Supposed reasons for the shortage are legion and colourful. One is that a senior bent Dutch cop has been fired. "He is supposed to have been responsible for letting through some 400 tons a year," says Atha. Another is that big dealers are working as a cartel and stockpiling hashish in order to push up prices, which have been stable for about eight years at around pounds 25 to pounds 30 a quarter ounce.
Changing patterns of smuggling may have something to do with it. "The emphasis is shifting from large boatfuls to smaller quantities being smuggled more frequently," says Russell Cronin, spokesman for the Legalise Cannabis Campaign. There is also the steady shift of smuggling gangs from bulky dope consignments to more easily-hidden Class A drugs.
But most agree that the likeliest reason lies in Morocco, the biggest importer of hashish to the UK, which is reported to have clamped down on its producers. Some think this is due to an aid deal with the US; or that it is part of a general increase of despotism in the Maghreb; or that diplomatic difficulties with Spain mean that Iberian smuggling lines are down.
Whatever the reason for the dope deficit, pundits are concerned that dabblers may move to Class A drugs. Indeed, Schapiro cites the increasing practice of people mixing heroin in to their joints. "There is a pick- and- mix attitude within the drug culture," he says. A major downer, perhaps - but all is not lost. While hash stocks might be low, home-grown herbal marijuana is flooding on to the market. Once a last resort, home-grown is now a sophisticated player, grown in hi-tech "hydroponic" conditions, genetically-engineered, market-gardened and sold as named strains such as Skunk and Northern Lights.
"Home-grown has come out of the closet - and I do mean closet," says Cronin. "The implication of the word has changed. It used to mean lousy grass; now it equally means super-premium grass like Skunk. It is fresher and often stronger than imported weed." If the Moroccan does return, it may have to try a little harder. Indeed, in Amsterdam, the world's most demanding dope mega-mart, smokers actively choose hydroponic weed. Northern Lights, for instance, is a sativa-indica cross, sturdy and low- growing with massive THC (tetrahydrocannabinol - the active component)- laden heads. In other words, two tokes and you're caned.
But home-growing is a risky business in the UK. Anyone caught with plants, even a few small ones, will usually be charged with possession with intent to supply: an imprisonable offence. "It is bulky and neighbours often spot it or notice the smell," says Atha, who has closely observed the spiralling number of grow-your-own busts. "Some people do grow to sell, but not many - and it is not as lucrative as the police say it is. You can be sure that any 'street prices' quoted have been hiked up."
The march of home-grown continues unabated, and it features heavily in the dopers' "Olympics": the High Times Cannabis Cup in Amsterdam. Last year a winner was White Widow, a homegrown strain "so rich in THC that it glistens", according to one Dutch market player. And there is now a Dutch-grown hashish, Skuff, a resinous variety of Skunk. "It's comparable to the finest hand-made traditional hash," says Cronin. Perhaps they should sell it to the Moroccans.