What next for South Africa?

THE sweeping and brutal crackdown in South Africa has produced a worldwide demand for sanctions. President Ronald Reagan and Prime Minister Margaret Thatcher are lonely holdouts. For most, the debate is about what measures and with what aim. Apartheid cannot last indefinitely. The question is whether its end will come eventually through a long, bloody, and tragic struggle or through some process of negotiation.

In December the Commonwealth named a seven-member Eminent Persons Group (EPG) to work for a nonviolent outcome. Its mission was to foster political dialogue between the Botha government, which has repeatedly promised to end apartheid and share power in a new democratic order, and representatives of the black population to achieve peaceful reform.

After six months of dedicated effort, the EPG failed to get the Botha goverment to the negotiating table. Does that mean that a nonviolent solution is hopeless?

Certainly the prospects are discouraging. In the decade since the Soweto uprising, black opposition to apartheid and white domination has grown much more militant and widespread. It now embraces churches, communities, black businesses, and unions. The blacks' most revered leader, Nelson Mandela, has been in prison for 24 years, and his organization, the African National Congress (ANC), is banned.

But the blacks are split among various organizations. Some favor a multiracial democracy, while others want an all-black society. Some seek nonviolent change, while others are committed to violence.

The whites are also deeply divided: There are Afrikaner extremists dedicated to apartheid at any cost, liberals long opposed to the system, and many who could probably be led reluctantly to accept the necessity of dismantling apartheid and sharing power if there were minority safeguards and a phased transition.

Much of the business leadership is now pressing for peaceful reform.

Replacing apartheid with a democratic order is bound to be a protracted process. Even if the 5 million whites agreed to share power with the 25 million blacks, they would surely insist on an extended transition period. And if the extremists hold control, they may well be able to repress the blacks for some years by the Army and police, with violence escalating on both sides. The capacity of outsiders to encourage peaceful change is extremely limited.

The stakes for both white and black are their future way of life. Yet the alternative is so ghastly that outsiders must surely use whatever leverage they have to try to improve the odds for a negotiated outcome. The approach of the EPG seems the most practical one. It sought to promote negotiation by:

Pressing the Botha government to end its state of emergency, release Mandela and other political prisoners, and end detention without trial. The EPG urged the government to lift the ban on the ANC, allow free assembly and political activity, and commit itself to dismantle apartheid.

Urging the ANC to enter negotations while agreeing to suspend violence. Mr. Mandela did agree to do so, but the government demanded total renunciation indefinitely, a concept Mandela and the ANC rejected. Since the EPG effort by persuasion failed, the only recourse is some form of economic pressure, as the EPG recognized.

Should any sanctions be comprehensive or selective?

Total sanctions could gravely damage the South African economy, though the ANC has said blacks are ready to bear the costs. But it is uncertain whether sanctions would tend to drive whites together and whether the major trading nations would stick with a complete embargo for very long. Initially, at least, it may be more realistic to adopt selective sanctions aimed at inducing the business community to make greater efforts to bring about negotiated reforms to avoid catastrophe.

Financial restrictions are likely to be easier to apply and enforce. Foreign companies might be pressed to add their leverage. And if these selective measures do not work, the option remains to increase the pressure.

The difficulties of negotiating so radical a shift in political power are obvious. Whites will consent only to avoid starker alternatives. Blacks will have to accept safeguards for the minority and a sufficient transition to allow whites to adjust and blacks to prepare for their new power and role.

Robert R. Bowie has been concerned with foreign affairs for nearly 40 years on the Harvard faculty, in government posts, and as a consultant.