For a long time it has been speculated that South Africa's Prime Minister Botha would pursue political and diplomatic reforms in line with his early ''adapt or die'' warning -- if only the hard right wing of his National Party were not holding him back. Will the reforms come now that he has taken the extraordinary step of eliminating major opponents from the party?
The good opinion of the outside world has never seemed uppermost in Mr. Botha's mind. But he can hardly be unaware of the view that the time is ripe for South African initiatives, that Pretoria cannot count on future American and British governments being as supportive as the present conservative ones. He must know, too, of the international businesses in South Africa that are concerned about the stability and effectiveness of work forces going home each night to conditions of apartheid and exclusion from the political process.
All this added to the internal pressure from black South Africans whose remarkable patience keeps being tested -- and from the small liberal political opposition. Just after the National Party's split, it suffered municipal-election losses not only to the right but to the left. The Progressive Federal Party, which rejects the apartheid policies of racial segregation, came within one seat of a majority on the Johannesburg City Council. Its victories in two wealthy suburbs gave it control of major urban areas for the first time, though still confronted by Nationalist provincial and national supremacy.
The issue on which the Nationalist Party split was Mr. Botha's effort for limited ''power sharing,'' providing political representation for Indians and Coloreds (persons of mixed race) though not for the black majority. He expelled 16 rightist members of parliament from the party when they persisted in opposing him.
The action was seen as enhancing Mr. Botha's present control over the party while inviting increased far-right opposition down the road. It can only be hoped by South Africa's well-wishers that he has gained enough time and strength to move forward on Namibian independence as well as domestic reforms.
Limited power sharing might be greeted cynically when the need is for representation of all the people. No doubt the return argument would be used, as with the advisory multiracial Presidential Council, that black people can be omitted because they have political representation in the ''independent'' homelands provided for them -- a meaningless representation in terms of South African rights. A move for representation of Indians and Coloreds is no substitute for political participation by the whole population.
But every such step must be welcomed. And the progress of a National Party minus obstructive right wingers will be watched with the greatest interest.