THERE ARE TWO separate, fragmented groups of South Africans in Washington - the whites, mostly diplomats, and the blacks, mostly political refugees, now part of the professional and student communities.

The groups are small - their total number is probably under 200. South Africa's official policy of apartheid would keep them rigidly separated if they were at home. But even in Washington, "a wall exists," notes one black.

Usually nationals far from their own homes find some commonality of interest when they are living abroad, even if no such rapport would exist at home. Here in Washington, the South African Embassy is no haven for its black nationals. The wall between black South African and white is built on present pain and future uncertainty, the fear of a homeland shattered by civil war. Only occasionally do cracks appear in the partition - in th vacuous world of Washington cocktail parties, or the ubiquitous "seminars." But even in thos rarified arenas, black and white South Africans have been known to turn away from each other.

In their separateness, there are similarities: Each "community" is, in its way, conservative in outlook; the tumultuous events in their country are forcing them to look at each other - and themselves - in a different light. Conversations with the South Africans on both sides of the wall show individuals whose voices are muted by fears, smarting under attack, and groping with the historical fact that theirs are the faces that hammer into the world's consciousness their country's reputation as an unjust society.

It was on June 16, 1976, that the worst race riot in South Africa's history erupted in Soweto, and a week later, this was the fearful toll: at least 176 dead (all but two of them black) and 1,139 injured. Another 1,298 blacks were arrested, and property damage was estimated at $50 million.

Thousands of miles away, Sekhoane Job Rathebe, 29, sat in his apartment in Northwest Washington, rubbing his forehead, apprehensive and helpless. Where among the rubble of Soweto were his mother, his brother, his sister, his cousins?

"I knew my younger brother and sister had to be involved. But I also thought if anything happened my mother would send a telegram. But then I didn't know." His voice wound down in agonized pauses. It was September before he heard from his mother.

With wonderment and even a tinge of jealousy in his voice he said, "When I was a teen-ager we talked about the oppression, but we put a lot of time in sports, clothing, music, such that we could afford, because those were safety valves," said Rathebe. "As time goes on, one tends to accommodate oneself to South African laws, or to the lawlessness."

Rathebe didn't live in the township's typical overcrowded house. His high school education, finished in Swaziland, got him a clerk's job at 21 cents an hour. Eventually he was harassed for standing in the white line at the white coffee machine and he protested. "I thought the coffee tasted better," he said simply. He was fired. The next job was unsatisfying. So eight years ago, he left through the underground.

He left a country that gives the white minority salaries 12 times that of black Americans.

He doesn't know if he wants to go back. He doesn't expect to be assimilated into the culture here, either. "I am able to survive because being a South African black I know how to play the game with whites. I know how to always be on my toes," says Rathebe.

"We have problems internationally, nationally and economically, but it is not a crisis," says Prime Minister John Vorster. "I want to make it clear that nowhere in the world have 4 million (whites) done so much for the 18 million (blacks) as in this despised South Africa."

-August 1976

Leading the delegation of white South African diplomats here - approximately 90 people including families - is Donald Sole, a tall, angular man with nearly 40 years in foreign posts.

"When I go through the townships I have a feeling of thankfulness that I have manged to do better. There's no remorse in terms of where we have been in the past," he says, sitting in his study at the embassy.

The officials are all aware of the pressures added to their lives since Southern Africa gained more of the world's attention in the last two years. They admit changes are inevitable, but not one-man, one-vote changes. They speak of economic timetables, and the solution of the "separate homeland" for the blacks, a "solution" many observers have called no solution at all.

"When the economy is stable, then the politicians can be given elbow room," says Johannes DeLoor, now the ambassador to the International Monetary Fund, who is returning home in October to be Secretary of Finance.

Not all the officials are haunted by the politics. Ronald Shuttleworth, the embassy's scientific counselor and a medical school teacher of heart-surgeon Christiaan Barnard, says science provides a level of immunity. "I have received a few unpleasant letters from other scientists but it's very, remarkable rare, in fact."

Even that partial disassociation is rare. For Jeremy Shearar, the embassy's political counselor, the growing tension is very real. "Nobody wants war. We, the government don't want war.The vast majority is against it, and the outsiders, with all the best will in the world, tend to aggravate the situation," says Shearar. "But we certainly want to preserve our way of life."

". . . While police apparently looked the other way, the Zulus attacked not only young militants but anyone who happened to get in the way. When the mayhem in Soweto finally petered out, at least 21 blacks had been slain by fellow blacks, and hospitals over-flowed with the injured."

-Newsweek, September 1976

As blacks in South Africa divide along political and generational lines, the blacks here place the need for kinship above their differences. Jordan Ngubane, 60, a nationalist, gets along with Ngqondi Leslie Masimini, who represents the Transkei government in Washington.

Last October the Transkei, a territory where Masimini was born, and the ancestral home of 3.3 million Xhosa tribesmen, was granted independence by South Africa. Most international bodies, including the United States government, have refused to recognize it as a sovereign state, considering it an entrenchment of apartheid. Even some black Africans have condemned its creation.

"Though we are sharply divided politically we take note of being strangers in a foreign land," says Ngubane, a journalist who left South Africa in 1962. He was vice president of the Liberal Party when Alan Paton was president, and was tried for conspiracy, branded a Communist, and was forced to leave. In Washington Ngubane shares a modest Northwest apartment with a white woman, a coexistence still forbidden in South Africa.

Masimini fled too, after years of fighting through political parties that were eventually banned. He spent most of his youth - he's now 46 - in prison, and since 1962 he's been running. In a way that accounts for his alliance with the Transkei.

Being a refugee, not belonging, not having a home, that's a great frustration," says Masimini. In the last four years, he's become a family man, marrying Barbara Cannady, a Washington-born psychologist. They have three children.

"There have been the same consistent influences in our lives, the same kind of racism, plus the independent thinking you get in an industrial society," says Barbara Masimini, as she explains the cultural similarities between the two black groups.

When they decided to have their baby named in the traditional African way, they called Jordan Ngubane to perform the ceremony.

What promotes solidarity, instead of friction, says Ngubane, is the common pain. "In South Africa the first thing a white takes away is your humanity. There's a pervading diminution of your worth," he says. "The law says you have no right to improve your life."

Johannesburg - Gun dealers here and in Capetown report soaring sales to white South Africans . . . Newspaper ads suggest that what every woman needs as an umbrella that - at the press of a button - produces a 6,000-volt charge.

-News reports, June 1976

The banners waving over Lafayette Park denounced the United States in volvement in Angola. On the platfrm a speaker from the South West Africa People's Organization (SWAPO), a liberation group in Namibia which South Africa has ruled since 1920, now against UN directives, was denouncing South Africa.

Out of the crowd Laetitia Combrinck, a tall, bespectacled woman who appears very timid, walked up to the SWAPO speaker and told him he was dead wrong. As Combrinck tells it, in a crisp, unmistakeable Afrikaans accent, she next turned to two white South African dissidents, asking to talk, but the women made some hostile remarks and walked away.

"I didn't get angry or flustered. I was just unsuccessful at that time," says Combrinck, 39, who has lived here for 10 years and teachers Afrikaans at the Foreign Service Institute.

Even though Combrinck would be considered a conservative in the world's eyes, and once worked for the Rhodesia government here, she describes herself as a liberal thinker. "Once at Georgetown University I had a very encouraging conversation with some black American students. It was cordial," she says. "I'm not a supporter of all the government policies, but I am pro-government."

". . . the whites need us but they don't want us. We're a necessary evil in their eyes and they treat us as such. We're just panws without any say in any important decision that affects us."

-A black personnel consultant, 1976

Jacob Motsi is the first black the white South Africans in Washington mention as an aquaintance.

In 1932 Motsi left, by choice, a South Africa that wasn't as rigidly segregated as the country today. Many years ago he worked at the embassy, and now frequents its offers, insisting that, "these are my countrymen." Yet he didn't escape the oppression of whites at home or here and he still feels very much a South African. Now almost 75 years old, he says, "my mind, blood and soul are with my people."

He serves everybody's purpose, something of an enigma, not really fitting in, but the whites can point to him, as do the blacks, as an older reference point. But some blacks even suspect he's an informer because of his frequent visits to the embassy.

At a recent party at the home of an embassy official, 10 blacks mixed with 20 white guests. The atmosphere was casual, but artificial. Motsi was the most visible and gregarious black. He told the whites and blacks alike that he didn't approve of the divisions of the Bophuthatswana, the next homeland scheduled for independence. Two of the territory's representatives were at the party and Motsi told them he thought the country should be divided in two.

"Oh, I know what they say," says Motsi angrily, as he offers a South African wine for lunch. He lives in a detached brick house, a property he couldn't own in Johannesburg. "They say I'm a spy. But I don't okay the embassy's policy. I am trying to make them feel ashamed about the way they treat blacks at home by seeing how a black with education acts. Yes, I think they regard me as an equal human being."

"The South African government has done more for black people than anyone in the world," said James T. Kruger, Minister of Justice and Police, at a press conference announcing the deaths of 35 blacks in a work boycott protest last August. He also announced the arrest of 744 blacks, and 77 others under the detainment policy. "We are still prepared to do more than anybody in the world. We want to keep our (black) people happy as possible."

'-News reports, August 1976

". . . the male migrant laborers. They are a class of people created by our politicians and an examination of the problem of alcoholism among them reveals graphically how a sick society brings forth sick individuals . . . they drink . . . and they commonly drink heavily . . . because tomorrow will also be a hard day."

-A professor of African diseases, Johannesburg, 1973

"It was no surprise that the bar balls were the first buildings burned in the June riots," says Robert Jacobson, a young white South African doctor now at Georgetown University Hospital. "The kids understood the tragedies of alcoholism."

Jacobson chose to work in Baragwanath Hospital in Soweto, one of the continent's largest medical facilities. He has left the country twice, first for advanced education in the United States, and, now, for a position as director of the hematology lab at Georgetown. But his distance hasn't dimmed his concern. "You can't live in South Africa and not see how the political factors affect you," he says.

"The hospital is one of those places where good black and white contact takes place," he says. Here his contact with blacks continues at the same professional level. Now he has black neighbors in Bethesda. His white South African friends, he says, are professional contacts and he only goes to the embassy to catch up on the newspapers.

In Soweto there are fewer than 50 African doctors in private practice for 1.2 million residents, compared to an estimated 1,400 in Johannesburg for a population of 450,000. A doctor, if he wants, says Jacobson, can do more than dispense medicine.

John Kani and Winston Ntshona, the two South African actors, who won the 1975 Tony Award for their performances in "Sizwe Banzi is Dead," were released and expelled, after being detained in the Transkei.

-News reports, October 1976

One recent evening in Washington four black actors from South Africa sat around a friend's apartment, eating beans and rice, poring over a scrapbook of their reviews and discussing treatment of the artist in South Africa. They all knew Kani and Ntshona and shared their anger.

Three of the four had spent time in prison at home. "But we have no intention of doing plain theater, traditional theater," said one. "Social comment is the street we walk on, it's our life. We take the risks because every move a black makes in South Africa is a political one." For the last six months they had toured college campuses in California with a play called "Survival." It comes close to advocating armed revolution of blacks at home and they hoped to bring it to Washington or New York.

"The whole agony of South Africa is a phenomenon that has to be explained, even acted out," said Temple Mtembu, a South African who now lives in Washington. "After Sharpeville in 1960 I was jailed. And the only way to wash was to flush the toilet and it was common to get electric shock treatments," said Mtembu. Everyone was silent for a while. Then one actor said slowly. "The whole county is a prison. And the irony is that they give us things we don't want. Who needs to stay at a downtown hotel? We don't want handouts, we want our freedom."

The children of Soweto cry into passing automobiles, "Kill! Kill! Death to the whites." Establishment voices like that of Foreign Minister R.F. (Pik) Botha, continue to say "we fear black domination. That is a fact and this is the basis of our policy."

The South Africans in Washington are split similarly into two camps, but the weapons and psychological. Even when blacks and whites do meet, the memory of the years of oppression stands between them, almost tangible. Both sides are keenly sensitive to the news from home, vulnerable to the bite of world opinion.

Says John H. Chettle, the head of the South African Foundation's Washington office. "There's a certain sense of mutual beleaguerment. White South Africans are very conscious of the critical attitude toward them."

As tensions at home increases, reflected in daily news reports, pressures on South Africans here intensify as well. Says U.S. Ambassador to the U.N. Andrew Young. "As long as apartheid is practiced in South Africa, days without violence can be no more than intervals in which tensions build up and hatreds grow."