Like some absolutist travel agent who won't let his customers read the Rough Guide to where they are going, Angus MacQueen likes to hurl viewers mapless into his documentaries. Gulag, his masterpiece on Stalin's Terror, and The Last Peasants, about illegal immigration from eastern Europe, were not, in this sense (among others), easy viewing. Nor is his latest, Cocaine (16, 20 and 23 January), a series of films relying on a minimum of commentary and a maximum of viewer concentration. However, the rewards of having to work to make sense of the images and characters that bombard us are great. We leave each documentary with the impression that we have made MacQueen's discoveries ourselves.
In three hour-long films, Cocaine provides a supply-side tour of the drug trade, never once bothering us with clips of snorting westerners or Daniella Westbrook's ex-septum. The first part, located in the coca fields of Peru, shows us a peasant farmer, gun in jeans, brewing up the stuff in an alfresco laboratory whose most expensive piece of equipment is a microwave. The next takes us to Rio in Brazil, where distribution of the processed drug is controlled by the gangs who run sections of the city. The third deals with the Sisyphean efforts of the Colombian government to eliminate the trade. And so we work out the logic of the films: production, distribution, suppression - although there is another schema at work, a widening progression from the corruption of a community, to the destruction of a town, to the death of a state.
The corrupted community is based in the Peruvian town of Monzon, a 21st- century Deadwood where everyone carries a gun and there's no rule of law, although the Peruvian army hoists the national flag every Sunday for the look of the thing. Coca has been grown for centuries in the Andes, where the locals chew it to relieve their toothache. Since cocaine's elevation to top drug, however, farmers have found themselves with a cash crop - although at £600 a kilo (as against the £35,000 a kilo for which it sells in Europe), it is not making them rich.
What livelihoods they do enjoy are threatened by the government's war on drugs: the fungus sprayed on the crops has caused some to give up growing it, but the alternative crops fail to find a market. Meanwhile, the police run wild; the almost extinct Shining Path guerrillas, presenting themselves as the farmers' saviours, are on the way back; and the next generation is looking for other ways to survive. The saddest sequences of the film show the academically minded daughter of a farming family attempt to pay her college fees by entering a beauty contest she is ill-equipped to win. The film leaves her taking a job as a dancer at one of Monzon's seedier night spots. Prostitution beckons. Her clients will surely be the cocaine profiteers.
The second film plonks us in the favela of Santa Marta, which we work out is Rio de Janeiro's slum quarter, where youths wearing balaclavas are parcelling the coke into ten-gram parcels. One of them is soon boasting to a friend about getting a girlfriend pregnant and packing her off to her mother's. His pal asks nervously if he is getting on well with everyone in the gang. The correct answer would be: not as well as he needs to. Leo is in debt to it because a friend has run off with his money. In another part of the city, his aunt, who adopted him after his gangster father was killed, weeps into her cooking. An end caption tells us that, two months after the filming, Leo was murdered by the gang and his body cut up.
There should be more hope springing eternal in film three, An Honest Citizen. The citizen is Maria Cristina Chirolla, an attractive, competent lawyer in her middle years who leads Colombia's anti-money-laundering agency. In a country where everyone leans towards corruption, she looks like the exception to prove the rule. But the more the film goes on, the more hopeless her task seems. A raid on a drug baron is thwarted when he is tipped off. Then information comes that there was a plot to assassinate her during the raid. In a conversation between her and the country's vice-president, she tells him that she is getting no international-level intelligence. Vice-President Francisco Santos Calderon says she should talk to the Financial Intelligence Unit. "But," she says, "it's a sham."
It is gripping television, but the drawback of MacQueen's minimalist approach becomes evident, for there is too much relevant Colombian history - the war between the right-wing paramilitaries and the communist Farc, the exploits of the 1980s drug barons such as Pablo Escobar, the years of kidnappings - for the untutored traveller to grasp the issues.
A bonus of MacQueen's technique is that it encourages us to make up our own minds. In plugging the programmes, he has been doing the rounds saying he has been persuaded of the need to legalise cocaine. I happen to agree with him, but the conclusion is not inevitable. In programme three, we get sung a calypso - the only incidental music in the films. It goes:
We didn't create the problem
Others created it for us
We simply grow coca
It's abroad they use it
The gringos stuff their brains with it.
Any brain-stuffing gringo with a conscience who sees these films will now stop.
Andrew Billen is a staff writer on the Times