Yo-Yo Ma sat on the edge of the small stage at the Art Institute, his cello resting across his lap.

"See this fingerboard?" the acclaimed cellist asked the audience. "It is made out of ebony, which comes from Africa."

"The red varnish," he said, massaging the body of the instrument, "comes from as far away as Malaysia."

"The hair on the bow comes from Mongolia and the wood of the bow can be found only in Brazil," he said.

Ma's multicultural cello seemed the perfect metaphor for his most recent endeavor: bringing the rich artistic and cultural history of the Silk Road to Chicago Public Schools students.

The Silk Road, the ancient network of trade routes that crisscrossed Eurasia through the 1500s, served as the main conduit for the cultural exchange of goods, art and music. And when Ma sat down and played a soulful partita by Turkish composer Ahmed Adnan Saygun, he showed that cultural exchange enriches the world.

"This is a global instrument," he said. "And by bringing the world together ... beautiful music can be made."

Ma was in town Monday as part of Silk Road Chicago, a yearlong citywide celebration inspired by the art, music and culture along the historic road that stretched from Japan and China through central Asia and into the Mediterranean. The Chicago series is part of the larger Silk Road Project, a multiyear, multicity odyssey created by Ma.

Specifically, Ma spent the day helping introduce a new Silk Road school curriculum to Chicago Public Schools teachers.

Through a collaboration with the Art Institute, 80 Chicago teachers will spend the week discovering the Silk Road and learning how best to explain its importance to students.

"It's sometimes difficult to get students to engage in something that seems so far removed from their lives," explained Gary Mukai, from Stanford University, who helped develop the Silk Road curriculum. "We hope we can help students make a link to their own lives by engaging them musically, mathematically and artistically in the Silk Road history."

Through the lesson plan, students can trace the history of Asia and the West through the important innovations that migrated along the Silk Road. Students will learn that gunpowder, the magnetic compass, lacquer crafts and, of course, silk, flowed from East and West and back.

Musical forms and instruments also traveled the Silk Road, as string, wind and percussion instruments from the East and the West influenced each other. Cymbals were introduced into China from India. The Chinese gongs traveled to Europe. And the Persian mizmar, a reed instrument, seems to have been the ancestor of the European oboe and clarinet.

Ma implored the teachers to reach out to students and help create a "spark" that will open their minds to the "amazing cultures around them."

"As teachers, you are incredible guides into a world that you can make a most exciting place," he said.

The Silk Road is a metaphor that "joins us together not only in material things but in spiritual ways," he said. "You can translate that to your students."

Don Gibson, a music teacher from Dyett High School on the South Side, said the Silk Road will help him incorporate history lessons into his music courses.

"Through the Silk Road music lessons, I can broaden their understanding of cultures and the history of those cultures," Gibson said. "To be inspired by the music, sometimes, you have to know its history."

READER CONNECTION
Would you like to learn more about the Silk Road Chicago events? Visit the Silk Road Project.

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.

Koreans have developed a sense of nation based on shared blood and ancestry. The Korean nation was "racialized" through a belief in a common prehistoric origin, producing an intense sense of collective oneness. Ethnicity is generally regarded as a cultural phenomenon based on a common language and history, and race understood as a collectivity defined by innate and immutable phenotypic and genotypic characteristics.

But historically, Koreans have not differentiated between the two. Instead, race served as a marker that strengthened ethnic identity, which in turn was instrumental in defining the nation. Koreans thus believe that they all belong to a "unitary nation" (danil minjok), one that is ethnically homogeneous and racially distinctive.

Despite 1,000 years of political, linguistic, and geographic continuity - and contrary to popular belief - this sense of ethnic homogeneity took root only in the early 20th century.

Faced with imperialist encroachments, Koreans developed the notion of a unitary nation to show its autonomy and uniqueness. They stressed the ethnic base, rather than civic elements, in defining the Korean nation.

Shin Chae-ho, a leading nationalist, for instance, presented Korean history as one of the "ethnic nation" (minjoksa) and traced it to the mythical figure Dangun. According to him, the Korean people were descendants of Dangun Joseon, who merged with Buyo of Manchuria to form the Goguryeo people. This original blend, Shin contended, remained the ethnic or racial core of the Korean nation, a nation preserved through defense and warfare against outside forces. The nation was defined as "an organic body formed out of the spirit of a people ... descended through a single pure bloodline" that would last even after losing political sovereignty.

The need to assert the distinctiveness and purity of the Korean nation grew even more important under colonial rule, especially as Japan attempted to assimilate Koreans into their empire as "imperial subjects." The Japanese assimilation policy was based on colonial racism, which claimed that Koreans and Japanese were of common origin but the former always subordinate.

The theory was used to justify colonialist policies to replace Korean cultural traditions with Japanese ones in order to supposedly get rid of all distinctions and achieve equality between Koreans and inlanders. Colonial assimilation policy included changing Korean names into Japanese, exclusive use of Japanese language, school instruction in the Japanese ethical system, and Shinto worship.

Koreans resisted by asserting their unique and great national heritage. Yi Kwang-su, a key figure during colonial rule, claimed that "hyeoltong" (bloodline), "seonggyeok" (personality), and "munhwa" (culture) are three fundamental elements of a nation and that "Koreans are without a doubt a unitary nation (danil han minjok) in blood and culture." Such a view was widely accepted among Koreans: To impugn the natural and unique character of the Korean ethnic nation during colonial rule would have been tantamount to betraying Koreanness in the face of the imperial challenge of an alien ethnic nation. Japanese rule did not erase Koreans' national consciousness but rather reinforced their claim to a truly distinct and homogeneous ethnic identity.

After independence in 1945, and despite peninsular division into North and South, the unity of the Korean ethnic nation or race was largely taken for granted. Neither side disputed the ethnic homogeneity of the Korean nation, spanning thousands of years, based on a single bloodline of the great Han race. Instead, both sides contested for the sole representation of the ethnically homogeneous Korean nation. Even today, Koreans maintain a strong sense of ethnic homogeneity based on shared blood and ancestry, and nationalism continues to function as a key resource in Korean politics and foreign relations.

Ethnic national identity has been a crucial source of pride and inspiration for people during the turbulent years of Korea's transition to modernity that involved colonialism, territorial division, war, and authoritarian politics. It has also enhanced collective consciousness and internal solidarity against external threats and has served Korea's modernization project as an effective resource.

At the same time, such a blood-based ethnic national identity became a totalitarian force in politics, culture, and society. It came to override other competing identities and led to the poverty of modern thought, including liberalism, conservatism, and radicalism. It has hindered cultural and social diversity and tolerance in Korean society.

Ethnic nationalism will remain an important organizing principle of Korean society. We cannot ignore ethnic national identity or treat it as a mere myth or fantasy. But neither can we remain simply content with its current role.

Instead, it should be recognized that ethnic nationalism has become a considerable force in Korean society and politics and that it can be dangerous and oppressive when fused with racism and other essentialist ideologies. Koreans must thus strive to find ways to use ethnic nationalism constructively and mitigate its potential harmful effects.

In particular, Koreans must seriously consider the establishment of a democratic

institution that can contain the repressive, essentialist elements of nationalism.

The principle of bloodline or "jus sanguinis" still defines the notion of Korean nationhood and citizenship, which are often inseparable in the mind of Koreans. In its formative years Koreans developed the ethnic base of nation without a corresponding

attention to the political notion of citizenship.

After colonial rule, neither state paid adequate attention or made any serious effort to develop a more inclusive notion of citizenship. Social institutions that can address issues of discrimination against ethnic non-Koreans (for example, ethnic Chinese known as "hwagyo" in Korea) have been largely overlooked. The Korean nationality law is still based on jus sanguinis and legitimizes, consciously or unconsciously, ethnic discrimination against foreign migrant workers.

In this context, most Koreans have stronger attachment to "ethnic Koreans living in foreign countries" than to "ethnic non-Koreans living in Korea." It is also much easier for a Korean-American who supposedly has "Korean blood" to "recover" Korean citizenship than for an Indonesian migrant worker living in Korea to obtain Korean citizenship. This is true even if the Indonesian worker might be more culturally and linguistically Korean than a Korean-American.

Korea needs to institutionalize a legal system that mitigates unfair practices and discrimination against those who do not supposedly share the Korean blood. Koreans need an institutional framework to promote a democratic national identity that would allow for more diversity and tolerance among the populace, rather than simply appeal to an ethnic consciousness that tends to encourage false uniformity and enforce conformity to it.

They should envision a society in which they can live together, not simply as fellow ethnic Koreans but as equal citizens of a democratic polity. It should be an integral part of democratic consolidation processes that Korea is currently undergoing. Otherwise, it would be hard to expect Korea to become "Asia's hub," which will require the accommodation of cultural and ethnic diversity and flexibility.

Discussion of unification is premature and can even be considered dangerous if unification occurs without such change. As the German unification experience shows, a

shared ethnic identity alone will not be able to prevent North Koreans from becoming "second-class citizens" in a unified Korea. Even worse, because of higher expectations resulting from a shared sense of ethnic unity, a gap between identity (ethnic homogeneity) and practice (second-class citizens) will add more confusion and tension to the unification process.

Thus, it will be a major challenge for Koreans to develop democratic institutions that can treat people living in Korea as equal citizens of a democratic polity. This task will be all the more important and urgent as Korea becomes more democratic, globalizes, and also prepares for national unification.