HAVING DECLARED that "drug dealers are not going to be on the streets while I'm mayor," the District's chief executive, Anthony Williams, has now unveiled his plan to close down open-air drug markets and reduce drug-related crime in the city. The plan released yesterday contains something old, something new, something borrowed and something straight out of the chief of police's playbook. At issue is whether any of it will work.

The old items -- community policing and targeted enforcement focused on repeat offenders -- were around during the various Barry administrations. Open-air mini-stations (highly visible outdoor picnic-table-and-chair sets complete with a cop) are a new initiative of Chief Ramsey that might scare drug dealers from that location. The plan's prevention proposals for the public schools and alternative after-school programs are ideas as old as the Sharon Pratt Kelly administration.

The mayor's drug-fighting goals are unassailable. He aims to cut drug-related crime and violence, educate kids to avoid illegal drugs and reduce the public health and social costs of drug use. Laudable as they are, their achievement is difficult to measure.

Of course, the public will know if the mayor has successfully closed down open-air drug markets when drug dealers are no longer operating openly on the streets. The direction of violent crime statistics will also tell whether the mayor's attack on the supply side of the drug problem is actually paying off. Likewise, if, say, a year from now drug users and drug-dependent offenders are receiving treatment in greater numbers than currently, mayoral efforts on the "demand" side of the drug equation may be bearing fruit.

The mayor might do well to consult closely with the council on his drug initiative, especially David Catania (R-At Large), who is sponsoring the Choice in Drug Treatment Act, which has an innovative addiction recovery fund. That measure would restructure the city's Addiction Prevention Recovery Administration so that expert nonprofit providers can aggressively extend detoxification and treatment to addicts and alcoholics -- the source of many foster care and criminal justice problems.

Working together, the executive and legislative branches may help ease the city's drug problem. Working at cross purposes will only enable drug dealers to continue the banner business they now enjoy.