It was my own experience as a policeman trying to enforce the laws against drugs that led me to change my attitude about drug-control policy. The analogy to the Vietnam War is fitting. I was a willing foot soldier at the start of the modern drug war, pounding a beat in Harlem. During the early 1960s, as heroin use spread, we made many arrests, but it did not take long before cops realized that arrests did not lessen drug selling or drug use.

I came to realize just how ineffective we were in deterring drug use one day when my partner and I arrested an addict for possession of a hypodermic needle and heroin. Our prisoner had already shot up, but the heroin charge we were prepared to level at him was based on the tiny residue in the bottle cap used to heat the fix. It was petty, but then -- and now -- such arrests are valued because they can be used to claim success, like the body counts during the Vietnam War.

In this case the addict offered to ``give'' us a pusher in exchange for letting him go. He would lure the pusher into a hallway where we could then arrest him in the act of selling drugs. We trailed the addict along Lenox Avenue. To our surprise, he spoke to one man after another.

It suddenly struck me as humiliating, the whole scene. Here it was, broad daylight. We were brilliantly visible, in uniform, in a marked police car: and yet a few feet away, our quarry was attempting one drug transaction after another. The first two dealers weren't deterred by our presence -- they were simply sold out, and we could not arrest them without the goods. We finally arrested the third pusher, letting the first addict escape, as we had covenanted. The man we brought in was selling drugs only to support his own habit.

Another inherent difficulty in drug enforcement is that violators are engaging in consensual activity and seek privacy. Every day, millions of drug crimes similar to what took place in front of our police car occur without police knowledge. To enforce drug laws the police have to resort to undercover work, which is dangerous to them and also to innocent bystanders. Drug enforcement often involves questionable ethical behavior by the police, such as what we did in letting a guilty person go free because he enticed someone else into violating the law.