CRACKS are appearing in one of the world's most enduring and forbidding walls of diplomatic hostility, that separating South Africa and the Soviet Union. It is unlikely that a Soviet diplomatic mission will soon open on South African soil, where no East bloc country is formally represented. But events in the past year have made that prospect less remote.
A hint of possible rapprochement came in February when the normally outspoken foreign minister, Roelof Botha, pointedly and apologetically refused to respond to a reporter's question about Pretoria-Moscow links. Botha said the subject was too delicate to comment on.
But the event placing Moscow-Pretoria relations in the forefront of the news media here was last year's hard-won diplomatic battle for a settlement to the conflicts in Angola, a staunch ally of Moscow, and Namibia, which is under South African control.
The long-standing Soviet view has been that formal diplomatic links with South Africa are impossible until apartheid race laws are abolished. And South Africa's ruling National Party has, for its part, consistently blamed Moscow for fomenting black unrest and encouraging leftist guerrilla movements.
But some Soviet attitudes - notably concerning the African National Congress (ANC), the banned anti-apartheid organization - appear to be changing.
On March 15, Moscow called for political dialogue, rather than intensified military action, to bring an end to apartheid. This statement appeared to confirm a shift away from support for armed action by the ANC.
Even before this statement, however, South African analysts had detected what they term sharp changes in Moscow's approach to this country.
Researchers from the independent South African Institute of Race Relations visited the Soviet Union recently and produced a booklet detailing growing contacts in the past year: A correspondent for the government newspaper Izvestia has visited South Africa, and South African journalists and academics have visited the Soviet Union or met with their Soviet counterparts in third countries. And, over the years, business relationships have existed, notably through De Beers corporation which has marketed Soviet diamonds.
``The superpower which had been accused repeatedly by [Pretoria] of waging a total onslaught on South Africa ... now appeared to be talking a language which sounded similar to that of anti-apartheid moderates within the country,'' the booklet said.
The writers concluded that Soviet policy was based on two principles: first, the Soviet Union did not want to install socialism in South Africa, and second, that Moscow would prefer a political settlement to the overthrow of apartheid by force.
These shifts do not mean that Moscow can accept a political settlement which would entrench white privilege, the booklet says. But ``Soviet policies are no longer cast in stone - indeed for a variety of reasons they may well be more fluid than the approaches of anti-apartheid activists in the United States.''