At journey's end, white South African liberals face key mission. After meeting with black nationalists, dissidents seek to prove value of talks

The key part of the mission of white-liberal South African dissidents who journeyed for talks with the outlawed African National Congress began only yesterday - with their stormy return home. Moving to avert possible violence, police dispersed an airport crowd of right-wing extremists, and persuaded the returning political pilgrims to cancel a planned news conference.

One participant in the talks with the ANC, the largest and most important black antigovernment group, quipped of the cancellation of the airport news conference, ``We demand the right to be protested against!''

His joke touched on a political fact of life in South Africa: in order to represent anything more than a footnote to the country's ongoing political conflict, the returning negotiators must now convince a significant number of fellow whites that the talks, held earlier this month in the West African city of Dakar, Senegal, were useful.

Failing that, the conferees must at least manage to use their controversial visit to provoke a new debate among white South Africans over the ANC.

To the government, and the extreme right, the ANC is a band of terrorists, out to overturn the current system and install a communist dictatorship. Only two months ago, the government parlayed a tough stand on ``ANC terrorism'' into a landslide reelection victory in white-national elections.

To the returning white trekkers, however, the ANC is a group forced, by decades of white-minority domination, racial discrimination, and reprisal against peaceful protest, to turn to violence.

Aware of the critical nature of this stage of their mission, the returning delegates vowed to seek out leaders of the right-wing protest at the airport to talk to them about the Dakar visit. To say there has been no interest in such discussions from the far right, is an understatement.

So far, signs indicate that the Dakar negotiators will have their work cut out for them in charting the domestic follow-up to their talks.

Liberal newspapers here have been predictably warm in their comment on the Dakar conference - portraying it as a first, and necessarily inconclusive, step in an ``ANC debate'' crucial to stable, racial coexistence in South Africa.

But interviews with whites of various political, economic, and social backgrounds suggest widespread skepticisim that such exercises can do much more than encourage antigovernment violence. South African officials suggest that the government, using similar reasoning, may take the offensive against the Dakar conferees when the white chamber of Parliament reconvenes next week.

Complicating the task of the returning whites is the fact that, despite broad areas of agreement in Dakar on some issues, the ANC held firm on the question of greatest interest to South African whites: violence. The ANC did join the white visitors in declaring ``preference'' for a negotiated resolution of South Africa's political problems.

But the ANC delegates also reiterated their view that it is unrealistic, illogical, and unfair to expect them to forswear violence until the government takes steps to make unfettered debate possible. The steps envisaged include the unbanning of the ANC, outlawed since 1960; and the unconditional release of ANC leader Nelson Mandela. In 1964, Mr. Mandela was jailed for life in connection with sabotage attacks by the ANC's then-fledgling military wing.

A government official - among a quiet minority that sees eventual talks with the ANC as key to activating the government's own platform for ``power sharing'' with blacks - says privately that the Dakar visit will push government-ANC contacts much further away.

His reasoning is that such talks must be gradually prepared beyond the glare of television lights and the clatter of public rhetoric. Now, he says, ``it seems likely the government will again come down hard against talking to the ANC.''

The hope of the Dakar conferees is that once the storm over their visit has died down, they can convince a widening number of influential whites - ever closer to the political center - to attempt similar contacts with ANC officials.

The result, they say, would be to place the ANC's use of violence in historical perspective; and allow whites to paste names and faces and handshakes to the government-encouraged image of the ANC as a communist- front terror group.

``There is this perception of the ANC as cutthroats running around the bush,'' returning delegate Christo Nel told reporters. He said the talks had succeeded in demonstrating that, given proper political conditions, the ANC is ``committed to peaceful negotiations.''

Journalists in South Africa operate under official press restrictions.