Paul Smith is as big in Tokyo as he is in London; American and Chinese children are brought up on a similar diet of Nintendo and MTV; it costs as much to e-mail Cape Town as Clapham; a downturn in the Japanese economy leads to job losses in Galashiels. We live in an incredibly shrinking world.
At first sight, nothing seems to provide a better illustration of this process than the way we eat. It takes 10 minutes to walk from my house to the nearest supermarket. Doing so I pass two Chinese restaurants, one Indian, one Thai, one Japanese, two pizzerias, an Italian trattoria and George and Niki's Golden Grill ("Traditional English Food"). In the supermarket itself, past the sugar-snaps from Zambia, the strawberries from Portugal and the blueberries from America, the ready-made meals section offers a choice between shepherd's pie, duck confit, lasagne, spring rolls and prawn masala and rice. Waiting at the check-out, I pick up the supermarket magazine; it offers recipes for Irish stew, Indian paratha, and Asian stir-fry noodles. Traditionalists, foodies and aesthetes may wring their hands, but this is the way we eat now.
You'll have noticed, though, that I said "at first sight". This is because close-up, the globalisation theory reveals serious flaws when it comes to food. In fact, if the expedition just described shows anything, it is that this diversity of cuisines represents the opposite of a homogenised, hi-tech culinary culture.
When it comes to choosing what to eat, we want to be able to take our pick from anywhere in the world, but we want local, regional, at least national cuisines, and we want them to appear "authentic". While we are spoilt for choice, we choose cuisines that have evolved from necessity, making a virtue of a limited range, their ingredients and methods often restricted by economy and the seasons.
Our food cupboards are full of things our grandparents had never heard of. Olive oil ("Isn't that for earache, dear?"), papaya ("A place near New Guinea?"), Amoretti ("A little love song?"). The odd thing is though, we are chary about mixing too many of these components: the fish sauce tends to come out when we are cooking Thai, not Spanish; olive oil goes with pasta, silly, not with Chinese noodles. For all our freedom, we prefer to stick to the conventions, working within traditions, even if they are other people's. It's a rare cook who mixes cuisines on the same plate.
In this way food still differs fundamentally from fashion or design. In these disciplines, the vernacular has almost completely disappeared, replaced by an international aesthetic. Students of design and architecture aren't usually schooled in distinctively national styles and/or traditional techniques - Prince Charles' suggestion that they should be was, to put it mildly, controversial. You would be hard put to know that, for example, Norman Foster's Hong Kong & Shanghai Bank was designed by a British architect for a Chinese client, or that the Guggenheim museum in Bilbao was to be built in Spain.
Now think of food. I have just pulled out four cookery books, more or less at random: Raymond Blanc's Recipes from Le Manoir aux Quat' Saisons, Vatch Bhumichitr's A Taste of Thailand, Madhur Jaffrey's A Taste of India and a new one, Paul Heathcote's Rhubarb and Black Pudding. They all begin in exactly the same way: the author pays homage to the cooking of the family, the region, the country from which he or she comes, evoking its traditions in loving, slightly nostalgic detail. This is how many recipe books begin, as sure as Mills & Boons end in marriage.
Where good cooking is concerned, novelty takes second place to authenticity. Or at least, we want originality within a fairly narrowly defined set of limits. The restaurants we tend to like are those that have a strong sense of place - that understand how to manipulate and enrich established conventions, rather than those that boldly jettison them.
Go to Terence Conran's Butler's Wharf. His Design Museum is an exercise in cool, white, international modernism, in perfect keeping with the timeless, placeless, technologically advanced objects it exhibits. The building and the things in it all speak the same language - a visual Esperanto. Yet go to his restaurants next door - La Pont de la Tour, the Cantina del Ponte, the Butler's Wharf Chop House - and you enter a place of historic locality, each one piously gesturing to one national cuisine or another.
You will find a similar paradox if you go to go to Mies van der Rohe's famous Seagram building in New York. The ground floor of this "International Style" masterpiece houses the Four Seasons restaurant serving traditional Italian fare - and the same people that admire the building enjoy the restaurant.
Even French haute cuisine, which aspires to a perfection beyond time or place, is in fact intensely backward-looking. Every great French chef, from Escoffier to a leading exponent of nouvelle cuisine like Paul Bocuse has claimed that his manner of cooking alone gives authentic expression to the nation's traditions. It is now rare for any Paris restaurant to succeed without presenting itself as a "regional" spot - as a south-west or Provencal place.
Our attitude to what we eat betrays something surprisingly atavistic: we want our food rootsy - although we don't seem to mind if they are someone else's roots. When we buy a car, we want efficiency, safety, sleekness, state-of-the-art technology, these are the things that matter. But when we buy a meal, we suddenly go sentimental. We want Spanish food like Spanish peasants eat, or "real" Indian cooking.
Think how rare it is that we see the emergence of a genuinely new dish - something simply invented. Our sandwich-fillers - humous, "tara", mozzarella, gravad lax and the rest - might retain only the faintest similarity to the original, but we want none-the-less to feel that they have pedigree.
Looked at in the cold light of day, our hankering after authenticity seems vaguely irrational. Why not just shrug it off, along with the watch chain, the running board, the sash window and similarly outdated contraptions? We could survive more cheaply and healthily on an astronaut's diet. Yet we are not and don't aspire to be entirely rational creatures - few subjects, in particular, are more invested with metaphor and shrouded in taboo than the food we eat. We possess this almost unconscious but ineradicable conviction that cooking should show a feel for tradition; that eating is not just a matter of hunger and its satisfaction, but of culture - that there is history and ecology to be taken into account. Who would have guessed that we are so sensitive? .