It's been said that World War I was the chemists' war and World War II the physicists' war, but that World War III is destined to be the mathematicians' war.

With the gravest threat to U.S. security now posed by rogue terrorists who simultaneously hold a grudge and have access to weapons of mass destruction, some of this country's prime human calculators are on the case.

Combatting terrorism not with mortars and missiles but with mathematical models, they intend to prove this theorem: There literally is safety in numbers.

In their vanguard is an amiable Stanford University professor who, by devoting himself to the application of math principles to doomsday scenarios, is beginning to acquire the nickname "Dr. Doom." The attacks of Sept. 11 inspired mathematician Lawrence Wein to channel his expertise into some of the most compelling questions of our time.

He has ciphered the risks of our "woefully inadequate" inspection of container ships, assessed the effectiveness of border-control fingerprint checks to spot terrorists, and performed what may well be the first math analyses of hypothetical botulism, anthrax and smallpox contaminations.

Recall the agitation last year over warnings that the nation's milk supply was vulnerable, based on the calculation that one terrorist with a few grams of botulinum could contaminate a tanker and potentially poison 100,000 gallons of milk? That's just one of many tidings of comfort and joy brought to you by Wein.

Another such upper is that just about 6 percent of containers shipped into U.S. ports will be categorized as suspicious and subjected to tests for a nuclear device, based on a system that relies largely on reporting by the shipper. The rest, Wein noted, "just waltz right into the country without an inspector laying an eye on them."

At Stanford's Graduate School of Business, he teaches a core course in operations, and he says the parallels are strikingly similar: Just as McDonald's needs a well-designed distribution system to get its hamburgers out quickly, so the government needs a well-designed distribution system to get vaccines and antibiotics to citizens who might sicken or die from a bioterror attack. In math lingo, some of these computations rest on "queueing theory" -- the notion that a lot of needy people must line up behind a limited number of distributors.

And what do we do after crunching millions of numbers to arrive at specific prescriptions? Wein has taken on the role of necessary nag to a torpid federal bureaucracy and recalcitrant industries.

In fact, the feds scrambled to try to suppress publication of his damning milk study as a threat to national security -- an argument the journal Proceedings of the National Academy of Sciences rejected before publishing the work.

These days, Wein regularly testifies at congressional hearings, addresses scientific forums and pens op-ed pieces in national newspapers about precisely what the government should be doing -- and where it is falling short.

"I believe my work demonstrates that numbers really matter, and we need to pay attention to what they tell us," said Wein, a critic of the federal government's homeland security failures in key areas, particularly at the ports. "I really don't bring my own personal political views into this -- I would be just as critical of the federal bureaucracy if a Democrat were in the White House.

"Bureaucracy just isn't designed to respond nimbly."

On the other hand, politicians are eager to do something, anything, that might thwart a terror attack or save lives. But in an information vacuum, that makes them easy prey for entrepreneurs hawking all kinds of safety gadgets.

So, much of Wein's math analysis goes beyond documenting threats to assess the most effective, cost-efficient remedies.

Take the milk scare, for example. Wein urged the government to mandate that milk tanks and trucks be locked, that two people be present when it is transferred along each part of the supply chain, and that milk truck drivers use a 15 minute test to detect any toxins. The estimated cost of all this: 2 cents per gallon.

Some other experts disputed Wein's assumptions, and dairy industry groups insisted they already had taken extra steps such as raising pasteurization temperatures to secure the milk supply. They dismissed the scenarios Wein described as "highly unlikely or impossible."

To avoid being victimized by a radioactive device aboard a tanker -- otherwise known as a "poor man's missile" -- he and colleague Stephen Flynn of the Council on Foreign Relations advocate using techniques such as gamma-ray imaging to screen 100 percent of containers. They calculate the cost at $7 per container.

Some of Wein's calculations have translated into real reform.

In 2004, he presented to the White House his findings that the system of collecting only two fingerprints from incoming foreign visitors ran a high risk of missing terrorists because so many prints turned out to be of poor quality. His solution was simple: Take prints from all 10 digits. The government adopted it.

His 2003 research into the most effective response to an anthrax attack prompted pilot programs that are now testing his finding that the best way to widely distribute antibiotics would be by mail carriers, who already go door to door.

Albert Einstein once observed: "As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality."

And sure enough, one of the impediments to fighting terrorists with mathematics is the paucity of hard data.

An anthrax scenario illustrates the point. Estimates of fatalities per kilogram of poisonous agent released vary from a low of zero to a high of 660,000. That's because of variables: the dose required to cause infection, the percentage of people who survive infection, the degree of aerosol dispersion, the density of the population, the environmental stability of the agent and the effectiveness of a public health system response.

As Wein acknowledges, "It's not like we can do massive clinical trials on this."

The trail of what-ifs is so convoluted that in 2002 the National Academy of Sciences cited "an irreducible uncertainly of several orders of magnitude in the number of people who will be infected in an open-air release."

This makes some experts suspicious of anybody's calculations, even from a researcher with a pedigree like Wein's.

"With so much uncertainly surrounding the outcome of a bioweapons attack, it does not make sense to plan extensive biodefense programs when more-certain public threats, particularly those involving nuclear weapons, require attention," argued Allison Macfarlane, research associate in the Science, Technology and Global Security Working Group at MIT.

But Wein is undeterred, and is busy on new assessments. Yet he insists his work has not impaired his ability to sleep soundly.

"People really are much more likely to suffer from cancer than a terrorist attack, but that doesn't merit the same attention," he said. "We should do what makes sense to protect ourselves from both."

One day perhaps Marina Agaltsova will join the diplomatic corps at a foreign embassy, or help write policy positions for the Russian government. Coit Blacker hopes that the lessons from her Stanford-sponsored distance-learning course will stick.

Agaltsova was among a group of Russian students brought to the provincial city of Yaroslavl in late May for an academic conference that capped this year's five distance-learning courses offered at nine universities across Russia by the Initiative on Distance Learning at the Freeman Spogli Institute for International Studies.

Through videotaped lectures, web readings and online chat sessions with senior research scholar Kathryn Stoner-Weiss and 14 other Stanford instructors, students in Democracy, Development and Rule of Law explored democratic ideals and practices, studying examples in Latin America, Asia and the former Soviet Union. "The course taught me that there is a black side to the reforms" that followed perestroika in Russia, Agaltsova says. "I learned more about Russian history [in the course] than I had learned in school."

That's the idea, says FSI director Blacker, who wants to re-establish the teaching of critical analysis, lost under decades of Communist rule, in Russian universities. "The social sciences were disemboweled," he says. He wants to develop future generations of diplomats and policy makers whose worldview is shaped "by how they think, not what they're told to think."

This year, to cap off the courses, 40 students came to Yaroslavl to participate in a mock United Nations Security Council session addressing Iran's nuclear program. They traveled from the farthest reaches of the Russian hinterlands, like Amur State University in Blagoveschensk, 4,800 miles from Moscow.

The arms control simulation is a teaching tool developed for the Stanford undergraduate class International Security in a Changing World, taught by Blacker and Scott Sagan, a political science professor and director of the Center for International Security and Cooperation within FSI. Sagan has exported the simulation to several universities in the United States where his former graduate students now teach--UC-Berkeley, Dartmouth, Columbia, Duke--but this was the first one he has conducted overseas.

This year's scenario was the International Atomic Energy Agency's referral of Iran to the U.N. Security Council for failure to fully disclose its nuclear activities. During the simulation, students submitted proposals to their heads of state, played by Blacker, Sagan and Russian faculty members. By the end of the two-day session, delegates had overcome seemingly intractable differences during four intensive sessions led by Stanford third-year law student Matthew Rojansky, acting as U.N. undersecretary-general for legal affairs. The council's resolution gave Iran three months to comply with the IAEA's requests and provided for Iran to obtain nuclear fuel from Russia, with the production and waste disposal to occur on Russian soil under IAEA controls.

After the session closed, students set aside their delegate roles to reflect on what they had learned. Narina Tadevosian, a student from Yakutsk State in far eastern Siberia, said she was surprised at "how strict Russia was" in taking a leading role in the session.

"If only it were so in real life," she added.

Americans have never been in greater need of understanding religious differences and cultivating respect for religious freedom. The events of 9/11 transformed America's relationship with Muslims at home and abroad, a surge in immigration from Asia and Africa has increased the nation's religious diversity, and cultural conflicts between secularists and religious conservatives occur like clockwork.

So you might think the last thing school districts would want is to bring religion into the classroom. Better to play it safe, and avoid lawsuits and angry parents by limiting any mention of faith to the private sphere. But school officials in Modesto, in Northern California, decided not to play it safe. In 2000, the religiously diverse community took a risk and, in an almost unheard-of undertaking for a public school district, offered a required course on world religions and religious liberty for ninth-graders.

As college professors and social scientists studying religious freedom in the USA, we wanted to know more. Could greater discussion of religious differences actually deepen cultural divides? From October 2003 to January '05, we surveyed more than 400 Modesto students and conducted in-depth interviews with students, teachers, administrators and community leaders. We granted anonymity to students so they could speak freely, but we recorded the interviews. No prior study on American teens' views on religious liberty has scientifically surveyed such a large number of students.

To our surprise, students' respect for rights and liberties increased measurably after taking the course. Perhaps more important, the community has embraced the course as a vehicle for fostering understanding, not indoctrination.

All-American city

Modesto, population 190,000, resembles many medium-size U.S. cities. Over the past 40 years, it has made room for an array of immigrants, including Buddhists, Sikhs and Muslims. Evangelical "megachurches" have sprung up alongside mainline Protestant and Roman Catholic denominations and a flourishing Jewish community. Overt incidents of religious prejudice have been rare, but the cultural divide bred mutual suspicion.

In 1997, some religious groups in Modesto battled the school over a policy of tolerance for gay and lesbian students. Out of the dispute came a meeting of the minds: A 115-member committee of community members and educators was formed to examine how to provide safe schools for all students. That meant putting an end to bullying, whether based on sexual orientation, race or ethnicity--even religion. The world religions course was one of several initiatives designed to further the "safe schools" mission.

The experiment succeeded. Our surveys indicate it increased students' respect for religious liberty as well as for basic First Amendment rights. One Russian Orthodox boy, for instance, found that the course brought him closer to his neighbors. "We have a Hindu family living across the street who pray(s) to a statue," he said. "I thought it was just plain dumb. But I notice now they had a pretty good reason."

Bringing religious beliefs out into the open increased students' respect for religious liberty for two reasons. First, students not only emerged from the course far more knowledgeable about world religions, they also were able to apply the knowledge practically. One student told us that the course gave him a greater appreciation for the religious diversity in his school. "I walk up to one of my friends I've known for years. I had no idea he was a Sikh. When I see the bracelet (worn for religious reasons), I say, 'Oh, you're a Sikh.' "

Second, students learned that major faiths shared common moral values. When we asked one student why she enjoyed studying other religions, she said: "All my life I've been a Christian, and that's really the only religion I know about. So when I take this class I see there are other religions out there, and they kind of believe in the same thing I do."

Even so, students did not become relativists or converts. They were no more likely to disbelieve the truth of their own religious traditions after taking the course.

A broad spectrum of Modesto's residents has embraced the course. Students can opt out, but only a handful have. The school board, which stands divided on other hot-button cultural issues, voted unanimously to adopt the course. Religious leaders of all faiths lent their support because they realized that something had to be done to bring peace to the schools--and that pushing religious identity undercover would create more problems than it solved.

Lessons beyond Modesto

Recent disputes over the teaching of evolution in Kansas and Dover, Pa., and over a Bible studies course in Odessa, Texas, have made national headlines. These stories leave the impression that all attempts to teach about religion in public schools--even courses far more balanced than these disputed courses--are bound to cause controversy. How did Modesto avoid this fate, and what lessons does Modesto provide for other communities?

• Extensive training gave teachers the knowledge and enthusiasm to handle a sensitive subject.
• An interfaith religious council reviewed the course before its implementation and paved the way for its acceptance. The council members applauded particularly the district's decision to have the course focus on objectively describing religions rather than evaluating their merits.
• The focus on description prevented the perception that the course was biased or an attempt to indoctrinate students into a particular faith.
• Most crucial was the school district's decision to introduce the course as part of an effort to counteract the hostility against students who were seen as different.

Limiting deeply held beliefs to the private sphere breeds suspicion and tension. True religious liberty prevails not only when people feel comfortable expressing their beliefs, but also when they learn to discuss religious differences with civility and respect.

 Emile Lester is an assistant professor at The College of William and Mary. Patrick S. Roberts is a postdoctoral fellow at the Center for International Security and Cooperation at Stanford University.

North Korea is poised to flight test a ballistic missile that may have intercontinental range -- an action the Bush administration declares would be provocative. Others have called for sanctions if the flight test occurs, the use of U.S. ballistic-missile defenses to intercept the missile in flight or a pre-emptive attack against the missile-launch site. But is this missile test a red line that, if crossed, seriously threatens U.S. security and, hence, warrants strong action? The simple answer is "No."

In thinking about this test, one must not lose sight of two paramount goals: rolling back North Korea's nuclear weapons program and the eventual peaceful reunification of North and South Korea. Ballistic missiles constitute a serious threat to the U.S. homeland only when armed with nuclear warheads and they are only one delivery means for such weapons. In this sense, ballistic missiles are of secondary concern. By most estimates, North Korea has sufficient nuclear material for a few nuclear explosive devices, but whether they can design a nuclear weapon that satisfies the size, weight and delivery constraints associated with intercontinental-range ballistic missiles is far from obvious.

If North Korea tests a three-stage version of the Taepodong-2 missile, it will likely attempt to put a satellite into orbit, just as it did in 1998 when it failed to place a satellite into orbit with the smaller Taepodong-1 missile. North Korea has a sovereign right to launch satellites, or to test ballistic missiles for that matter. International protocol requires launch notification and restrictions on air and marine traffic for reasons of range safety -- steps North Korea failed to take in 1998 -- but no international agreement bars this test. True, North Korea agreed to a unilateral moratorium on ballistic missile flight tests in 1999, pending further talks with the United States regarding North Korea's missile program, but the Bush administration refused to join these talks. North Korea leader Kim Jong Il reaffirmed this flight test moratorium in the 2002 Pyongyang Declaration signed with Japan, but this document is not a legally binding commitment.

If successful, this flight test would demonstrate that North Korea can produce rockets large enough to carry payloads intercontinental distances. However, this does not translate into an immediate threat because North Korea has not demonstrated that it can build a nuclear warhead that is small enough to fit on top of a Taepodong-2 missile and that can survive re-entry into the atmosphere after flying intercontinental distances.

Given vastly superior U.S. conventional and nuclear forces, deterrence should dissuade North Korea from ever using such missiles, except for saber rattling, or worse selling nuclear weapons or nuclear material abroad (this is a serious red line). Kim Jong Il may be a ruthless totalitarian leader, with little regard for the welfare of his people, but he is not suicidal.

More important, these missiles would be highly vulnerable to pre-emptive attack in the midst of a crisis, which is when pre-emption makes sense, because these missiles are large and easy to detect, they are not mobile, and they take many hours, if not days, to erect in a vertical position and fuel -- precisely the activity that generated this concern.

On the other hand, U.S. sanctions against North Korea in the wake of a test flight could backfire. They would likely cause rifts with other friendly parties to the Six Party talks aimed at eliminating North Korea's nuclear weapons, especially China. U.S. national missile defenses may not be within range, depending on the flight trajectory, to intercept this flight test. If this unproven U.S. missile defense were to fail and North Korea's flight test succeed, the Bush administration would be embarrassed, and Kim Jong Il triumphant. And, pre-emptive attack against the test facility would be a unilateral act of war at a time when U.S. unilateralism has hurt more than helped U.S. vital interests. South Korea would adamantly oppose such adventurism because Seoul is vulnerable to retribution, being within artillery range of the Demilitarized Zone.

So, what should the United States do on the eve of this flight test? Nothing, beyond expressing its dismay that North Korea appears to favor conflict over cooperation.

A Taepodong-2 flight test allows the United States to learn more about this missile than North Korea, given the concentration of technical intelligence assets in the area, which would help resolve the question of whether this missile, in fact, constitutes a serious threat to the U.S. homeland. In addition, such a test would isolate North Korea further and reinvigorate the Six Party Talks by encouraging South Korea, China, Japan, Russia and the United States to overcome their differences and create a united front to persuade North Korea to renounce its nuclear weapon program, which is the real threat.

Stepping back, U.S. leaders should see that North Korea is a mouse and the United States the elephant. Contrary to popular mythology, elephants are not, and should not be, afraid of mice.