However, senior police officers admit that the public has to read between the lines. "If we seize more, then it simply means that more got through," says Roy Clark, co-ordinator of the South-East Regional Crime Squad, the biggest of England's five regional-level police organisations. "All the law enforcement agencies in the UK put together cannot beat the drug trade," he adds. The talk among law enforcers is of "providing value for money", where money is a finite resource. It is a language that acknowledges the mercantile nature of the drugs world. "The person who would understand the drugs trade best is not a criminologist or a sociologist, but an economist," Clark says. "The comparisons with the free market economy are frightening. If this were a legitimate trade, it would be looked upon as marvellous enterprise."
The different levels of drug trafficker, supplier and dealer are mirrored in the chain of enforcement and intelligence agencies pitted against them. At the top end is the internationally connected National Criminal Intelligence Service which gathers information to help HM Customs and Excise, together with the regional crime squads, tackle organised importers and exporters. Middle-tier suppliers are primarily the responsibility of force area drug squads. These proactive units are allowed to pay for information and buy drugs in order to catch suspects. Below them are the divisional teams, which take on local dealers. On the street, police are empowered by the Misuse of Drugs Act (1971) and the Police and Criminal Evidence Act (1984) to stop and search anyone they reasonably suspect to be in possession of controlled drugs. The government is also spending millions of pounds over the next three years on improving drugs education in schools and setting up nationwide, locally-based Drug Prevention Teams. Much of the effort that goes into reducing supply and demand is therefore invisible to the public eye.
THE CUSTOMS OFFICER
The line of text scrolling across Keith Bowen's computer screen relentlessly announces: "HM Customs and Excise, Combatting Drugs and Protecting Society at London (Heathrow), the World's Busiest Airport". Bowen, head of investigations, is discussing the morning's anti-smuggling work with Barry Gyseman, head of operations. It's 11am and, it being a week before Christmas, things are busy. The main event so far has been a "cold detection" by a packet examiner of a double-bottomed suitcase in transit from Panama to Brussels. Bowen has tipped off the Belgian gendarmes, who are following the courier into the country.
This is normal procedure. "The courier is a nothing person," Bowen explains. "We want to catch the organiser, who often doesn't touch the drugs." By this stage, there are already a number of "mules" in Heathrow custody: a "stuffer" (a woman with internal concealments of heroin), a man with a packet of heroin strapped round his stomach and two couriers just in from Kingston, Jamaica (via Miami) with bags of herbal cannabis suspended in bottles of honey. All these are classed as commercial, rather than personal use seizures (less than 2.5k of cannabis or 50g of a Class A drug). The last two were intelligence-led operations, the first an "intuitive" detection by a customs officer. Half of all detections are made on the spot.
Gyseman heads for Terminal 3, to see in some high-risk long-haul flights ("West Africa, the West Indies, Asia, South America, they're our bread and butter"). In the Anything to Declare channel, customs officer Kelvin Darby is using his intuitive "sixth sense" on a man walking through some 30 minutes after his plane landed from Tangiers. He calls him over. The man explains that he has lost his suitcase. "What do you do?" Darby asks, fingers feeling round the hand-luggage. "I'm a cab-driver," says the man. "Good time of year to go away, was it, in your business?" "That's why I've come back - I'll work from now on." "Must be a fair amount of money going at Christmas." "It was the only time I could get away." "Did you pack the bags yourself?" "Yes." "No one give you any thing to pack?" "No." "These are?" (opening the bag). "Just cakes."
After the cakes have been passed through a scanner and four M&S suits admired ("Mmm, expensive"), the man is allowed to go. Darby explains the process involved: "I established his position in society, whether he could afford to travel and the kind of work he did. If someone has a pounds 500 suit and says they are unemployed, that tends to stick out. In your own mind, you try to establish what is normal." A particular profile, even that of a white western female, can set alarm bells ringing if the flight they are on is deemed high-risk. "Someone will break the plane of your consciousness and you will step back a for a minute," Gyseman suggests.
As he finishes work, hanging around just to see in a 3pm flight from Pakistan ("Everyone on that will be suspect"), Gyseman muses on life on the customs bench: "It is a closed, claustrophobic environment - you are being paid to be suspicious of everyone passing in front of you." The job has its rewards, though. "When you take out heroin, you are protecting society. That feels good."
THE DRUG SQUAD
"Early? You call this early?" chime Stef and Sharon, plain clothes detective constables from 4 Area Drug Squad, as we drive through the 7am darkness to an address in south-east London. "You always have to be available," explains Stef. "Your social life suffers and if you're a woman, you can't have kids, but that's the price you pay for an interesting job." Today, the work is routine - a raid on the premises of man whom a "reliable source" has told the squad is drugs running. No battering down of doors, just a brandishing of a warrant. They pull up in a suburban street and settle back for the predicted emergence of the man at 8.30am, keeping in radio contact with four colleagues parked nearby.
They discuss careers, the Queen's corgis, gypsies in Orpington, tales of being mistakenly chatted up in night clubs by dealers ("He was stupid enough to give me a card with his number - we nicked him the next week," says Sharon). It gets to 8.30am and nothing happens. Over an hour later, the "target" stirs and the team moves in. There is a tense start. The man thinks the two arresting officers are aggrieved relatives, who've come round to sort him out. "One of them reckons he's a face in Battersea, but he's third rate," he jokes as the officers relax into the search. A baseball bat stands propped by the front door. The sniffer dog sniffs, drawers are opened, mattresses turned, and the team keep up a running banter. After half an hour, they have found nothing; the officers are on the point of leaving (and de-arresting) when the suspect's mother turns up. There is an awkward silence. "You're not involved in anything like that, are you?" she asks. " 'Course not, Old Bill just shown that, haven't they?" he replies.
"You could say we wasted out time," says the squad head DI Peter Spindler later, "but you never know until you try." The 17-strong squad has to be highly selective about whom it targets, because there are only resources to deal with a fraction of the dealers in the Metropolitan Police sector (roughly a quarter of London). Both Stef and Sharon are aware of the limited impact of their work. "I don't think we really touch it," Stef says. "You put someone in prison, there'll always someone who'll come out to take their place."
THE DRUGS EDUCATION OFFICER
PC Dick Westland fixes the class of 13-year-old girls from Norbury Manor School with a time-is-of-the-essence look: "You need to have information about drugs, and you will need to have opinions, because you will need to make decisions. I'm not here to say 'Don't take it'," he continues. "Don't tell me who your dealers are. I don't want to know." A mass of bright red jumpers convulses with laughter. PC Westland is undeterred (he has given a variant on this talk hundreds of times). His colleagues on the Youth and Schools Unit at Croydon Police Station have come across drug addicts as young as nine. He is confident that some of the pupils in front of him have already been exposed to drug-taking.
"How many have seen an illegal substance?" he asks. Six hands go up: "What have you seen?" he asks one. "Weed," says a blond-haired girl. "What's that?" She pauses. "Grass." "Why did you whisper 'spliff' into her ear?" he asks her neighbour, pointedly. "What do you do with a spliff?" "They smoke it, roll it up in something," she trails off, blushing. Westland fills her in on reefers and Rizlas. What else? "Cocaine," says another, "I've seen a friend take it and he's totally out of it."
There then follows, interspersed with giggling, a slide show, taking the class from solvent abuse to opiate production. They role-play being offered a spliff at a party. Although he repeatedly offers up information as neutral ("My advice is don't take it, but, as I say, it's your decision"), his talk is peppered with horror-stories: the girl who collapsed after taking speed to see her through GCSE revision, the man who continued to see the colour red as yellow after taking LSD. The pupils' response ranges from the cynical (about Leah Betts: "It was her fault, not the dealer's - she took it.") to the highly uninformed (about LSD: "If you put it in your mouth, do you see Donald Duck?") "That's the end of the shock tactics, because they don't work," Westland says suddenly, after showing them a heroin user's gangrenous leg. "Within half an hour you'll all be laughing about it."
"You can't tell a young person not to do something because they will do it," explains the head of the unit, Sergeant Ian Blunsom. His team is at the forefront of preventative drugs education, bringing it into classrooms from the age of nine. "There is a drugs problem among the young, and you can think, 'Why are we bothering?'. If that happens you might as well pack it in. But you have to remember that they're not all jacking up behind the bike shed."
"Current strategy could be described as keeping a lid on things, while the social programmes take effect," says Roy Clark.
The national police spokesman on drugs, Chief Constable Keith Hellawell, is confident that the new emphasis on education will pay off, conceding that police success is dependent on wider social factors. The official police line on cannabis implicitly reflects this: both backing the Government against legalisation, but also regularly using cautioning to deal with the massive number of possession cases. "Cannabis is now as available as lemonade," Clark concedes.
Privately, officers have divergent views on the social roots of drug abuse. For example, one attributed the involvement of unemployed youths in drug dealing to a basic desire to improve their lot.
Another was perplexed by the current focus on ecstasy: "There is concern because E has got into the middle-classes; they're not bothered if people in Brixton take crack or heroin as long as it doesn't affect them."
But the niceties of such responses inevitably run up against the everyday demands of the job. As one officer put it: "I'm a human being, and I can think for myself, but at the end of the day, the law's the law."