That first time coming into New York after the destruction of the Twin Towers, the sentiment was moving; and the words remain a statement of American resolve; but, in a very important sense, the assertion of unity rings false.
   

However strong the common purpose in the current campaign against rogue Arab groups, the US is very gradually fragmenting. That statement may appear perverse, at a time when the US is at the peak of its power. Nevertheless, on a recent road-trip from San Francisco to New York, I was struck most by the observation: Americans are evolving apart from eachother.
   

I have led a sheltered existence in the United States. In five years of living and traveling in the United States, I have clung to the coasts. Sure, there was the conference in Austin, Texas, and another in Scottsdale, Arizona, but those two towns are enclaves of California, and do not count.
   

My only other experience of middle America - Wisconsin, Nebraska, Iowa, Wyoming and all the other flyover states - was from a safe distance of 35,000 feet. I would look down at the empty land, remember that, on 19th century maps of North America, the area was called the Great American Desert, and check how many hours more to San Francisco.
   

It was as if I was setting out across the desert when I left San Francisco. Acquaintances bombarded me with helpful advice, most of which involved plotting the shortest route across the cold and the barren. Paul Pedersen, a Silicon Valley software architect, advised me to avoid the states where schools taught creationism over evolution: Carolinas good, Virginia bad.
   

Go the southerly route, that was the consensus view. Santa Fe is great, and from there you just have to make it through northern Texas, Oklahoma and Arkansas, before you get to Tennessee and civilization. Well, if not civilization, at least Elvis.
   

And some people, like Raymond, the camp German owner of a boutique hotel just above the Sunset Strip in Los Angeles, simply failed to understand what possessed me. "For me, the US is LA, New York, San Francisco, maybe New Orleans. The rest: you can keep it."
   

I already knew from the movies and the newspapers that middle America would be different, of course. The inhabitants: redneck cops, slow hillbillies, desperate smalltown intellectuals - cheap but funny stereotypes. The places: Waco, Laramie, or Columbine - the dateline from the latest massacre.
   

When I tried to delve beneath the cliche, I would read the occasional anthropological study in the New York Times on the strange culture of the heartland. An evergreen topic refreshed by the latest Christian rock phenomenon, or a novel such as Bridges of Madison County that emerged out of nowhere - middle America, that is - to dominate the bestseller list.
   

And from close up? The high production values of an anti-abortion ad on Christian radio; a fragment from the right-wing talk radio show, we're a fat and happy country being gutted by the wolves, the immigrants; Christian graffiti - "Trust Jesus" - in Virginia; having to order a "lady's steak" and splitting it between two of us, because neither of us were meat-eating middle American male.

   

The differences in America were displayed in a tidily shaded map during the November 2000 election: the Pacific and East Coast states a solid Gore blue, bracketing the Bush red of middle America. The more detailed county-by-county maps of election results showed the blue liberals like a fringe around the coasts, being pushed into a few urban enclaves and the sea by the real America. Of course George W. Bush was indifferent to global warming, when a rise in sea levels would largely inundate the America which voted for his opponents.

   

To be sure, the divide between liberal coasts and conservative heartland is more obvious now in part because other political issues have disappeared. There is broad consensus over economic and foreign policy; and the political legacy of the civil war, the strange alliance between Northern liberals and Southern segregationists, has expired. All that is left, as one character says on the West Wing television show: one corporate party, with a pro-abortion and anti-abortion wing.

   

And, it is more commonly the homogeneity of the US that strikes a visitor. Driving along the US interstate highway system is like the movie Groundhog Day, in which the hero is condemned to repeat every day: a strip of Macdonalds, Home Depot, and Walmart, endlessly repeated. The few pathetic retail variations I noticed: In 'N' Out burgers in California and Arizona, the Waffle House in Arkansas, and one genuine diner we stumbled upon at an exit in mid-Tennessee.

   

As the South develops, and Northerners move in, cities such as Atlanta are becoming more liberal. The last census showed Latinos and other minorities making their way into previously white areas. Intermarriage, at least between Asians and whites, or between Jews and non-Jews, runs as high as 50%.

   

But the divide is no longer so much ethnic as cultural. Americans are evolving apart. The US has always catered to cultural defectors from the mainstream. The rich in their gated communities, some so exclusive that they are located in other gated communities; pensioners in southern Florida condos; gays in San Francisco's Castro neighbourhood; north European protestant sects in rural Pennsylvania.

The difference now is that entire regions, not just enclaves, are going their own way. Cities, even the largest, have specialized. Entertainment in Los Angeles, technology in San Francisco and Silicon Valley, publishing and finance in New York; and each of these industries attracts a certain type of person. With people so easily able to rent a U-Haul truck, a new apartment, and trek across the country, it does not take long for like spirits to collect in these city-states.

   

I am moving from San Francisco to New York in part because I want to be witty without being thought rude. Even the goys in New York behave Jewish; West Coast Jews, as one LA screenwriter observes, have become blond and bland within two generations, as if sand got into their DNA. Inhabitants of Silicon Valley are smart, earnest and awkward. Los Angelinos do indeed take more care over their appearance, and they are more attractive. Southerners are loud and friendly. And, yes, middle Americans are fatter; the sterotype, like most others, is true.

· United? The US is turning into a nation of city states [short version, with awkward edits, in Management Today] #