WE ALL know about the exponential rise in travel and tourism that has taken place over the past 15 years.

Statistics keep telling us that tourism is going to be by far the world's leading industry. Bookshops contain nothing but guidebooks. Newspapers bulge with travel pages. People I know take one holiday in Spain in the summer, another in the Caribbean at autumn half-term, a skiing trip in Colorado in the winter, a spontaneous long weekend in eastern Europe in February and then a couple of weeks backpacking for old time's sake down the Mekong river in the spring, before heading off on safari.

We are led to believe, in fact, that it won't be long until most of the world's income is being spent on holidays. Cars, dishwashers, mortgages, new bathrooms etc will come out of the small change left over from our annual super-deluxe round-the-world themed cruises.

Or will they? Recent events make me wonder whether we might one day look back with amazement on that brief decade when the entire world briefly opened up its doors to happy, wealthy foreign travellers. It's not just that Russian tourists in Limassol are suddenly finding that they cannot use their credit cards. Every time I switch on the news I hear about an imminent global slump. East Asian airlines are closing routes and cancelling orders with Boeing. Occupancy rates in Hong Kong hotels have crashed. Craftsmen in Bali and Thailand are virtually having to pay rich Westerners to take away their engraved tabletops.

The other thing is that I keep hearing reports of British tourists being bumped off in remote parts of the world. At least one Briton dies abroad every day of the year. But a serial killer on the loose in a place called Paradise Island of all places? And the British detective sent to investigate the case being robbed within hours of his arrival on the island? If you can't tour the Bahamas without fearing every rustle in the trees then perhaps we had better spend a few decades at home.

Then there are bombings in South Africa and Sri Lanka, with dead tourists presumably the intention. We saw last year in Egypt what a conveniently soft target the tourist can be. In Algeria meanwhile, the militant opposition continues to express its displeasure with the West by threatening death to any foreigner who dares enter their country. And I don't know about you, but in the wake of recent American bombings I wouldn't particularly care to take a holiday in Afgh- anistan or Sudan either.

If tourists become the proxy armies against which the disaffected fight their wars, tourism may soon be a luxury no-one can afford. Places like Ko Samui in Thailand, Goa in India, Cancun in Mexico - city-sized resorts which have developed on the back of international tourism - could be reduced to a shutter-banging-in-the-wind state of desolation. Anthropologists from the remote future will pick over their ruins in astonishment.

British tourists will no doubt continue to visit Europe and North America (assuming that world airlines are not entirely grounded). But nuclear India? North Africa embroiled in holy war? Russia, China and Indonesia in the throes of economic catastrophe? Will these be pleasant, relaxing or attractive places to visit? For the intrepid no doubt they will soon acquire the old allure of the "undiscovered" (much like today's Iran, for example, which provides such a superior touristic experience to the Iran of 20 years ago), but otherwise they may simply disappear from the list of feasible places to go for a holiday.

It is not impossible to imagine the whole apparatus of exotic travel - resorts, hotels, airports and tour-reps - following those other 20th century fads (colonialism, fascism etc) into the grave. And then the world economy really will be in a mess.