SEOUL — The Virginia Tech massacre raises questions and strikes at complexes that go to the depths not only of the Korean-American relationship but also of Korean society and the Korean soul.

One question people ask here is what if some mad American, especially one of those 29,000 American soldiers, whom radical activists want so badly to drive out of Korea, were to go on a similar rampage. No question there.

Hundreds of thousands of Koreans would take to the streets in protests that would go far beyond the peaceful candle-lit outpourings in central Seoul after two schoolgirls were killed by an American armored vehicle nearly five years ago. Americans — and foreigners mistaken for Americans — would not be safe on the streets. American bases would be surrounded by dangerous demonstrators, and the American-Korean military alliance, already badly frayed, could not survive.

That nightmare scenario compares with the absence of an anti-Korean reaction in America to the massacre by a single Korean student whose ravings in his own videotape are a confession of his psychopathic mind. Koreans, however, are bracing for the worst — for a longer term response in which thousands of Koreans, often clustered in their own communities, are exposed to taunts if not acts of violence against Korean stores and shops as well as against Koreans individually, on streets and campuses.

The fact that the killer’s family epitomized the Korean-American success story only deepens the fears — the father, impoverished in South Korea, had gone to America in search of a better life and found it, as the owner of a dry-cleaning establishment that earned enough money for him to own a comfortable two-story townhouse in a newly affluent Washington suburb, to buy a car, and to send both his children to prestigious universities.

Korean fears, raised in emergency meetings in Seoul the moment the news came out of the killer’s Korean origin, are overblown. They spring from the realization of what would happen were a foreigner to perpetrate a similar, or even a much less serious, incident in Korea, from the sense of shame that permeates Korean society — and from deep-seated Korean fears and suspicions of foreigners in general.

If there’s one word, beside total “shock,” that you hear around Seoul, it is the “shame” that the killer has brought to his family, his country, and his people everywhere. On one level, Koreans are constantly saying the incident was “isolated” and not “representative” at all of Korea, while, on another, they’re wondering if foreigners will ever believe them.

The national sense of shame gets at the heart of the homogeneous but fractured nature of Korean society. The country, that is, South Korea, is deeply divided along regional, economic, class, political, and religious lines but united behind a language and a culture whose history, as Koreans are fond of saying, goes back 5,000 years.

It is the desire for national unity that drives Koreans in the South to yearn for reunification with the northern “half” of the country, lorded over by a dictator whose cruel leadership style is reminiscent of that of the Korean kings who ruled for a millennium before the takeover of the whole country by the Japanese a century ago.

The proud sense of Korean culture and history also feeds resentment over the division of the country by the Americans and Russians at the end of World War II as well as anti-Japanese sentiment that is, if anything, more severe than the anti-Americanism of radical groups.

Nor do Koreans forget their historical subservience to China, which continues to exert heavy albeit different forms of influence over both Koreas. As far as many Koreans are concerned, China would prefer to divide and rule rather than see the whole country united as one proudly unpredictable ally.

Korean ethnocentrism takes many forms, ranging from fear and guilt over the madness of one of their own to strange insensitivity. How else to explain a cartoon in a government-owned daily, Seoul Sinmun, that showed President Bush at a press conference saying, “The life of 33 people killed at a time — our excellence of firearms technology was shown again”? After an outpouring of Internet criticism, the editors in their wisdom decided to change the words to, “The murderer was Korean” — a more subtle but scarcely less pointed jab at Mr. Bush, now portrayed as all too glad to pass the blame to Korea.

But many Koreans, in their eagerness to absolve themselves of guilt, have an answer for that one too. The killer, they note, was a member of what’s known in Korea as “the 1.5 generation” — one who was born in Korea, but emigrated at an early age, too young to be considered “first generation” like his parents, but not quite second generation either.

Much talk in Korea focuses on whether he was “really Korean” or “American.” One blogger was quoted as responding with bitter disappointment on learning the killer was not an American citizen but a “resident alien.” This blogger could not believe “someone like me was really involved in this brutal murder.”

But would the killer have been any less like the blogger, or like ethnic Koreans, if he already had a U.S. passport? And does it matter if he was Korean or anything else? Those are questions that some Koreans are raising but not answering while wallowing in a deep grief born more from the killer’s Korean ancestry and for Korean “shame” than from concern for those who died.

Mr. Kirk is a freelance correspondent based in Seoul.