IT is important to keep clearly in mind what we are striving for in South Africa. That apartheid will ultimately crumble, there has never been any doubt. The question is whether it will be destroyed in a savage race war or whether it will erode as a result of dialogue and compromise between blacks and whites.
As we have seen from the defiant line laid down last week by South Africa's President P. W. Botha, the refusal of Nelson Mandela to disavow violence, and the weekend depression of Bishop Desmond M. Tutu, who seemed to come close to accepting the inevitability of violence, dialogue will not be easy.
But the alternative is urban terrorism on a scale that would dwarf the present violence in Northern Ireland.
It would tear down the industrial infrastructure that sets South Africa apart from much of the rest of Africa in desperate need.
The choice is clear: bloodshed and a nation in smoldering ruins, or an initially suspicious dialogue with a chance -- just a chance -- of leading to security and justice for South Africans, both black and white.
There are those who have been writing and warning of this choice for more than 30 years. The cruelty of Sharpeville, the agony of many Africans, the shootings and beatings and arrests, and the daily humiliations have gained notice over the years, but not the acute attention now being given South Africa.
Sen. Edward M. Kennedy, and Rep. Stephen J. Solarz, have recently been to South Africa, and though their focus is belated, it is nevertheless welcome and important.
For the Reagan administration, South Africa has not only become a crucial foreign policy problem, but also a significant domestic political issue.
There is a heated debate over sanctions against South Africa. It is pitting Republicans like Sen. Richard Lugar, as well as Democrats, against the Reagan administration. The political climate may guarantee sanctions and force President Reagan to subscribe to them. That may make Americans feel less frustrated; but nobody should be under any delusions that sanctions, by themselves, are going to crack apartheid.
There is also hot discussion as to whether the Reagan administration's policy of ``constructive engagement'' has been any more effective than that of any previous administration in nudging South Africa away from apartheid.
There have been some positive developments. Although Bishop Tutu attacked that policy last weekend as being ``evil, immoral, and un-Christian,'' his own freedom to travel, and perhaps even his security, may, unknown to him, have been enhanced by the ``quiet diplomacy'' that is part of ``constructive engagement.''
Another irony: President Botha's regime has in recent months taken steps in the direction of reform which, though hesitant, greatly exceed anything suggested by his Afrikaner nationalist predecessors.
Of course, all this is academic, because South Africa has been overtaken by the negative, a wave of violence that has seen more than 600 blacks killed.
Earlier reform talk has been dismissed as too little, too late; President Botha with last week's unimaginative intransigence disappointed black South Africans and the world; and the Reagan administration's ``constructive engagement'' policy is being criticized as having achieved zero.
Now some of the same critics who contend that the United States should not be a world policeman are saying the US should somehow step in and solve the South African situation with a whisk of its wand -- or truncheon.
The fact is that President Botha has thumbed his nose at Washington, refusing to deliver last week what the US asked for earlier in Vienna.
He has also consistently held off the United States on Namibia (South-West Africa); 41/2 years into the Reagan administration, South Africa still occupies it.
Thus, American influence on Pretoria is clearly overrated.
President Botha is wrong about a lot of things, yet he is right when he says South Africa's problems will have to be solved by South Africans. But that means presently voteless black South Africans as well as the white South Africans who elected Mr. Botha, and those he serves.
Whatever influence the United States has should be used to inaugurate the black-white dialogue President Botha has so vaguely spoken of. If there is a chance for South Africa, the rhetoric must become reality.
John Hughes is a Pulitzer Prize-winning journalist who was assistant secretary of state from 1982 to 1984.