'I believe in America. America has made my fortune". The opening lines of The Godfather are not the rhetoric of some Aryan super-patriot, but the words of an Italian immigrant, barely able to speak English. They could equally have been uttered by the putative governor of California, Arnold Schwarzenegger. Or by my own father. After years of low-status employment in London, the Powellite menace of the late 60s drove him to the US. Late in life he fulfilled a modest version of the American dream, a white-collar job on a university campus. So I, too, believe in America. But adult passions pass unless you can also embrace their imperfections.
America's most abiding failure has been an inability to erase the racial divisions etched in its social DNA; its defining success has been a genius for embracing and exploiting the economic potential of a continuous stream of immigrants. By contrast, Europe trembles at a level of migration that Americans would regard as piffling. Yet from Rome, through Constantinople to Venice and London, our nations have a history of peacefully absorbing huge, diverse movements of people, driven by war, famine and persecution; and there is no history of long-term ethnic segregation of the kind one can see in any US city.
That is why it is so exasperating when friends return from their summers on Martha's Vineyard or in San Francisco, enthusing about the success of minority Americans. I know that we home-grown black folk can't aspire to the glamour of some Americans - Colin Powell, Condoleezza Rice or my great friend from Harvard, Skip Gates, who has become a BBC TV star. But our lack of celebrity should not blind intelligent people to a few basic truths.
First, on race equality, America has failed in every way possible. The small group of successful black professionals and the ghetto-fabulous gangsters who turn up on our TV screens loom too large in our picture of the US. For the average black or Latino American, life is better than it was; but the gap between minority households and whites continues to grow every year, in terms of employment, education and health.
Those who do succeed outside of entertainment and sport do so only and exclusively through two routes, both of which are widely regarded with distaste by Europeans. One is contract compliance, in which both the government and big private sector companies are, in effect, compelled to give a proportion of their work to minority entrepreneurs. I have yet to learn of a black millionaire who has not benefited from this provision; I have yet to meet a white liberal who does not feel uneasy about it.
The other route is affirmative action. Powell, Rice and Gates all state baldly that they would never have reached their current eminence without positive discrimination at some stage in their lives. In his single public disagreement with the president, Powell cited his own successful military career to argue why American universities should retain the right to use race as a factor in admissions policy. Affirmative action alone accounted for most of the black senior American faces we saw in Iraq.
So everyone who yearns for a "British Colin Powell" should think about what they are signing up to - if they are serious. Politicians could signal support for contract compliance by handing the production of their next party political broadcast to a black production company, or the printing of their manifesto to an Asian firm. Or they could just select some black or Asian parliamentary candidates for safe seats.
This summer has brought a new discovery: multiracial America, or as Timothy Garton Ash called it in these pages last week, "Californication". Visiting Stanford University, he has been bowled over by a student body "sporting every shade of skin colour" and representing a spectrum of ethnic combinations. This, he declares, offers "the ultimate answer to the problem of racial difference". How can someone so galactically brainy put his name to this tosh? In the 1970s some of my fun-loving student comrades advocated the left's cause through what we called the "horizontal road to socialism". The difference is that we thought substituting sexual congress for the trade union version was a joke.
The truth is that even in liberal California, racial mixing is still a rarity. More than 30% of the US population is either black, Asian or Latino. Statistically, if Americans chose their partners at random, more than a third of American births should be of mixed race. The figure is, in fact, just 1.6%. Here, it's about 1.1%. But to count inter-racial sex as a reliable indicator of good race relations you'd have to write off the entire history of slavery in America; there was probably more miscegenation on the plantations than at any time in human history. Even if you were silly enough to confuse sexual intercourse with social integration, we still beat the pants off the US. In Britain, up to half of all marriages involving a black man are with a white partner - and "mixed" is now the fourth largest group in the population, after white, Indian and Pakistani.
Of course, the Brits have been at it longer. Two centuries ago, there were some 20,000 to 30,000 black Georgians in London, so familiar they got a name - the Blackbirds of Covent Garden. Yet four generations later, a black face was unusual in London, because the blackbirds had produced so many mixed-race chicks. And it's worth reminding ourselves that Americans have a unique way of discouraging inter-racial relationships: US papers were last week reporting yet another mysterious hanging of a black man alleged to have been in a relationship with a white woman.
Yet American liberals glow with pride over Muslims who wear hijab but speak with authentic American accents. In the university where one of my relatives taught I would lay a penny to a pound that, given the $40,000-a-year fees, these students were more likely to be Saudi princesses who learned their Valley Girl English at exclusive private schools than the daughters of Arab-American shopkeepers from Michigan. For the real thing, you're better off going to any college in Oldham or east London, where the clothes may be imported from Pakistan or Bangladesh, but the accents are pure Coronation Street and Albert Square.
The place where Americans do have something to teach us is on immigration and asylum. They aren't perfect, but I would happily exchange our miserable and mean-spirited attitude to migrants for their energetic pursuit of talents and energy from everywhere in the world. Great Britain was created out of the vitality of a multiracial, polyglot empire, but we kept our subjects at arm's length. The Americans are less fussy about who they let through Ellis Island. They raid the world for the best and the brightest and turn them into Americans with hi-tech jobs and green cards. Instead of being dazzled by the few bright sparks in America's racial nightmare, Europe should be working out how we can copy the real success at the heart of the American dream.
· Trevor Phillips is a journalist and broadcaster. Since March 2003 he has been chairman of the commission for racial equality
© Guardian Newspapers Limited 2003