was good, and those that saw that employing evil means to attain good ends was wrong.

There were also, crudely put, two types of relations between individuals: those entailing compromise (or cooperation) and those entailing confrontation.

Of course, evil people rarely see themselves as evil. So Lefebvre had to incorporate in his model of human nature the capacity of human beings to judge -- correctly or incorrectly -- the goodness or evil of their own acts, and to reflect upon their own judgments, and others'. "Reflexive Theory" was born.

It quickly became a paradigm within the Soviet defense establishment, with the publication of books such as "Mathematics and Armed Conflict." Nothing like it was known in the West.

With very simple assumptions -- for instance, that an individual who correctly sees his actions to be good when they are good, and evil if they are evil, is more highly regarded by society than an individual who incorrectly sees himself -- Lefebvre showed that in a society that accepted the compromise of good with evil, individuals would more often seek the path of confrontation with each other.

Lefebvre's insights were called upon by the State Department during negotiations with Mikhail Gorbachev in Reykjavik, Iceland. (And perhaps Lefebvre's model could be re-enlisted to help U.S. officials understand and negotiate with Arab and Muslim heads of state, who must also negotiate with their people.)

In support of Lefebvre's revolutionary new theory, a survey of Soviet émigrés and Americans was conducted in the 1970s. They were asked questions like, "Should a doctor conceal from a patient that he has cancer in order to diminish his suffering?" Overwhelmingly, the Americans would say no, and overwhelmingly, the Soviets yes. The Soviets accepted the compromise of good with evil; the Americans rejected it.

What does this mean? If Americans begin to accept the use of torture, American society might turn into a society of individuals in conflict.

Not uniformly, thanks to something called free will, but generally, with harmful consequences for society: Imagine two roads, with a stream of cars moving along each one. Each driver wants to reach his destination as quickly as possible; on occasion, drivers will impede each other.

On the first road, drivers rise in their own, and in other drivers', estimation if they yield. Drivers on the second road lose face when they yield. It is clear that traffic will move faster on the first road than on the second.

It can be argued that repressive states like Saudi Arabia, which bred most of the Sept. 11 hijackers, are on the second road. If the United States moved to accept torture, it could veer toward the second road, too -- the road of the Soviet Union.

And we know where that road ends. The Soviet Union no longer exists.

Chapter 6 in Reappraising Openheimer: Centennial Studies and Reflections, edited by Cathryn Carson and David A. Hollinger (Office for History and Science of Technology, University of California, Berkeley, 2005).

The editors write: "From the beginning all the way up to the present, the Soviet nuclear weapons project has served as foil for the American effort. It preoccupied Robert Oppenheimer's minders in the Manhattan Project, fixated by the possibility of espionage; it drove his postwar attempts to achieve international control of atomic weapons just as surely as it lit up his opponents' mistrust of his stance on the hydrogen bomb. Throughout the arms race, Soviet progress vis-a-vis American weapons production helped drive the dynamic of the Cold War. More recently, Soviet and post-Soviet sources have inspired careful reanalysis of the dual courses of the two nations' nuclear projects. That effort has shed new light on the conditions under which Oppenheimer's wartime labors could find the conclusion they did. . . .

"David Holloway explores parallels between Robert Oppenheimer and his Soviet counterpart, Iulii Khariton. Similarities in background and differences in role make Holloway's contrast instructive."

Paul Collier and Anke Hoeffler at Oxford University have reported that countries with a higher percentage of national income from primary commodity exports have been more prone to civil war, an interesting finding that has received much attention from policy makers and the media. In this paper, James Fearon shows that this result is quite fragile, even using Collier and Hoeffler's data. Minor changes in the sample framing and the recovery of missing data undermine it. To the extent that there is an association, it is likely because oil is a major component of primary commodity exports and substantial oil production does associate with civil war risk. Fearon argues that oil predicts civil war risk not because it provides an easy source of rebel start-up finance but probably because oil producers have relatively low state capabilities given their level of per capita income and because oil makes state or regional control a tempting "prize." An analysis of data on government observance of contracts and investor-perceived expropriation risk is consistent with this hypothesis.

A net assessment of the benefits/losses of arms control treaties in terms of military significance was required in response to the START Resolution of Ratification. The response by the Executive Branch belabored smaller issues, avoided accomplishments and didn't carry out the net assessment.

We investigate the impact on effective terrorism response of the viability degradation of biological weapons agents in the environment. We briefly review the scientific understanding and modeling of agent environmental viability degradation. In general, agent susceptibility to viability loss is greatest for vegetative bacteria, intermediate for viruses, and least for bacterial spores. Survival is greatest in soil and progressively decreases in the following environments: textiles, water, hard surfaces, and air. There is little detailed understanding of loss mechanisms. We analyze the time behavior and sensitivity of four mathematical models that are used to represent environmental viability degradation (the exponential, probability, and first- and second-order catastrophic decay models). The models behave similarly at short times (<30 min for our example case) but diverge to significantly different values at intermediate to long times. Hence, for a release event in which the majority of atmospheric exposure or deposition occurs over very short times, the current response models likely provide a good representation of the hazard. For longer time phenomena, including decontamina tion, the current model capabilities are likely insufficient. Finally, we implement each model in a simple numerical integration of anthrax dispersion, viability degradation, and dose response. Decay models spanning the current knowledge of airborne degradation result in vastly different predicted hazard areas. This confounds attempts to determine necessary medical and decontamination measures. Hence, the current level of understanding and representation of environmental viability degradation in response models is inadequate to inform appropriate emergency response measures.

On June 16, 2002, Dennis Pluchinsky, a senior intelligence analyst at the U.S. Department of State, wrote an article in the Washington Post calling for censorship. The article began, "I accuse the media in the United States of treason." Pluchinsky, who worked counterterrorism in the government for twenty-five years, pointed to post-9/11 articles that revealed not scientific advancements, but American vulnerabilities in regard to the food supply, electricity, chemical production, transportation, and border security. He suggested that research conducted by the media could not have been funded by one, single terrorist organization: "Our news media, and certain think tankers and academicians, have done and continue to do the target vulnerability research for them."

Pluchinsky has a point. Terrorist organizations can and do use the media--and the protections afforded speech in the United States and the United Kingdom--to obtain and disseminate critical information.

The crucial point is this: Both liberal, democratic states, and nonstate terrorist organizations need free speech. Under what circumstances are the interests of the state secured and the opportunism of terrorist organizations avoided? Here, the experiences of the United States and United Kingdom prove instructive. On both sides of the Atlantic, where the state acts as sovereign, efforts to restrict persuasive political speech have relaxed over time to allow for more criticism. In the United States, Brandenburg v. Ohio cemented this shift. In the United Kingdom, change came gradually. The practical elimination of treason and seditious libel, and incorporation of the European Convention of Human Rights (ECHR) into domestic law through the 1998 Human Rights Act (HRA), marked the transition. If free speech remains central to our understanding of liberal democracy, it would nevertheless be naïve to rely on these alterations to protect expression in the contemporary counterterrorist environment--regardless of how remarkable they might be in the context of what went before.

Underlying my argument in this paper is a deeper concern that centers on the shifting nature of technology. What the average person could have done in 1776, or for that matter, 1976, to hurt either state pales in comparison to what a person with basic knowledge of microbiology, $1000, and a lab can do today. But neither American nor British law appears to have come to terms with what weapons of mass destruction, in terrorist hands, means for free speech.

This article won the 2004-2005 Steven M. Block Civil Liberties award for the best piece of writing in civil liberties at Stanford Law School. It also won second place in the national competition for the 2005 Judge John R. Brown Award for Excellence in Legal Writing, which recognizes the best legal writing by U.S. law students.