A COUPLE OF weeks ago on a network news program, an American correspondent asked a middle-aged Serbian peasant woman in Bosnia why she was willing to continue this war against her Muslim neighbors. "It is better to die in battle than to live in shame," she responded quickly as if the answer had been rehearsed. For most, these words probably meant nothing other than one more sign that the ugly conflict in the former Yugoslavia is impossible to understand.

Certainly the correspondent had no idea that this woman had just recited a line from the Serbian medieval epic tradition. In those few words she not only summarized 600 years of Serbian history but articulated the very heart of the fanaticism that accompanies Serbs in their current war.

For this woman and for most Serbs, the war in Bosnia is simply one more battle in a long struggle that began six centuries ago in a battle on the field of Kosovo in southern Serbia. They are driven by a conviction that the war is just and that it will not end until all Serbs are safely united in one state and the territory of Kosovo is permanently under Serbian control.

The importance of Kosovo was clearly in President Clinton's mind when he suggested that the region is a tinderbox that could ignite a general Balkan war. This concern was obviously behind last week's decision to send U.S. peacekeeping troops to Macedonia in order to guard against a widening of the war; the small contingent will be the first American soldiers in former Yugoslavia. Secretary of state Warren Christopher, told NATO ministers last week that the conflict in Bosnia "must not be allowed to spill over."

If the Balkan war spreads to the territory of Kosovo, as most Western observers fear, it is imperative that the West understand the mythical power of Kosovo in the historical and national consciousness of the Serbian people. It should know why Serbs around the world will defend Serbia's right to protect its "Jerusalem."

Indeed, for the Serbs, Kosovo has long been the symbol of the moral apotheosis of the Serbian people, chosen by God as "the new Israel." The Battle of Kosovo, on June 28, 1389, which precipitated the conquest of Serbia by the Ottoman Turks, came to be seen as the source of all the misfortune Serbia was to suffer during centuries of subjugation to the Muslim Turks.

And whether we like it or not and regardless of some of its irrationality, the Serbian position today is clear. For Serbs who are fighting in Bosnia and for those Serbs who support them in what is left of Yugoslavia, this war is no different from their struggle against the Turks over the centuries.

Many of the Serbs firing randomly at innocent citizens in Sarajevo, burning entire Moslem villages and "cleansing" areas of non-Serbs are convinced that they are following the Kosovo ethic. The true believers are in fact certain that they have been given the responsibility to bring a final solution to their long history of oppression, martyrdom and separation. In their view, one great Serbian state and its largely Orthodox population, liberated from Catholics and Muslims, will never again have to face the agony of its long and troubled history.

Over the centuries, the cult of Kosovo evolved to celebrate martyrdom on the one hand but also to demand of all generations of Serbs that they avenge the loss of Kosovo and liberate all Serbs from oppression. During Ottoman rule, which lasted until the early 20th century, the Serbs believed that God would protect His people and return them one day from their captivity. They also came to believe that there can be no free state without a struggle. Their epic poetry idealized those who sacrifice themselves in order to strike a blow against the oppressor. In the words of the epic: "Whoever is a Serb and of Serbian blood and comes not to fight at Kosovo . . . Let nothing grow from his hand . . . until his name is extinguished forever."

In the 19th century, as Serbia gradually liberated more of its land from Ottoman control, the primary prize remained Kosovo itself. As the center of the medieval Serbian state with some of its oldest churches and the first Serbian patriarchate, Kosovo was indeed Serbia's Jerusalem.

Kosovo was finally taken from the Turks during the Balkan Wars of 1912-1913. Consider the recollections of one of the young Serbian soldiers in those wars when he was told that his unit would liberate Kosovo: "The single sound of that word -- Kosovo -- caused an indescribable excitement. This one word pointed to the black past of five centuries. In it exists the whole of our sad history . . . . Our mothers lulled us to sleep with the songs of Kosovo, and in our schools our teachers never ceased in their stories of it . . . . We feel strong and proud, for we are the generation which will realize the centuries-old dream of the whole nation: that we with the sword will regain the freedom that was lost with the sword."

Unfortunately for Serbian interests, the Kosovo that they liberated on the eve of World War I was not the same territory they lost 600 years earlier. Over the centuries it had become home to a very large population of Albanians.

Still, after the war, Serbs migrated to Kosovo. For the Albanian population, Serbian policies in Kosovo were generally repressive. As a result many Albanians hoped that World War II would bring them liberation from Serbian control. That, of course, did not happen, and in Tito's new socialist Yugoslavia, Kosovo remained a part of Serbia.

In the meantime, Albanians in Kosovo only continued to increase, achieving the highest birthrate in postwar Europe. By 1974 Albanian demands for more autonomy were reflected in the new Yugoslav constitution that recognized Kosovo as an autonomous province in the Yugoslav federation. Tito was said to argue that a weak Serbia would guarantee a strong Yugoslavia, and taking direct Serbian control away from its most sacred territory was clearly designed to encourage that goal.

Not long after Tito's death in the spring of 1980, Albanian voices in Kosovo began to agitate for republic status for their province in the Yugoslav federation. And the Serbian population in Kosovo began to feel the effects of repression by the preponderant Albanian population. Thousands of Serbs left Kosovo in a steady migration that was interpreted by Serbian leaders as an attempt at ethnic cleansing on the part of the Albanians. The non-Albanian population of Kosovo decreased to no more than 15 percent of the region. The continued demonstrations and agitation in Kosovo led to the imposition of martial law in the region, the imprisonment of thousands of Albanian dissidents and the presence of the Yugoslav army, which remains there to this day.

The conflict in Kosovo eventually played into the hands of a relatively young and ambitious Serbian politician named Slobodan Milosevic. In April 1987, Milosevic traveled to Kosovo and put himself on the line as the defender of all Serbs. In a now-famous speech he admonished his compatriots to stay in Kosovo and fight:

"Migration under economic and physical pressure may represent the last tragic exodus of a European population . . . . Therefore, in line with our goals, I want to say to you, comrades, that you must remain here. This is your land. Here are your homes, your fields and gardens, your memories. I assume that you will not leave your land because it is difficult to live on it or because injustice and humiliation oppress you. It has never been characteristic of the soul of the Serbian and Montenegrin people to succumb to obstacles, to demobilize just when you have to fight, or to become demoralized when things are difficult. You must remain here because of your ancestors and your descendants . . . . "

Milosevic's success was immediate. In the spring of 1989, playing on the hypernational sentiments of Serbs, Milosevic virtually abrogated the autonomy Kosovo had enjoyed since 1974 and returned the province to direct Serbian control. It was, therefore, a strong and unified Serbia that eagerly prepared for the commemoration of the Battle of Kosovo. And Milosevic was more than ready to manipulate that national sentiment as he headed south to Kosovo once again on the 600th anniversary -- June 28, 1989.

Milosevic was the only speaker that day when more than 2 million Serbs from Yugoslavia and around the world gathered on the famous battlefield to reclaim their destiny.

Why did we lose the battle on Kosovo? Milosevic asked the multitudes. It was because of disunity and betrayal, which then followed the Serbian people like an evil fate throughout their history. He blamed Serbian political leaders for holding Serbia back and accepting an inferior position for it in the Yugoslavia federation. But he went on record to say that Serbia was not going to stay down any longer. And what better place to make that declaration, he argued, then on the historic field of Kosovo where Serbia may have lost a great battle but won a shining moral victory? In light of today's tragic conflict, it is interesting to note that Milosevic also suggested that a strong Serbia would guarantee the prosperity of all its citizens -- whether Serb or other. He noted that the presence of many different ethnic groups in Serbia contributed to its great advantage, because in the most advanced countries of the world citizens of various national groups, religions and races live and prosper together. And then in a moment of prophetic irony, Milosevic warned that the division of Yugoslavia into national units would be a disaster: "Like a sword over our heads is the unending threat . . . of one ethnic group's endangerment at the hands of others . . . . {This will} set in motion a wave of doubts, accusations and intolerance which will grow and be difficult to suppress."

At the same time he admonished his compatriots to remember that they were again engaged in battles. And while he reminded the crowds that these were not armed battles, he did not rule out the use of force. Moreover, it was clear that he accepted the myth of Serbia as defender of Europe against the infidel: "Six centuries ago Serbia defended itself on Kosovo, but it also defended Europe. She found herself on the ramparts for the defense of European culture, religion and European society as a whole."

Since that day, Serbs have not failed to remind themselves and the world that they are fighting for the very defense of Europe against Islamic fundamentalism. It matters little to them that Europeans and Americas do not perceive any need for defense.

All of this is a reflection of Serbia's obsession with the spirit of Kosovo -- a timeless spirit that changes very little from one generation to the next. One hundred and four years ago, as the Serbs celebrated the 500th anniversary of their inspired battle, the Serbian minister of foreign affairs explained the meaning of Kosovo to the world: "An inexhaustible source of national pride was discovered on Kosovo. There was never a war for freedom -- and when was there no war? -- in which the spirit of the Kosovo heroes did not participate. The new history of Serbia begins with Kosovo -- a history of valiant efforts, long suffering, endless wars, and unquenchable glory . . . "

It is this spirit that makes the world nervous about Serbia's intentions in Kosovo today. For the time being, the Albanian population there has not mounted an armed resistance to martial law. If they were to do so or if the government in Belgrade were to encourage the ethnic cleansing of the province, there is little doubt that the war in the Balkans would spread beyond the borders of the former Yugoslavia. The new leadership in Albania (and President Clinton for that matter) has made it clear that it will not stand idly by if Albania's co-nationals in Kosovo become the next victims.

Santayana's admonition that those who fail to study the past are condemned to repeat it has, perhaps, its own ironic twist when used to examine the Serbian experience. In the case of Serbia one might be compelled to argue that those who study the past too much are simply entrapped. The Serbs, and to a great extent the Croats and Bosnian Muslims, have become prisoners of history. How else can we understand the sentiments of an 18-year-old Serbian irregular soldier in Bosnia who claims to be the final avenger of Kosovo?

In the late 20th century, we may find it impossible to understand a society in which the medieval past is still an operative force in people's lives -- people who hear the princely exhortation from the Kosovo epic as clearly as if it had been spoken yesterday: "Whoever is a Serb and of Serbian blood and comes not to fight at Kosovo . . . " But as the world turns its attention to Kosovo in the coming months, it would be well to remember that the myth of Kosovo is a key to understanding Serbia and its objectives. Tragically, the spirit that once defined a noble cause of liberation has become for many a delusion with ominous consequences for the stability of southeastern Europe.

Thomas Emmert, a history professor at Gustavus Adolphus College, is the author of "Serbian Golgotha: Kosovo, 1389."