Americans might be forgiven for experiencing a sense of schadenfreude – satisfaction in the misery of others – at the rioting in France. The jihad is coming home, it would appear, to a corrupt French political elite that thought it could appease Muslim extremists by snubbing the United States in Iraq.

America, by contrast, is suffering no such anger in the streets. Around metropolitan Detroit, for example, home to one of the largest concentrations of ethnic Arabs and Muslims outside the Middle East, all is peaceful, despite strongly-held beliefs among community leaders and local imams that U.S. policy in the Middle East is badly misguided.

The reason is fairly clear: Detroit’s Arab-American population, usually estimated at between 100,000 and 200,000, is a model of upward mobility, thanks to auto industry employment in the early days and, more recently, ability to capitalize on its own entrepreneurial energy. Americans of Arab descent have a strong stake in society. In France, by contrast, where overall unemployment has long hovered in the 10 percent range -and at least twice that for the ethnic Arab population – despair and anger are rampant.

To this economic disorder has been added a severe moral disorder: an ideology of multiculturalism that is even more deeply entrenched in Europe than in America. It invites disaffected communities to dwell on their grievances and reject the common values that allow people of differing backgrounds to work together. The multicultural message: somebody else is responsible for your problems.

Before Americans wax too self-congratulatory, however, they should remember that similar forces are afoot here that, if unchecked, could unleash the same social toxins. Stubbornly high taxes and job-killing regulations – including union-backed minimum wage, prevailing wage and “living wage” schemes aimed at preventing willing workers from undercutting union wage levels – make it difficult to sustain the economic growth that mutes social tensions.

And multiculturalism already is the official ideology among American elites: witness the fanatical allegiance to “diversity” within the education, political and business establishments. Virtually every establishment group in Michigan, for example, has already come out against a pending 2006 referendum that would outlaw racial preferences in university admissions and state hiring. Even businessman Dick DeVos, the odds-on favorite to be the Republican candidate for governor, has rushed to distance himself from the measure.

Affirmative action was invented mainly to help African Americans in the wake of the Jim Crow era. But now that official segregation is long behind us, it’s being replaced by the more amorphous goal of “diversity.” Almost any group with a grievance is being invited to join the racial spoils game. Talk about a perfect formula for producing what liberal historian Arthur Schlesinger, in a book attacking the separatism implicit in multiculturalism, termed “the disuniting of America.”

Just as deadly are the taxes and regulations that suppress job formation – or drive it underground, where the jobs can only be filled with continuing streams of illegal immigrants, creating a potentially dangerous underclass like that in Europe. Many on the left and right want to deal with this by enacting tough new measures to seal the southern borders and send the estimated 10 million illegal immigrants already inside the United States packing. It’s likely to be a dominant issue in 2006 and 2008.

But good luck trying to build and effectively patrol a wall along a 2,000-mile border, much less apprehending and expelling millions of Mexicans and others for the sin of taking jobs that in effect are created by government’s burden on the economy. A more cogent immigration policy may be long overdue. But if we don’t also learn the right lessons from Europe’s experience, we may be doomed to repeat it.

Mr. Bray is a Detroit News columnist.