Prime Minister Robert Mugabe was in a jovial mood as he poked fun at Zimbabwe's whites in a speech to several thousand domestic servants in a wealthy Salisbury suburb.

"Those rich people cannot live without your work. Their women cannot clean, cannot wash. Some of them cannot even dress themselves. We have made them alive from head to toe," the Zimbabwean leader said.

Each charge was punctuated by laughter and cheers yesterday from the servants, who then trudged back to the palatial homes they serve to prepare Sunday supper.

The humor hid the fact that two years after this southern African nation achieved independence, Zimbabwe, regarded as a model for potential change in racially segregated South Africa, is agonizing over the state of race relations.

Mugabe's much-heralded policy of reconciliation provided a brief honeymoon after a bloody, seven-year guerrilla war, but now black-white relations have reached a point at which many here now believe the government's attempts to form a multiracial society are endangered.

In a series of interviews and weekend political rallies, Mugabe has spoken of his disappointment at what he feels is the failure of whites to respond to reconciliation. Editorials in the press, discussion programs on the government-controlled radio and television and church sermons examine the subject.

Former prime minister Ian Smith, who vowed to maintain white-minority rule and led the country, then known as Rhodesia, into a war to preserve it, says that "the government has embarked on a policy of deliberately destabilizing white people" by "hurling abuse" at them.

To many blacks, on the other hand, Mugabe is finally engaged in moving government activities into the economy where white domination ensures a clash.

This broader sense of racial antagonisms has arisen as racial tension between individuals seems to have declined since a spate of incidents shortly after independence in April 1980. "There is relative peace between the races," Justice Minister Simbi Mubako said recently.

Black and white communities, nevertheless, rarely meet socially, and many now are questioning whether a black-ruled nation whose population is 97 percent African can long maintain stability when there are two separate societies and the smaller is the privileged one.

The confrontation is basically political, particularly in the area of security where increasing government concern about neighboring, white-ruled South Africa is overriding. South Africa was the ally of the former white government, and many Africans feel that old habits die hard among the whites.

The turning point for Mugabe came in November when a white South African still in the Zimbabwean Army, Capt. Frank Gericke, was arrested on suspicion of spying and then escaped from detention, allegedly with the assistance of a white detective, Fred Varkevisser. Both are believed to have gone to South Africa.

"It was like waving a red flag," a source close to the prime minister said.

Mubako said the government must ask, "How many more white police and white soldiers can we trust?"

Since then, about a dozen whites, including a member of Parliament and three security officials, have been arrested on suspicion of antigovernment activities under emergency regulations retained from the Smith era. The member of Parliament, Wally Stuttaford, is suing over charges of physical abuse during his imprisonment.

Mugabe has frequently accused Smith of subversion without giving any details and has threatened to have him arrested. He accused some whites of having "one foot in Zimbabwe and another in South Africa."

An explosion at his party headquarters before Christmas, cheered by some whites, exacerbated matters. In the military, "blacks suspect the whites," Mugabe said and gave an example. He said a black commander had recently "broken up" a celebration of white officers at a military base in which they wore old Rhodesian uniforms and displayed the coat of arms and flag of the former government.

"So you have this persistent commitment to the past, which is really a refusal to recognize the change that has taken place," he said. "We didn't forgive Smith so he could continue planning the subversion of the state."

Several antiwhite incidents have occurred in this atmosphere of suspicion. A number of tourists, foreign and Zimbabwean, have been harassed or assaulted when they strayed into a camp in southeastern Zimbabwe where North Korean soldiers are training troops.

Fourteen elderly men and women were stopped at gunpoint by a major general and a brigadier and held overnight after a game of lawn bowling at a military headquarters.

Fewer than one third of the 3,000 whites in the military at the time of independence are still serving. The attrition rate among police is greater.

Fearing for their future, whites have either rallied around Smith, whose party holds all 20 white reserved seats or have decided to opt out of the political system altogether. In a white by-election last July only 29 percent of those eligible voted.

"The whites are psychologically expatriating themselves. It's no longer their country," a Western diplomat said.

There are wide differences between Mugabe's and Smith's parties over what reconcilation means.

Eddison Zvobgo, minister of local government and housing, said recently: "Reconciliation means forgiveness, yes, forgetting no . . . . We must never again allow a clique to dominate over others." He called for whites to denounce the past and unite with Mugabe.

Smith, on the other hand, said in an interview that the country's past "is one of the proudest histories ever recorded."

Repeating his stance of the last two decades, he said, "Our blacks are better off then anywhere else in Africa. We've given these people the jewel of the African continent. They should be grateful and stop hurling abuse at white people."

"Do you want the whites to stay or not?" he asked. About one-sixth of the estimated 200,000 white population at independence has left. The trend is moving upward, leading to a deterioration of sevices in such fields as transportation, telecommunications and power.

Since it is impossible for Mugabe to meet all black expectations for land, jobs, advancement and social services, Smith and his party provide a convenient scapegoat in the prime minister's weekend political rallies.

Acknowledging this, a black official said, "One has to distinguish between weekend and weekday speeches."

"The whites were always told that if Mugabe took power there would be chaos and disaster," another black official said. "When that didn't happen they didn't know how to react. They still don't."

Roger Riddell, a white economist who was exiled from the country during the Smith years, was more optimistic.

"The political confrontation is in a narrow sphere," he said. "What is being debated in Parliament by the Republican Front Smith's party is irrelevant. What is important is to achieve expansion of business, industry and agriculture."

In these areas, the economist for the Confederation of Zimbabwe Industries said, "The whites are beginning to learn how to work with the system."

One of the few high-level black business executives, however, noted that the private sector was still very much of a white preserve; many whites have fled to business from the civil service, where more than half the senior positions are now held by blacks.

Whites in business are understandably refusing to train blacks, he said, for fear of working themselves out of a job.

Many whites are now more circumspect, a long-time white liberal said, but "they haven't changed in their hearts."

She told of what happened when an all-white department in a school got its first black teacher. The white teachers cut out their tea break, fearing they might have to drink out of a cup used by a black.