is the thing we can do to talk to people and tell them there is a way to stop."

Statistics associated with drug abuse are not easy to parse. Laws, approaches, and customs vary widely among countries, and they change over the years. In the nineteen-eighties, the prevailing trend in most of the world was toward harsher treatment of even casual users. Today, policy officials in many countries are trying to change that pattern, but there are many goals in the war on drugs, and it is hard to choose the most meaningful among them. Is drug use increasing? Has it become socially and economically ruinous? What drugs are being used and by whom? How much violence is associated with drug addiction? How old are those with the biggest problem and why do they have that problem? Poverty is often the answer to the last question, and in 1999, before Portugal introduced the new regimen, the country had a high level of poverty compared with other European nations, many heroin addicts, and a serious problem with H.I.V. Thirty-seven per cent of injecting drug users were receiving methadone to manage their addiction; ten years later, that figure was sixty-seven per cent. The number of people convicted of drug offenses fell from forty-four per cent of the prison population, in 2000, to twenty-one per cent, in 2005; the percentage of people using heroin in prison also fell sharply.

"I used to be the biggest believer in locking up the bad guys," João Figueira, the chief inspector of the Judicial Police crime squad and its drug division in Lisbon, said. He told me that he was unhappy when the law was introduced, and he struggled with it morally. Within a year, he had changed his mind. "In the last years before the law, consumers were arrested by police," he continued. "They were fingerprinted and made statements and took mug photos and were presented to court. And always, always, always released. It was a waste of everyone's time. It didn't stop drug use or slow down the dealers. So the idea that somehow people are getting away with what they did not get away with before is silly."

Elisabete Moutinho, a clinical psychologist, who works for one of the drug outreach programs funded by the Ministry of Health, stood on a cobblestone plateau above the slope that leads to what was once the center of Lisbon's Casal Ventoso neighborhood. She looked across a nearby highway at a housing development of the type that often seems to rise along the ring roads that circle the world's capitals. It was utilitarian, and utterly lacking in charm. "That must be a dull place to live," I said. She smiled and replied, "There are worse things than dull. In this area, dull is an improvement." Twenty-five years ago, Casal Ventoso was essentially a giant shooting gallery, and, every day, thousands of people would line up to buy heroin, then they would fade into the dense warren of homes and kiosks that covered a series of connected hills. Walking through the squalid neighborhood meant weaving around piles of used, often bloody needles and, on occasion, stepping over a dead body. Casal Ventoso was a daily catalogue of human misery. In 1998, the government brought in a fleet of bulldozers and razed the neighborhood.

Moutinho, who is thirty, is a charismatic and idealistic woman with a demeanor that invites people to tell her their problems. "We are not here to judge or scold," she said. "This is purely a public-health initiative. We want these people in the system, unafraid, able to come to us if they are in need. And in turn we test them for diseases, treat them when they are sick. This is a better outcome for them than taking them to the hospital or the morgue. And it is a better outcome for the people of this country."

She and her team had arrived in a station wagon filled with drug paraphernalia: tinfoil, for people who smoke heroin rather than shoot it (which is often the only way for longtime addicts to get their fix, since years