Timely reunion panel hosted by Stanford president John Hennessy, moderated by Stanford alum Ted Koppel, and featuring Bill Perry and George Shultz.

The final decade of the 20th century was a time of great optimism. The fall of the Iron Curtain ushered in a new era of democracy and freedom for millions. The expansion of the European Union promised to open borders to trade and opportunity. The technology revolutions of the 1990s promised to bridge cultural gaps and unite diverse people.

Yet, in the first decade of the 21st century, this optimism has faded in the face of myriad threats: the menace of terrorism and nuclear proliferation, the danger of virulent pandemics, the global dependence on oil from volatile regions, and the far-reaching and often unsettling implications of an interconnected planet.

In such uneasy times, is it safe to feel safe? What is the way forward in the midst of these challenges? What will it take? What is Stanford doing to help address these issues?

Panelists

John L. Hennessy, Stanford President and Bing Presidential Professor

Jean-Pierre Garnier, MBA '74, CEO, GlaxoSmithKline

The Hon. Anthony M. Kennedy, '58, Supreme Court Justice

William J. Perry, '49, MS '50, former Secretary of Defense, Berberian Professor in the School of Engineering

Dr. Lucy Shapiro, Ludwig Professor of developmental biology and cancer researcher

George P. Shultz, former Secretary of State, Ford Distinguished Fellow, Hoover Institution

Jerry Yang, '90, MS '90, co-founder, Yahoo!

Given Tehran's defiant response to the European and American effort to constrain its nuclear program, it is time for bolder diplomacy out of Washington. U.S. President George W. Bush should take a page from the playbook of Ronald Reagan, who negotiated with an evil Soviet regime--competing in the war of ideas, but addressing the enemy's security concerns through arms-control agreements.

Iran's intransigence is both deeply unfortunate and perfectly predictable. It is unfortunate because Tehran's refusal to suspend its uranium-enrichment operations immediately--as demanded in July by the U.N. Security Council in a legally binding resolution--suggests that Iran is moving more quickly than expected toward a nuclear-weapons capability. Tehran has now turned the nuclear crisis into a test of the whole U.N. Security Council system. And Russia and China's current position, threatening to veto any biting sanctions against Iran, suggests that the Security Council may well fail this crucial test.

Tehran's response is predictable, however, because the offer on the table contains both inadequate economic carrots and barely credible threats of sanctions and military force. The carrots appeared impressive at first glance--in return for a suspension of enrichment we reportedly promised to provide light-water nuclear reactors and to help Iran with civil aviation and telecommunications technology. But we did not offer the one incentive that might possibly work, security guarantees that could reduce Iran's desire for nuclear weapons.

This omission is striking. The Iranian government can't talk openly about their security concerns because that would blow their cover story that the nuclear program is only for energy production. And Washington does not want to discuss such worries because it wants to keep open the possibility of removing the regime by force. "Security assurances are not on the table," U.S. Secretary of State Condoleezza Rice too cleverly argued this spring: "It is a little strange to talk about security guarantees ... I thought the Iranian position was that they weren't developing a nuclear bomb."

This is partly a crisis of our own making, as the Bush administration has practiced the reverse of Teddy Roosevelt's maxim--speaking loudly and carrying a small stick. Think about how Tehran reacted when Bush stated (in his second Inaugural Address), "The rulers of outlaw regimes can know that we still believe as Abraham Lincoln did: 'Those who deny freedoms to others deserve it not for themselves; and, under the rule of a just God, cannot long retain it." Or when Bush dramatically told reporters last April that "all options are on the table," in direct response to a question about whether he was considering a nuclear attack against Iran. Such statements only encourage Iran to develop a nuclear deterrent quickly, before the United States can carry out its perceived aggressive intent. Last month, Iran's National Security Council Secretary Ali Larijani pointedly complained about such rhetoric. "How can a side that wants to topple the regime also attempt to negotiate?"

Given the current vulnerability of U.S. forces in Iraq, the deteriorating situation in Afghanistan, and the lack of Israeli success against Hizbullah, Iranian officials seem confident that they face no immediate threat of a U.S. military assault. But they are clearly worried that Bush just might attack Iran right before he leaves office in January 2009, or that his successor might do so once U.S. forces withdraw from Iraq.

The best way to prevent a nuclear Iran is for Washington to offer the kind of security assurances that might reduce support in Tehran for building a nuclear arsenal. It will be hard to make such assurances credible, but a public U.S. promise to take forcible regime change off the table, and a U.N. Security Council commitment to protect the "political sovereignty" of Iran could help. Involving the Security Council could also pull China and Russia back into the nonproliferation coalition and enhance the U.N.'s legitimacy.

There is very little time left, which means negotiations should begin despite Iran's unfortunate opening position. Tehran's response reportedly indicated a willingness to negotiate all aspects of its nuclear program, so working out an agreement for Iran to limit itself to low-level uranium enrichment might still be possible. This would work only if Tehran accepts full IAEA inspections and a freeze on future centrifuge construction. Will they? The one thing that might cause Tehran to do so, and that would compensate for any loss of face, would be an assurance that the United States will not launch another preventive war, as it did in Iraq, to remove the Iranian regime. If in turn we get a nuclear-free Iran, that's a good deal for the West as well.

As a model of a democratizing and secular Muslim state that has been a stalwart ally for more than 50 years, Turkey is of enormous strategic importance to the United States and Europe, especially at a time when the widening chasm between the West and the Islamic world looms as the greatest foreign policy challenge. Yet Ankara's relations with Washington are strained - over Iraq, Cyprus, Syria, Iran and Hamas - and Turkey's prospects for joining the European Union remain uncertain.

As Washington prepares for a visit Wednesday by Turkey's foreign minister, Abdullah Gul, the United States and Turkey should explore three initiatives to repair and revitalize their relationship.

First, although the United States and Turkey share broad goals in Iraq, the situation there threatens a potential breach in relations. The Turks feel the war in Iraq has undermined their security by stirring Kurdish nationalism. It also coincided with renewed terrorist attacks mounted by the Kurdistan Worker's Party from inside Iraq. To address this challenge, the United States should initiate a trilateral dialogue on the future of Iraq with Turkey and representatives of the Iraqi government, including Kurdish leaders.

If the effort to build a functioning Iraqi government is successful, this trilateral consultative process will support the common goal of a unified and sovereign Iraq; should the Iraqi government fail, the dialogue will provide a mechanism for managing some of the worst potential consequences.

Second, Washington must make it a diplomatic priority to persuade skeptics in Europe to take a more positive approach toward Turkey. Peering into the future and considering the strategic implications of a Turkey unmoored - or, more darkly, a Turkey that turns against its traditional partners, aligning itself more closely with Damascus, Moscow or Tehran - should be instructive.

Washington needs to make the case to its European allies that delaying Turkey's accession to the EU could harm their security. The longer accession takes, the more likely it is that Turks will become disenchanted with the EU and look elsewhere for opportunities; it is also more likely that Turkey's impressive political reform process, which began in 2002, will stall.

Further, Washington should take a leadership role in working to resolve the Cyprus conflict, which threatens to create further obstacles to Turkish EU membership. Rather than waiting for a new UN or EU initiative on the future of the island, America should catalyze a renewed negotiation process. A special Cyprus coordinator would work with the UN and EU to develop a new plan for reuniting the island, encourage European leaders to use their collective clout to require more constructive behavior from the Cypriot government, and coordinate Washington's political, diplomatic and economic steps to break Turkish Cypriots from their international isolation.

Third, the United States and Turkey should establish a high-level commission that meets twice a year and provides a structured mechanism for interaction across agencies of government, nongovernmental organizations and the private sector. At the outset, three working groups should be launched, focusing on security, economic and commercial ties, and educational and cultural exchanges.

A U.S.-Turkey cooperation commission could facilitate the re-establishment of the sustained interaction that characterizes America's strongest partnerships, and provide a foundation for keeping Turkey aligned with the West should Ankara's bid for EU membership ultimately fail.

As tensions over the outcome in Iraq mount, the prospects for generating positive momentum in U.S.- Turkey relations are diminishing. The consequences of a disoriented Turkey would be even greater than a failure in Iraq. America and Europe must do everything they can to ensure that Turkey remains firmly anchored in the West.

Steven A. Cook and Elizabeth Sherwood-Randall are fellows at the Council on Foreign Relations.

The National Security Agency is a riddle wrapped in a mystery inside a code. Secrets lie within. Located in Fort Meade, Md., it dwarfs the CIA. Its budget is black, unknown. And, most disturbing of all, it is the world's largest employer of mathematicians.

One of its secrets, recently revealed, is that it's monitoring millions of phone calls to learn just who was calling whom. (Technically, only telephone numbers are being recorded, but you don't have to be Q from James Bond to get a name from a number.) This information was being used to determine who might be a terrorist.

Legal or not, the spying program isn't worth violating our civil liberties for. The information one can glean will hardly help us win the war on terror.

With the NSA data, you can draw a picture with nodes or dots representing individuals, and lines between nodes if one person has called another. Mathematicians who work with pictures like this are called graph theorists. The field of social network analysis deals with trying to determine information about a group from such a graph, such as who the key players are or who the cell leaders might be.

But even when you know everyone in the graph is a terrorist, graphs don't contain information about the order or hierarchy of the cell. Researchers look instead for graph features like centrality: They try to identify nodes that are connected to a lot of other nodes, like spokes around the hub of a bicycle wheel. Monterey Naval Postgraduate School researcher Ted Lewis, in his textbook "Critical Infrastructure Protection," defines a critical node to be such a central hub.

There are two problems. First, the central player might not be as important as the hub metaphor suggests. Jafar Adibi of the University of Southern California looked at e-mail traffic between Enron employees before Enron collapsed, and drew the graph. He found that if you naively analyzed the graph, you could mistakenly conclude that one of the central players was CEO Ken Lay's ... secretary. But that wasn't the person who ran the company into the ground.

Second, as the journal Studies in Conflict and Terrorism reported in 2003, you can kill all the central players in a terrorist cell and still leave the cell with a complete chain of command -- still capable of carrying out a devastating attack.

Expert Kathleen Carley of Carnegie Mellon was able to correctly predict -- twice -- who would take over Hamas when its leaders were assassinated, and her analysis used detailed information about the individuals in the organization, not just what anonymous nodes were linked with what. The moral is that the graph theory approach is inadequate. For useful results, it's important to utilize the lattice theory approach, which takes into account order and hierarchy.

The other questionable aspect of the NSA spying program is that it seeks to work out who might be a terrorist based on their calling patterns. While I agree that anyone calling 1 (800) AL-QAEDA is probably a terrorist, guilt by association is not just bad law, it's bad mathematics, for three reasons.

The simplest reason is that we're all connected. Not in the Haight-Ashbury/Timothy Leary/late-period-Beatles kind of way, but in the sense of the Kevin Bacon game. Sociologist Stanley Milgram took individuals unknown to each other, separated by a continent, and asked one person to send a package to the other -- but only by sending the package to an individual he or she knew, who could then only send the package to someone he knew, and so on. While Milgram's interpretation of the results has since been questioned, the conclusion that emerged is that it took only six mailings, on average, for each package to reach its intended destination.

For example, President Bush is only three steps away from Osama bin Laden. And terrorist hermits like the Unabomber might be connected only to very few people. So much for guilt by association.

The second reason the NSA methodology is flawed is the concept "strength of weak ties," made famous by Stanford sociologist Mark Granovetter. Robert Spulak of the Joint Special Operations University puts it this way: You might not see your college roommate for 10 years, but if he were to call you up and ask to stay in your apartment, you'd let him. This is the principle under which sleeper cells operate: There is no communication for years. The links between nodes that the NSA is looking for simply might not exist for the real threats.

Formal concept analysis, a branch of lattice theory, helps rectify this situation. Individuals who share many of the same characteristics are grouped together as one node, and links between nodes in this picture, called a concept lattice, indicate that all the members of a certain subgroup, with certain attributes, must also have other attributes. For instance, you might group together people based on what cafés, bookstores and mosques they attend, and then find out that all the people who go to a certain cafe also attend the same mosque (but maybe not vice versa). While this tool has in fact been used by researchers at Los Alamos National Laboratory to sift through hundreds of terrorism-related reports, it's still dangerous to rely on the math.

The NSA data mining is flawed because, as Kennedy and Lincoln buffs know, two people can be a lot alike without being the same person. Even if there is only a 1 in 150 million chance that someone might share the profile of a terrorist suspect, it still means that, in a country the size of the United States, two people might share that profile. One is just minding his own business. The other is Cat Stevens.

This isn't to say mathematicians are useless. In September 2004 -- 10 months before the July 7 bombing of the London Underground -- mathematician Gordon Woo warned that London was a hotbed of jihadist radicalism. But Woo, who works for the Bay Area company Risk Management Solutions, didn't anticipate the bombings using math. He used his knowledge and experience of London, especially the Wood Green area. That's what law enforcement officials should be doing.

As for tracking terrorist financing, it may already be too late. The terrorism of the future, according to mathematician Stefan Schmidt of the Technical University in Dresden, Germany, may be the terrorism of the futures -- when bombs explode, the stock market drops. Schmidt wants to quantify the impact on the market of a terrorist incident. The only people who know when a bomb will explode are the terrorists. By playing the market, they may already have obtained as much money as they need -- in perfectly legitimate ways -- thus stifling Treasury Department efforts to cut off the source of their funding.

Math is just a tool. Used wisely, math can indeed help win the Battle of Britain (by breaking the German codes). But used unwisely -- as seems to be the case in the NSA telephone caper -- your approval rating might just hit an all-time low.