The east wind of world revolution forecast by Mao Tse-tung has lost much of the threat it once held for white power in South Africa, according to some leading officials and businessmen here who see China's changing foreign policy as the missing key piece in the power puzzle of southern Africa.

"I would vote with both hands for good ties to Red China," Jan Marais, one of South Africa's most prominent financiers and a spokesman for white business and professional groups, said after a recent trip to Hong Kong.

"The Chinese need the resource we have, they have learned about Africa in recent years and we, they and the Western countries have a common enemy - the Soviet Union," Marais said in his Trust Bank headquarters in Cape Town.

At the heart of this calculation is the hope that Peking's aggressively anti-Soviet foreign policy will lead China to soften its once important backing for black revolutionary groups in southern Africa even more and become more tolerant of white rule here as the Soviet presence increases in this region.

The Soviet Union is backing black guerrillas in Rhodesia's border war, supports the radical governments in neighboring Angola and Mozambique and helps the African National Congress, one of the two main South African black exile groups.

Analysts who have emphasized, in private, the importance of a Chinese-American connection in this region to oppose Soviet efforts range from Henry A. Kissinger to black South African political leader Robert Sobukwe, jailed for nine years by the white government [WORD ILLEGIBLE] under partial house [WORD ILLEGIBLE]

"In our [WORD ILLEGIBLE] Kissinger put heavy emphasis on the Chinese reaction to our moves in Angola," Sen. Dick Clark (D-Iowa) recalled on a trip here in early December. He spent [WORD ILLEGIBLE] of his time in our discussions saying that China would think we were weak if we stayed out of Angola."

Clark, head of the Senate African Affairs Subcommittee, played a key role in the congressional refusal to continue the secret financial and material support sought by Kissinger for two Angola guerrilla groups during that country's civil war last year.

The two groups, Holden Roberto's National Front for the Liberation of Angola (FNLA) and Jonas Savimbi's National Union for the Total Independence of Angola (UNITA), were supported extensively by the South Africans, but were beaten by the ruling Popular Movement for the Liberation of Angola (MPLA) and Cuban army units, aided by the Soviet Union.

Angola appears to have been a watershed for Chinese policy in southern Africa, a region pronouced "ripe for revolution," by Chou En-lai in 1965.

At the turn of the decade, China was supplying some weapons to the MPLA, in competition with the Soviet Union, and was training and supplying guerrillas fighting in Mozambique.

Peking's decision to send thousands of Chinese workers to build the railway linking Tanzania and Zambia led South African Prime Minister John Vorster in 1971 to brand "the Chinese bridgehead" in Africa as "the greatest single threat in Africa at present." The government here then portrayed China as trying to turn Africa into a dumping ground for excess population.

At about the time Vorster was making his judgment, Chinese foreign policy was undergoing major shifts, evidently in response to the collapse of the Cultural Revolution and a decision to put opposition to the Soviet Union before all other foreign policy objectives.

By 1972, Richard Nixon was welcomed to Peking, the Chinese foreign minister went to Tehran to praise the Shah of Iran as the leading power in the Persian GUlf, contacts were made with conservative sheikhdoms in that region and aid to guerrilas there was cut back sharply.

In Angola, the Chinese were also apparently changing horses. When the civil war broke out in 1975, Western reporters saw large quantities of Chinese arms being used by the troops of Roberto and Savimbi.

But, Sen. Clark recalled, the Chinese "got out very early" in contrast to the United States "even though they had made the first big commitment" to the FNLA. Clark declined to speculate on why the Chinese shut down their aid by the early summer of 1975, at about the time South African involvement in Angola was beginning.

Today, South African officials no longer hammer the Chinese in their public statements and speeches. Information and Interior minister Connie Mulder paused during an interview alter denouncing "communism's aim of dominating, first South Africa and then the rest of the world" to spoecify, "I mean Moscow by that, not Peking."

Blocked to a large extent from marketing its exports in black Africa, South Africa is "being forced to turn to the East for markets, in places that would surprise the world," a senior official at the South African Reserve Bank said in a clear hint that the business links Marais wants to promote with Peking may be more advanced than is publicly known.

How far the unlikely friendship between Pretoria and Peking will go is problematic. In its campaign to cultivate stronger links with other diplomatically isolated countries such as Israel and some Latin American dictatorships, South Africa has also been courting Taiwan in recent years.

One of the keenest judges of China's intentions in this region is Robert Sobukwe, who was head of the Pan African Congress political movement before he was arrested and the party was banned in 1961. The Chinese provided some support for his group after Moscow began backing the African National Congress.

Sobukwe, however, cannot voice his views publicly. Released from prison in 1969, he has been banished by the government to the mining town of Kimberley, where he remains under a modified form of house arrest at [WORD ILLEGIBLE] . He is also forbidden by law [WORD ILLEGIBLE] giving interviews or publishing [WORD ILLEGIBLE] ideas.

If he could give interviews, Sobukwe would emphasize his view that the key factor here now is "the belief of the Soviet Union and China that black governments will take over" in Rhodesia, Southwest Africa (Nambia) and South Africa, "they are beginning to decide which black governments it will be, and not worrying about giving white minority governments a few more years.

"The United States is allowing the Russians to get all the mileage out of change in this region. Anybody interested in keeping the Reds out of power and stopping the Russians will have to build up their relationship with China," Sobukwe would say.