An off-duty security guard is standing on the street in midtown Manhattan with his friend, trying to hail a cab, when he’s accosted by three men. A minute later, he’s been fatally shot in the chest.

What looked to witnesses like a senseless act of violence was actually an undercover police operation. The apparent victim, an unarmed Brooklyn man named Patrick Dorismond, was the target of a drug sting.

A plainclothes detective asked Dorismond and his friend if they knew where he could buy marijuana. Dorismond responded angrily, and a fight ensued. Two other detectives came to their colleague’s aid, and one of them drew the gun that killed Dorismond.

Police and civilian accounts of the incident differ on several points: who threw the first punch, whether the detectives identified themselves as police officers, how the gun went off. But there is one important fact about this case that does not hinge on such details: Patrick Dorismond was a casualty of the war on drugs.

Dorismond is dead because the police were trying to lure people, apparently at random, into selling marijuana. He is dead because the government is determined to disrupt this activity, even though no one involved in it is complaining.

In short, Dorismond is dead because politicians like New York City Mayor Rudolph Giuliani can’t stand the thought that someone might alter his consciousness with a politically incorrect substance.

Don’t expect Hillary Clinton, Giuliani’s opponent in this year’s New York Senate race, to raise this point. Although she has criticized Giuliani for dredging up Dorismond’s modest criminal record, she is not likely to note that Dorismond would be alive if the government were not so determined to police our bloodstreams.

After all, drug arrests and drug control spending have risen to record levels under her husband’s administration, without a peep of protest from her. If she is troubled by the fact that Dorismond was killed in an effort to keep people from doing what President Clinton joked about on MTV, she’s not letting on.

A week after Dorismond’s death, the president’s drug czar, Barry McCaffrey, announced that "we are winning" the war on drugs. Yet the evidence he cited in his annual report to Congress contradicted that claim.

Casual cocaine and marijuana use is down, but drug-related deaths are up. McCaffrey bragged that Peru and Bolivia "have reduced coca cultivation by 66 percent and 55 percent, respectively," even while conceding "skyrocketing drug production in Colombia."

Cocaine and heroin prices are about as low as they’ve ever been, government tests find "unprecedented retail purity" for heroin, and record numbers of teenagers say drugs are readily available. These are not harbingers of victory.

The drug czar, of course, has to walk a delicate line. To maximize anti-drug spending, he needs to claim enough success to suggest that the current approach is working, but not so much that legislators get complacent.

He also needs to scare people about what could happen if the anti-drug budget is cut. McCaffrey warned Congress, for instance, that methamphetamine "remains one of the most dangerous substances America has ever confronted" and has "serious potential nationally to become the next ’crack’ cocaine epidemic."

A few years ago, the president was saying that methamphetamine could become "the crack of the ’90s." I guess they haven’t given up hope.

As evidence of the administration’s success in preventing this epidemic that is always on the verge of breaking out, McCaffrey noted that "methamphetamine seizures are dramatically up." But increased seizures are a sign of increased supply, not a sign of effective drug control.

At the local level, claims of victory are similarly suspect. New York’s crackdown on street dealers, which relies heavily on the sort of sting in which Patrick Dorismond died, was supposed to reduce homicides. It hasn’t.

The police are not even claiming that the operation has reduced drug consumption. Instead, they say it has driven drug sales indoors.

If that’s the goal, repealing prohibition would be a more effective approach. Not incidentally, it would also alleviate the disastrous side effects of the war on drugs, including black-market violence, official corruption, invasions of privacy, disrespect for the law, and the squandering of criminal justice resources.

After you consider the broader context of Patrick Dorismond’s fatal encounter with the police, it seems that the bystanders who witnessed the shooting were right in their initial impression: It was a senseless act of violence.