CAPE TOWN, SOUTH AFRICA -- South Africa's minister for law and order, Adriaan Vlok, says that while the 16-month-long state of emergency has succeeded in cooling the country's revolutionary climate, it will have to remain in force for the foreseeable future.

Vlok said that before seriously considering lifting the emergency, the government will have to finish addressing blacks' demands for upgrading their living conditions and make significant progress in power-sharing negotiations with the black majority.

"We would like to lift the emergency, but it would be irresponsible if we don't once again have stable communities and if we don't accomplish our three main goals," Vlok said in an interview this week with Katharine Graham, chairman of the board of The Washington Post Co.

Those goals, Vlok said, are: imposing security police actions to bring short-term stability to black townships; upgrading living conditions for blacks and finding a political solution that will give South Africa's 23 million blacks a role in governing the country.

He acknowledged that achieving these goals would take time, although he offered no timetable.

Vlok said the government would pay particular attention to further dismantling the "alternative governmental structures" that radical blacks established in the townships as unrest peaked in the two years before the emergency was imposed on June 12, 1986.

He said the alternative structures -- including "people's courts," protest education, street committees and parapolice groups formed by young "comrades" -- had been weakened by the emergency, but not eliminated.

These "governments within the government" pose the most serious threat to law and order in South Africa and could become the object of official banning, Vlok said.

At present, under South Africa's sweeping Internal Security Act, the government can detain without charges the leaders of the alternative structures, but cannot officially ban the existence of the parallel institutions.

"They {the radicals} tried to create an alternative system for the police and the courts. They instructed people not to report crimes to the police, but to report them only to the 'comrades,' " Vlok said.

"This is why we say a revolutionary climate still exists. This we cannot allow," he said, adding that only the emergency stands in the way of a resurgence of the alternative structures.

Vlok said an earlier state of emergency, imposed in selected areas of South Africa between July 1985 and March 1986, had been lifted with the expectation that a return to normal conditions would encourage moderate black leaders to negotiate peaceful change. But he added, "People did not come forward, and the unrest got worse. We cannot make the same mistake."

Vlok said the government was watching a treason trial in Johannesburg in which several residents of the black township of Alexandra are accused of having set up alternative government structures, allegedly to undermine the elected township council and foment unrest.

Calling the outcome potentially a "landmark verdict," Vlok said, "If they are found guilty, it will be easier for us to arrest these kind of people."

Vlok also said the government was paying close attention to the National Education Crisis Committee, which last year was active in establishing "people's education" in the townships as an alternative to the state education system.

"If you look at the type of education they want for South Africa, this is the kind of revolutionary thing they are trying to spread," Vlok said. He added that the emergency helped stem the spread of such activities and could not be lifted until that threat was eliminated.

"We don't have any fight with black people who want to change their education system, but they must do it in an orderly way with the government. You can't allow revolutionary ideology and communist ideology to be taught in the schools," Vlok said.

Vlok acknowledged that the committee had been instrumental last year in ending a year-long school boycott by blacks but said the group's renewed efforts to establish people's education jeopardized its existence.

The pacification of black townships by upgrading services and facilities, coupled with better education and more job opportunities, would have to be developed more before a return to normal law can be considered, Vlok said.

"It depends how long this will take before we can lift the emergency," he said.