With Bravery at Both Helms, Prospects for Peace Increase : South Africa: Nelson Mandela has matched the risks taken by President De Klerk. The two have a good chance of pulling off negotiations.

South African President Frederik W. de Klerk took a historic gamble on Feb. 2 when he legalized the black opposition and the Communist Party, and moved to release Nelson Mandela, with other leaders of the African National Congress, from prison.

Now Mandela has taken an equal risk and, if the negotiating minefield ahead can be negotiated, the two leaders have a surprisingly good chance of pulling off the peace process.

Mandela and his ANC colleagues have called off their armed struggle, at least for now. Guerrilla warfare was one of their most powerful cards. Although the 30-year war they waged was far from a resounding military success, the bombs and gunfire concentrated the minds of whites.

Now, clearly, Mandela feels strong enough to suspend hostilities. The question is whether he will get enough in return from De Klerk to pacify the hawks in his own ranks, and the disaffected, jobless and homeless mass of blacks manufactured over the years by apartheid.

There is no other black South African with the stature to pull off these negotiations. Mandela is unique, having been made a living martyr by 27 years of incarceration by successive white Nationalist governments. That he has moved so swiftly to suspend the war confirms the genuineness of his commitment to peace; it is a sign of hope that the vexed South African problem might be successfully resolved in the next few years, if not months.

For De Klerk, the suspension of armed struggle by the ANC is a political godsend. It will make it easier for him to explain to his rather dubious followers why he took that quantum leap in February. Up to now, with world sanctions still in place and violence at home running high, he has had little to offer.

He goes into important National Party discussions this week able to promise his supporters that violence is likely to end. The economy and the stock exchange will respond. Soon the ANC itself could join the call for foreign investment and trade. South Africa could return to the world stage with a bang.

Yes, there is a long way down the negotiation road for both white and black before a workable democracy can be established. The right wing can be expected to continue its campaign against De Klerk, with some fringe elements using violent words and even deeds. De Klerk must beware the fate of Egypt’s Anwar Sadat. The security forces, too, are likely to be a problem, because of their trigger-happy response to black dissent and their years of knee-jerk propaganda against the ANC, which is now a perfectly legal organization.

The radical black groups outside the ANC, feeding on a constituency of unemployed that could run close to one-third of blacks, will be waiting for the ANC to twist its ankle on the tortuous path to peace. But Mandela’s immense stature among most blacks must be reckoned with. It is not easy to take him on.

The violence level in South Africa has been running high, with the South African Institute of Race Relations reporting 1,591 deaths in political violence in the first six months of this year, compared with 1,403 deaths for the whole of 1989. But recent weeks have seen a slight tailing off.

Despite all of the difficulties, there is no doubt that a start has been made. Aside from the ANC’s pledge, Monday saw agreement on the release of prisoners, return of exiles, the framework for a review of security legislation and the state of emergency in warring Natal province. These things, taken together, are the most important step forward in a generation.

Something seismic seems to be happening. The momentum toward peace has gone so far, so quickly, that--whatever the intentions of the players--it seem unstoppable.