ONCE a state's legitimacy goes, even repressive force rarely stems the tide of change. Eastern Europe demonstrates this. Somewhat less dramatically, so does South Africa, where the legitimacy of white rule has been seriously undercut by two surprising events. First came a serious attack on the nation's 30-year-old system of separate black homelands. Second, a series of disclosures suggested that the security police have been systematically assassinating the government's opponents for at least a decade.
In 1959 South Africa created 10 artificial islands for different African groupings. At first called bantustans, now homelands, they were a response to worldwide calls for political participation by blacks. Africans could vote in their own areas, said Pretoria. By 1963, the Transkei, a Xhosa homeland, had been declared self-governing. In 1976, it became the first of four homelands to accept ``independence.''
Only South Africa recognized that independence, and South Africa continued to be the primary budgetary and developmental supporter of the Transkei, Bophuthatswana, Venda, and Ciskei.
Last month, Maj. Gen. Bantu Holomisa, military ruler of the Transkei, proposed rescinding ``independence.'' General Holomisa, who is close to the banned African National Congress (ANC), asserted that the process of gaining independence had been fraudulent.
Although Holomisa's lead will not immediately be followed by the wealthy chiefs who control the other ``independent'' homelands, his move was welcomed by Chief M. Gatsha Buthelezi, the head of KwaZulu, and Enos Mabuza, chief minister of KaNgwane.
Holomisa's pressure for reincorporation within South Africa is less immediately electrifying than sensational disclosures about the country's security forces. But both undermine the established order and the credibility of a state already shaken by change.
Police complicity in a string of 50 unexplained murders since the '70s has long been suspected. Deaths of blacks like Mathew Goniwe, a community activist, came on remote highways. Siphiwe Mthimkulu, a student leader, was poisoned. Ruth First, author and wife of Joe Slovo, an ANC militant, was blown up by a parcel bomb in Maputo. Jenny Schoon, wife of ANC operative Marius Schoon, was killed by a letter bomb. Several other whites, from political scientist Richard Turner in Durban in 1978 to professor David Webster in Johannesburg this year, were gunned down from speeding cars. All were opponents of minority white rule and apartheid.
No one has ever successfully been prosecuted for the murders. Police investigations always came to naught, although in some cases the White Wolves, a shadowy right-wing organization, claimed responsibility. Finally, a few months ago, Butana Almond Nofomela, an imprisoned black policeman on death row for his part in a nonrelated escapade, accused whites in the security police of running death squads.
Mr. Nofomela's accusations led a struggling opposition Afrikaans weekly to investigate further. Vrye Weekblad interviewed Dirk Coetzee, a security police captain and Nofomela's former chief. Captain Coetzee described how he had actively planned and participated in terrorist attacks and murders.
According to subsequent allegations, Gen. Lothar Neethling, a policy forensic chemist, prepared poisons for some of the persons who were killed, and Gen. Johann Coetzee (no relation to the first Coetzee), former commissioner of police, personally authorized killings.
President Frederik W. De Klerk has ordered an investigation, but has refused demands for an independent judicial inquiry. It is already evident, however, that a trusted arm of the state had at least modest involvement in a string of mafia-type murders. Police in places like Paraguay and Uganda have perpetrated similar outrages. But white South Africa likes to compare itself to Christian-based Western democracies. It has always claimed to abide by civilized norms, and to fear black rule primarily because blacks would breach the rule of law.
President De Klerk can blame police excesses on the misrule of his already reviled predecessor, Pieter W. Botha. But he was himself a member of the Cabinet during Botha's rule, as well as head of the ruling National Party in the Transvaal, where most of the murders took place. He and his colleagues can hardly remain unscathed.
White South Africa was already moving hesitantly toward some kind of accommodation with blacks. Now, thanks to the rising disaffection in the homelands and the destruction of cherished myths about the police, a genuine sharing of power may come sooner than anyone six months ago could have imagined.