S. Africa tries to cool expectations for reform. Leaders debate how to placate world without alarming whites

The South African government is trying to dampen expectations that President Pieter W. Botha will announce major policy changes when he addresses a National Party meeting tomorrow night. Two factors appear to be at work: The government itself is divided over how to present any coming policy changes. Certain elements of the government are eager to convince the outside world that fundamental reform is under way. Others are more concerned with not alarming the ruling National Party's conservative white constituency.

Pretoria is aware that its definition of reform differs greatly from what is being demanded by outsiders as well as its own black critics. What the ruling National Party regards as radical change is often rejected by critics as mere adjustments to apartheid, the nation's policy of strict racial segregation.

It was the government itself which was partly responsible for creating hopes that major changes were in the pipeline, including the possible release from jail of black nationalist leader Nelson Mandela. But President Botha seemed to dash those hopes Monday when, in talks with Rep. Stephen Solarz (D) of New York, he compared Mr. Mandela to imprisoned Nazi war criminal Rudolph Hess.

Further elaboration of this government position came from the minister of cooperation and development, Gerrit Viljoen. He said ``exaggerated expectations'' about Botha's speech would result in its being rejected as a failure for not fulfilling hopes. Mr. Viljoen said reform must acknowledge South Africa's racial diversity and take place in a framework of ``principles'' of segregated residential areas, schools, and political institutions.

His language contrasted sharply with that of Foreign Minister Roelof Botha (not related to President Botha), who, in talks with United States officials in Europe last week, characterized pending changes as a watershed in the government's reformist policy. The explanation for this may be that the Foreign Minister put a gloss on the changes which the President and Viljoen, with their gaze on the white electorate, now want to remove.

Changes in apartheid are not seen by the government as interim steps toward black majority rule, which Pretoria opposes. The National Party holds that majority rule is inappropriate since the country is made up of a number of minorities, including whites and various black tribes. Critics charge that this is just a convenient rationale for maintaining white rule.

Apartheid in its pristine form assumes that the 24 million blacks (compared to less than 5 million whites) are not citizens of South Africa but of their original ``tribal homelands.'' Pretoria says it is committed to helping these homelands develop, though most remain backwaters of poverty.

When homelands are designated ``independent,'' blacks who associated with the territory by language, whether or not they live there, are stripped of South African citizenship. This policy carried to its conclusion would result in South Africa not having any black South Africans. Millions of blacks remaining in white-designated South Africa would only be considered aliens or guest workers.

But President Botha has hinted at altering this basic policy of apartheid. Last April he said, ``The government does not regard the loss of South African citizenship to be the inevitable result of a national state becoming independent. We are prepared to negotiate further . . .'' The statement amounts to a repudiation of classical apartheid, as it turns away from the policy of whittling down the number of legally recognized black South Africans.

Botha is expected to expand on this apparent policy shift and announce plans for a common South African citizenship tomorrow. For blacks though such changes mean little if they do not include greater political rights.

A corollary to the territorial seperation of blacks under apartheid is that blacks, as aliens, would have no political rights in white South Africa, especially in the central government.

Yet in another move, President Botha has conceded that blacks should have the right to representation at the highest level within white-designated South Africa.

Botha has turned his back on other principles once sacroscant. He has opened the way for the granting of freehold title to land for blacks in designated white areas and ended the ban on interracial marriage and sexual relations. He has overturned a law that used to prohibit multiracial political parties. And has been a de facto scrapping of compulsory segregation at universities and private schools.

The area in which many analysts feel Botha has introduced the most significant reforms is the economic sphere. Black unions have been legalized and job discrimination against blacks has been reduced. Botha has also opened up the previously all-white Parliament to Coloreds (persons of mixed race descent) and Indians. Blacks, however, remain excluded and are greatly restricted in where they can live and work.

Whether Botha's speech will be hailed as a bold reform initiative or condemned as a tepid modification will depend largely on one's perspective. But indications are that it will not arouse much enthusiasm beyond the ranks of the party faithful.