Is racism universal? Since the end of the colonial era, the rising powers of the developing world have been quick to condemn Western racism. Ethnocentrism and color prejudice can be found in virtually all human societies, going back centuries if not thousands of years.

Yet racism as we know it first emerged in the late 17th century. While slavery is an ancient institution, the racial slavery that took hold in the Americas in that era was new and very unusual. In the English-speaking colonies of North America, the violent subjugation of enslaved Africans created a perverse solidarity among people of European descent, who were united by their place at the top of a racial hierarchy. Racial boundaries that had once been fairly fluid became increasingly rigid. Because the egalitarian ideals of the Declaration of Independence clearly contradicted the still profitable and pervasive practice of racial slavery, it was vitally important that the enslaved be regarded as subhuman, lest the whole corrupt edifice completely collapse.

Even now, Americans are dealing with the scarring effects of this monstrous ideological project. It is also true, however, that Americans have been fairly forthright in confronting this legacy. The same can't be said of the new racism that is taking shape in Asia.

As the late political scientist Samuel Huntington argued, "modernization" and "westernization" aren't the same thing. Economic progress in East Asia and South Asia and Latin America doesn't mean that these regions will become carbon copies of Europe and America. But history has a tendency to rhyme. After decades of breakneck economic growth, South Korea has joined the ranks of the world's richest and most powerful states. As such, a growth model built on cheap labor has been transformed by the emergence of a large and expensive welfare state, and also labor market rigidities that have led to high youth unemployment rates.

Like the rich nations of the West, South Korea also has a low birthrate and, as a direct result, a rapidly aging population. This begs the question of whether South Korea should embrace large-scale immigration. Faced with a similar dilemma, West Germany signed a series of labor agreements in the 1950s and 1960s that led a large influx of guest workers. The idea was that these guest workers would come for a time and then return home. That, of course, is not how things turned out. Over 50 years since the beginning of the guest worker initiative, Germany is still struggling to deal with its growing population of ethnic outsiders. South Korea might have an even harder time.

In a fascinating article published in The New York Times last week, Choe Sang-Hun described the intense discrimination faced by a small but growing number of migrant workers from impoverished Asian countries. A number of Koreans have expressed serious concerns about the end of the country's ethnic homogeneity, arguing that a larger influx of migrant workers would lead to a rise in the level of crime and social tension.

These anxieties have the air of self-fulfilling prophecy. Given that many if not most Koreans prize ethnic homogeneity, migrant workers will remain on the margins of society. This, in turn, will fuel alienation and resentment among this class of permanent second-class citizens. And so South Korea's major cities could very well see the rise of segregated ethnic slums. It's worth noting that anti-foreigner sentiments are flourishing in a time when South Korea is experiencing rapid economic change, including a new social and economic inequality. Just as racism provided the basis for solidarity among whites in U.S. history, it could be playing a similar role in South Korea.

Next to China's race problem, South Korea's pales in significance. Earlier this year, the Center for Strategic and International Studies issued a report that found that the current ratio of 16 retirees to 100 workers is set to double in the next 15 years. In absolute terms, the number of over-65s will go from 166 million to 342 million. Someone will have to care for them, and though China has relaxed its profoundly wrongheaded one-child policy, the reform has come too late to arrest rapid aging.

Moreover, as the political scientists Valerie Hudson and Andrea van den Boer noted in their book Bare Branches, China also has tens of millions of so-called "surplus males" thanks to a strong cultural preference for male children. This means that large numbers of Chinese men will have a difficult time finding wives in the near future. One obvious way for the China of 2025 to address this dilemma would be to embrace mass immigration. Because China remains a poor and populous country, the idea that it will become a magnet for immigrants seems faintly ridiculous, not least because millions of Chinese are desperate to emigrate. Of course, the same was once true of Ireland, which is now one of Europe's most diverse countries.

But like South Korea -- and, for that matter, Japan -- China is not terribly hospitable to ethnic outsiders, including members of non-Han minorities native to China. Observers tend to overstate the level of ethnic homogeneity in China, not least because the Han category masks tremendous cultural diversity. "Hanness" is as broad and contingent a category as "whiteness."

But as Frank Dikötter of the University of Hong Kong argued in his brilliant 1992 book The Discourse of Race in Modern China, traditional notions about culturally inferior "barbarians" intermingled with Western forms of scientific racism to form a distinctively Chinese racial consciousness in the 20th century. The "yellows" were locked in a struggle with their equals, the "whites" -- and both were superior to the "blacks," "browns" and "reds." The dislike and distrust of Europeans was always mixed with envy and admiration. The disdain for dark-skinned foreigners, in contrast, was and remains relatively uncomplicated. Maoist China railed against Western imperialism, and saw itself as a leader of the global proletariat of Africans and Asians.

Now, as China emerges as an economic and cultural superpower, those notions of Third World solidarity, always skin deep, seem to have vanished. It is thus hard to imagine China welcoming millions of hard-working Nigerians and Bangladeshis with open arms. This could change over the next couple of decades as China's labor shortage grows acute. I wouldn't bet on it.

If China remains culturally closed, the Chinese Century will never come to pass. Instead, the United States -- a country that has struggled with race and racism for centuries, and in the process has become more culturally open and resilient -- will dominate this century as it did the last.