Last year, the world learned that France has a problem. The country has failed to socially integrate the descendants of immigrants who arrived in the 1950s and 60s from places like Algeria and Tunisia. Last October, this failure exploded, when hundreds of young, unemployed, mostly African and Arab men rioted, calling for an end to the racial and ethnic discrimination they say runs rampant in French society.

Many historically homogenous European societies are grappling with the problem of how to absorb immigrants and their children. And in the case of Ireland, the issue is shrouded in irony.

In just one decade, Ireland has gone from being a net-exporter, to being a net-importer of people. The country that famously supplied the United States with more than a million and a half immigrants between 1845 and 1860, and which continued to flood America's shores well into the 20th century, is now home to about four hundred thousand immigrants from as far away as China and South Africa.

That is around ten percent of the population, according to Paul Cullen, who writes about immigration for the Irish Times. "It's mostly [because of] economic growth," he says. "The word has gone out around the world that Ireland is a place to find work. And many people have been flocking here to find that work."

It is known as the "Celtic Tiger",  the phenomenal prosperity that Ireland has been enjoying for the last decade. Nowadays, when you visit the Emerald Isle, it is possible you could be staying in a hotel that was built by Nigerian construction workers, and dining at a restaurant where the tables are served by Romanian wait-staff.

The Irish government was flooded with applications for asylum in the mid-to-late 1990s. Paul Cullen says many applicants did not actually meet the United Nation's formal definition of a refugee. They were not facing political persecution in their home countries. But they were poor, and they applied for asylum, because it was the only way to get access to Ireland's abundance.

"It's probably an accepted fact by now that many of the people who came in the 90s to Ireland, many of them were more likely to fall into the category of 'economic migrant,'" Cullen says. "But they applied for asylum, and they relied on the bureaucracy of the system, the slowness of handling the applications, because after all, Ireland had never experienced this before. It had never seen large numbers of asylum-seekers coming to the country."

It took sometimes five years for the applications to be processed, by which point many asylum-seekers had put down roots, found jobs they technically were not supposed to have, and even started families. The Irish government allowed them to stay, because it really did not have the infrastructure to do anything else. And Paul Cullen says the influx has had both positive and negative impacts on Irish society.

"There's no doubt the immigration that we've had has helped fuel our economic boom," he says. "It didn't create it, but it has helped sustain it. The negatives are on the way -- I think it's becoming clear that immigrant workers are holding down wages, and that's been a source of some concern among Irish workers."

It is not the only concern being expressed by native-born Irish. Many resent the fact that asylum-seekers qualify for taxpayer-funded welfare payments. There have been a number of cases of racially motivated violence against immigrants from Africa. And there is common -- though unsubstantiated -- belief in some circles that drug abuse and crime rates have gone up, now that the immigrants have moved in.

It is ironic, because the millions of Irish who fled poverty in the 19th century, and found themselves in cities like Boston and New York, faced similar stereotypes about crime, ignorance, and laziness. And according to Kerby Miller, who teaches Irish-American history at the University of Missouri, Irish immigrants sometimes perpetuated these stereotypes, because their rural poverty had rendered them incapable of handling the rigors of America's disciplined, capitalist society.

"Travelers in  19th-century Ireland thought that the Irish people were not only the most impoverished, but -- from the standpoint of 19th-century capitalist, American values -- the most backward people on the face of the earth," Miller says. "These people, for generations, had had little or no employment. What employment they had was entirely seasonal. You know, you were asking a lot of these people to make the transition to the modern, industrial, capitalist world."

But they did, eventually, make the transition, and today, 15 percent of Americans say they are descended from Irish immigrants - a claim that applies to eight of the last nine American presidents.

Kerby Miller says the fact that the Irish were white had a lot to do with this: racism in America proved to be more powerful than ethnic prejudice. Race has been a factor in the struggle to assimilate immigrants in Ireland, but Paul Cullen says he believes the problem can be dealt with, if Irish citizens are willing to provide the necessary educational and economic resources.

"I think we're in danger of making a very big mistake unless we put a lot of time and effort into getting things right," he says. "We need to make sure that the new communities integrate. Or at least if they don't integrate, that their children integrate, and that they get an equal shake of the stick, they get an equal opportunity in society. If we don't, I fear that we may see all the other problems that have arisen in our European neighbors arise here: the creation of ghettos, antagonism between cultural groups, particularly races."

Paul Cullen says the antagonism has been relatively mild so far, because most people in Ireland are busy making money. But he says he fears what will happen when the economic downturn does eventually come.