SOUTH AFRICA'S government is tightening up on the news. In the last few days, it has invoked the apartheid system's draconian internal security legislation to charge the white editor of the Cape Times, Tony Heard, for publishing what was the first substantial interview in the South African press in 25 years with a black guerrilla leader. Oliver Tambo of the African National Congress had urged the government to create a climate for talks. The newspaper deemed publication "a contribution to peaceful solutions in South Africa in a matter of overwhelming public importance." The government saw an intrusion upon its chosen course of toughing it out. Others will see an insistence on flying blind.

Other new curbs decreed by the government will substantially thin the news flowing to the international public as well as to South Africans. Television, radio and photographic correspondents are henceforth barred from areas of unrest. Newspaper and magazine journalists can enter those areas, but only with police permission.

This is not the first place in which officials have been angered by the media, especially by television, with its distinctive ability to touch the emotions of a broad public. What is distinctive here is the evident aim of keeping pictures of discontent from the foreign public, mostly, we presume, from the American public. Pretoria has been stunned to find public and even official support fading in the United States, the one country it previously regarded as reliable.

The government claims television coverage of violence actually incites disturbances -- as though apartheid did not light its own fires. It is more plausible that the government acted because of the "unprecedented intensity of interest" in South Africa that a Cape Times journalist found in the United States during a recent visit. Noting that Bishop Desmond Tutu's "impact as a communicator was electrifying" to the American public, Gerald Shaw wrote, fairly: "But it was the police whippings that really did it -- the sight, night after night on television, of South African policemen whipping people in the streets of South Africa, whipping them as they ran, whipping them on the ground, dragging them along with one hand and whipping away furiously with the other."

To this spectacle, two broad responses were possible. One, that favored by Gerald Shaw and the Cape Times among others in South Africa, was political dialogue. The other, that of the government, was censorship. The reprisals against journalists, like the uproar in the townships, is likely to strengthen the West in its view that apartheid is destroying South Africa.