It was hard to know whether Dan Bent, U.S. attorney for Hawaii, had come up with an interesting new insight or had merely reverted to an old and largely discredited view.

Bent, in town for a meeting of federal prosecutors, was holding forth on the link between drug abuse and crime. No, not the link you're thinking of. Sociologists tend to look at the relationship between drugs and crime in one of three ways, he said.

There is the cross-the-line notion that when a person uses illegal drugs -- and thereby crosses the line from legitimate to illegitimate behavior -- it becomes easier for him to break other laws.

There is the association theory that drug use, even on a social basis, entails association with lawbreakers and therefore makes it easier for the drug user to slip into other viola-tions.

And there is the economic-need idea that drug abusers break non-drug laws in order to get the money to support their craving for narcotics.

"All these theories are valid up to a point," said Bent, "but even those who have come up with the theories recognize that they don't explain everything. For example, economic need works well to explain crimes associated with heroin abuse, but not for 'crack.' Economic need doesn't explain Elizabeth Steinberg {the 6-year-old New Yorker allegedly beaten to death by her drug-abusing adoptive parents}."

So what crime/drug abuse connection is Bent talking about?

"There's an organ in the body that controls behavior: the brain. Introduce chemicals into that organ and, over time, you end up with an organ that is less capable of doing what it is supposed to do. With a large population of drug users, you are more likely to have people engaging in behaviors that they wouldn't otherwise engage in: from absenteeism to the murder of a 6-year-old."

Is this a budding breakthrough or only a revival of the notion of the drug-crazed dope fiend?

Even if it is the former, Bent isn't sure where it leads in dealing with the drug problem. He knows it means that "prosecution isn't the total answer" -- but beyond that?

"I don't know," he admitted. "I used to think educating people about the health effects of drugs was the way to go. I know now, as a result of my growing understanding of the brain, that the effect of narcotics is to 'hot-wire' the limbic center (the pleasure center of the brain). Once you've hot-wired the limbic center, then the logic part of the brain -- designed to serve the pleasure center -- won't be strong enough to exert control."

What is he talking about?

"Think of people who are cigarette smokers," he said. "They may know very well the long-term effects of cigarette smoking and still go right on smoking. The limbic system is appealed to by nicotine, and the logic part, which knows better, isn't able to overcome it."

Would it make sense, as many have advocated, to legalize narcotics, thereby taking the immense profits out of drug trafficking?

It would not, said Bent. You can't legalize narcotics for 12- and 13-year-olds, so you necessarily would have an illegal -- and therefore profitable -- market. Besides, he said, drug traffickers don't go around creating drug abusers in order to reap profits. "The major marketing mechanism is the intense pleasure that people get, plus availability. What profession leads the pack in drug abuse? Physicians. Second is nurses, and third is pharmacists. The key is availability.

"What happens if you turn to decriminalization and halt the efforts at interdiction? You increase the availability -- just as happened with alcohol. We don't need another alcohol in our society. Already Americans, 5 percent of the world's population, are consuming 60 percent of the world's illegal drugs."

So what do we do?

"I go back to what I was saying," Bent responded. "We need to pit limbic system against limbic system. Drugs stimulate the brain's pleasure center, but so does the approval of people we care about. We need to cultivate the disapproval of people who are important to drug abusers' ego survival: spouses, family, professional colleagues. We have to break down the notion that 'recreational' drug abuse among the professional classes is sophisticated and chic. We have to make clear the connection between drug abuse among the rich and crime in our streets and help non-drug users see that it is in their survival interest to do something about drug use in their community."

Isn't that a thin defense against a business that produces such enormous profits?

Bent doesn't think so. "It's working with cigarettes," he said. "We knew for a long time that cigarettes were bad for smokers. But nothing really changed until the surgeon general and the National Academy of Sciences came out with reports documenting that nonsmokers are affected by passive smoke. That's what produced the social sanctions against smoking, and after that the rules of the work place changed, and smoking started to decrease."