It is because state President Botha has presided over these reforms that extremists have denounced him as a traitor. We must remember, as the British historian Paul Johnson reminds us, that South Africa is an African country as well as a Western country. And reviewing the history of that continent in the quarter-century since independence, historian Johnson does not see South Africa as a failure. ''Only in South Africa,'' he writes, ''have the real incomes of blacks risen very substantially. In mining, black wages have tripled in real terms in the last decade. South Africa is the only African country to produce a large black middle class. Almost certainly,'' he adds, ''there are now more black women professionals in South Africa than in the whole of the rest of Africa put together.''

Despite apartheid, tens of thousands of black Africans migrate into South Africa from neighboring countries to escape poverty and take advantage of the opportunities in an economy that produces nearly a third of the income in all of sub-Saharan Africa.

It's tragic and in the current crisis social and economic progress has been arrested. And yet, in contemporayy South Africa, before the state of emergency, there was a broad measure of freedom of speech, of the press and of religion there. Indeed, it's hard to think of a single country in the Soviet Bloc, or many in the United Nations, where political critics have the same freedom to be heard as did outspoken critics of the South African Government. To Dismantle Apartheid

But by Western standards, South Africa still falls short - terribly short - on the scales of economic and social justice. South Africa's actions to dismantle apartheid must not end now. The state of emergency must be lifted. There must be an opening of the political process. That the black people of South Africa should have a voice in their own governance is an idea whose time has come. There can be no turning back.

In the multiracial society that is South Africa, no single race can monopolize the reins of political power. Black churches, black unions and indeed genuine black nationalists have a legitimate role to play in the future of their country. But the South African Government is under no obligation to negotiate the future of the country with any organization that proclaims a goal of creating a Communist state, and uses terrorist tactics and violence to achieve it.

Many Americans understandably ask, given the racial violence, the hatred, why not wash our hands and walk away from that tragic continent and bleeding country. Well, the answer is, we cannot. In southern Africa, our national ideals and strategic interests come together. South Africa matters because we believe that all men are created equal and are endowed by their Creator with unalienable rights. South Africa matters because of who we are. One of eight Americans can trace his ancestry to Africa. p/u/ first and last add prexy text.

Strategically, this is one of the most vital regions of the world. Around the Cape of Good Hope passes the oil of the Persian Gulf, which is indispensable to the industrial economies of Western Europe. Southern Africa and South Africa are repository of many of the vital minerals - vanadium, manganese, chromium, platinum -for which the West has no other secure source of supply.