Ultimately, carefully planned and managed tourism will be the basis of development there. Government investment in basic transport infrastructure will have its positive and negative effects: it will promote the economic development of local people; but it will attract large numbers of visitors, who may damage its potential for sustainable development.

'The planet must bear in mind that the ecology of this region is the most fragile [in the world],' said Mr Paudyal. 'Potential benefits will accrue from protecting it. To destroy the environment would kill the goose that lays the golden eggs.'

Several steps must be taken to assure the sustainable development of the region in the interests of the people living on both sides of the Nepal-China border, he said.

First, protecting the world's most fragile ecosystem requires advance planning. Second, people will come to this region to experience its natural environment, not necessarily to enjoy luxury. So destroying the environment to build massive hotel projects and tourism facilities - as in the rest of China - would hamper the long-term, sustainable development of tourism.

Third, the capacity of indigenous people should be strengthened by developing local resources. The Himalayan region of Nepal and China possesses sites sacred to both Buddhism and Hinduism. That heritage provides cultural and religious attractions, but it must be developed sensitively. For example, thousands of pilgrims want to visit Tibet's Mount Kailash, which is sacred to Buddhists, Hindus, followers of Tibet's indigenous Bon religion and India's Jain faith.

But complicated travel procedures, physical dangers and low service standards discourage many. They could be encouraged to visit this spectacular, remote region if emergency medical care, for example, were provided along the route.

The first step is to develop infrastructure jointly, to help small groups travel for cultural and ecological tourism. The second is easing border-crossing restrictions through a joint co-ordinating body. A visionary plan for trans-Himalayan development and more China-Nepal dialogue are needed.

But co-operation is not always easy. The vital bus link between Katmandu and Lhasa is not functioning well as a joint enterprise, so private cars ply the route, instead. The Chinese claim there's not enough business to support the bus route; the Nepalese say Chinese red tape hobbles the business.

Communities on both sides of the border would benefit from expanded trade in cottage-industry products. While these small businesses may generate only a fraction of the gross domestic product, they employ people at the grass-roots level. In the 1960s they were the backbone of Nepal's economy, but are now in decline.

So development must be rethought, sensitised and localised to provide the most benefit to indigenous people. The governments of China and Nepal must work together to monitor the protection of the environment and the sensitivity of new infrastructure projects. Otherwise, after the trains start rolling into Lhasa, it may soon be too late.

Laurence Brahm is a political economist, author, filmmaker and founder of Shambhala Foundation