Brant Coopersmith, a fixture of Washington's civic life for 25 years, is no off-the-wall experimentalist. He is chairman of the D.C. Lottery Board, a longtime activist with the American Jewish Committee, a promoter of interracial understanding, and on virtually everybody's list of good guys.

This pillar of the community wants to legalize narcotics, not because he thinks the drugs are harmless but because he believes the futile efforts to ban them are far more harmful to the whole society.

He reads the newspaper accounts: worldwide drug abuse and related crime at unprecedented levels, the minister of justice of Colombia assassinated, a U.S Drug Enforcement Agency official kidnaped in Mexico, reports that DEA chief Francis M. Mullen may have a $350,000 price on his head. And he looks at himself and his friends, "imprisoned," as he puts it, in their homes out of fear of street crime.

He looks, and his conclusion is that the only way out of the mess we are in is to legalize narcotics. Not just marijuana, but cocaine, heroin, the works, subject only to the normal governmental regulations for ordinary drugs, perhaps with an age restriction on sales.

Coopersmith acknowledges that legalizing of dangerous narcotics will almost inevitably lead some previously reluctant idiots to experiment, and he thinks the lower prices that result from legalization might have some of the weaker ones among us nodding off in unproductive stupor. On the other hand, he believes if we used part of the savings that legalization would produce (including the cost of thousands of new prison cells) for a first-rate drug-education program, we might even reduce the amount of drug abuse.

"But that's just a hope," he said. "The certainty is that the laws designed to protect the weakest people from their own folly are making prisoners of the rest of us. Crime in the street is mostly drug related, and fear of that crime has imprisoned the nice people. The rest of the population, especially the senior citizens, are at the mercy of the drug abusers."

Coopersmith, realist that he is, won't be surprised if Congress rejects his advice, but he is convinced it would be a hideous mistake to do so. Lawmakers, like law enforcers, are still attracted by the seductive notion that if we put our minds to it, we can stop the traffic in dangerous drugs. They used to think it could be done domestically. The current prevailing myth is that we can do it if we can secure international cooperation.

It may be that we can't do it at all. Just last month, the International Narcotics Control Board, an agency of the United Nations, painted this grim picture: "Illicit (drug) production, trafficking and abuse" is affecting "an unprecedented number of countries and human beings. . . . The problem has become so pervasive that . . . even the security of some states is threatened."

The reason, of course, is that enormous amounts of money can be made from trafficking in illegal drugs, money that not only provides the underworld with the cash for operations that have no direct connection with narcotics but also provides the means of corrupting politicians, bankers, law-enforcement agencies and even governments. As Coopersmith points out, both the money and the corruption exist almost solely because the drugs are illegal. "Without the illegality, a heroin fix would cost little more than a cigarette," he says.

You get a sense of the vast amounts of money involved when you read that traffickers can afford to ditch expensive boats and planes after they deliver a single cargo, that they find it economic to build landing strips for one-time use, even for marijuana. "Enough money can corrupt virtually anybody," Coopersmith says.

Coopersmith recognizes that drug abuse also is corrupting and would be even if the drugs were legal. But that's a problem for those foolish enough or weak enough to indulge. The illegality makes it a problem for the rest of us, he says, and that one could be fixed with the stroke of a pen.