The ban, which makes it illegal for anyone to import, stock or sell tobacco products, became law on National Day, December 17th, last year, winning worldwide plaudits for a government that likes to say it puts the "Gross National Happiness" of its people ahead of indicators, such as Gross National Product, long held dear in the developed world.
 
In a nation given to such eccentricities, it should be hardly surprising that the ban is being enforced with appeals to the conscience, with smokers being told that smoking is not something good Buddhists do.

Anyone caught smoking in public is given a severe talking-to by police, told of the health implications and offered counselling to help them kick the habit - such is the nature of justice in the last Buddhist kingdom, perched precariously between India and China.

Smoking was hardly a big revenue earner for Bhutan's government before the ban: according to a report in the national newspaper, Kuensel, tobacco products imported from neighbouring India in 2003 were worth just 200,000 ngultrum (?3,529). Other imports, mostly from Hong Kong and Singapore, were worth 5 million ngultrum (?88,214) in 2002 and 2 million ngultrum (?35,289) in 2003.

It seems most of the cigarettes, pipe tobacco and snuff consumed in Bhutan before the ban was smuggled across the border from India. The arrest last month of two men found with contraband cigarettes hidden in the carcasses of pigs apparently destined for market suggests the practice is still widespread.

While the ban has been hailed as revolutionary, the country's minister for health Jigme Singay says it was the culmination of a popular movement that began in the central region of Bumtang more than a decade ago.

Bumtang, famous for high-quality dairy products and its Red Panda brand of wheat beer, is often compared to Switzerland for its rolling green hillsides dotted with cows. It banned smoking in public places in the early 1990s, setting a trend that rolled across the country; by the time the ban came into effect nationwide, 18 of Bhutan's 20 administrative districts had followed Bumtang's lead. "The pressure was from the community and the people themselves. It was not a top-down measure, though many people outside the country have the notion that the government introduced the ban suddenly," says Singay.

Smoking was already banned in government buildings and monasteries - which in many parts of Bhutan, where the monarch and the je kehnpo, or chief abbot, share equal status - are one and the same. Even King Jigme Singye Wangchuck has cut down, says Singay, though he is quick to add that the monarch, who is regarded almost as a god-like figure and is spoken of in hushed tones, has never been seen smoking in public.

Some of the king's relatives, however, appear to have no such qualms, puffing on cigarettes and cigars in the bars and restaurants of Thimphu and the nearby town of Paro, complaining loudly about the new law and the need to pay duty when they bring cigarettes back from abroad.

Singay is half-way through a five-year term as Bhutan's health minister. He sits in his expansive office in the ministry's new building on a hill above Thimphu wearing a traditional knee-length goh, a wrap-around garment that Bhutanese men must, by law, wear in public, along with a bright orange, raw silk scarf and ceremonial sword that signify his ministerial rank.

While he maintains that less than 5 per cent of Bhutan's population - which various estimates put at between 600,000 and two million - would have been habitual smokers, he concedes the habit was increasingly popular among young people who are more vulnerable to outside influences such as movies.

Not much seems to have changed, however, as in the handful of bars and dance halls in Thimphu and in rough-and-tumble Paro, there is little evidence that the ban has had an impact on the people chatting, drinking and smoking just as they had before its introduction.

"It was always like this, you just wouldn't know the difference," says one young man who has been trying to cut down his packet-a-day habit since the ban. Even in daylight, some adults will still light up, though some duck into alleys to do so.

The price of tobacco products has doubled, with a packet of 20 Wills, a popular Indian brand, now costing 60 ngultrum (?1.06). Anyone bringing in cigarettes for their own consumption is hit with customs and sales tax of 300 per cent.

The ban on tobacco seems to sit uneasily with a greater scourge on public health - the use of betel, a mildly narcotic nut, mostly imported from India, which is mixed with lime and other flavourings, and chewed by most of the adult population, as well as by many children. It rots the teeth, while staining them red, and produces huge quantities of saliva which is spat in crimson streams on to footpaths, streets, walls and, sometimes, into rubbish bins.

Chewing betel can cause mouth, throat and stomach cancer yet, unlike tobacco, it is regarded by Bhutanese as an "auspicious item" associated with Buddhist rituals, Singay explains, making it difficult for the authorities to use the tactics used against tobacco to reduce its use.

Appeals on the grounds of health are pointless, he said. "No-one will give up something because you tell them it is bad for their health, that is human nature. But if you tell them it is not compatible with their religion, they will take that seriously. Betel nut presents us with a problem."

One civil servant says the tobacco ban presented him with an opportunity to give up. "I wanted to stop before, and I think the ban just gave me the incentive I needed, but it's not easy," he says. "My wife is finding it doubly difficult, but I tell her this is the Buddhist way."