In one respect, South Africa appears to be a step ahead of negotiators seeking independence for Namibia (South-West Africa). South Africa, according to knowledgeable analysts here, has effectively carved out by force the equivalent of a ''demilitarized zone'' in southern Angola - something the negotiators will have to establish formally in advance of any election.
The latest evidence of South Africa's success in reducing the military threat to itself along the Namibian border is recent disclosure of a raid last month that penetrated 150 miles into Angola - the deepest thrust since 1975. It has further pushed SWAPO (South-West Africa People's Organization) guerrilla forces from their border target areas. And analysts agree South Africa has established a comfortable zone of protection from SWAPO north of the Angola-Namibia border.
The raid is seen as a good omen here for the independence talks. Those who have followed the Namibia issue for years say the raid fits a long-established pattern of South Africa making diplomatic concessions against a backdrop of military muscle.
Beyond strategic objectives, a show of military force accomplishes two things from the South African point of view: (1) It demonstrates to the local population that the government is not ''surrendering'' Namibia, now administered by South Africa, through the negotiation process; and (2) it is expected to undercut SWAPO's image as a military ''liberation force'' and therefore its political chances at the polls.
''South Africa definitely sees a link between SWAPO at the polls and SWAPO in the battlefield,'' says Namibia specialist Andre du Pisani of the University of South Africa.
The disclosure of the raid by South Africa roughly coincided with unofficial but reliable reports here that the government has agreed ''in principle'' to a set of broad constitutional principles for an independent Namibia. The principles were drawn up by the ''contact group'' of Western nations - the United States, Canada, Britain, West Germany, and France - that are spearheading the negotiations for a Namibia settlement.
That means South Africa now joins the other principal actors in the Namibia issue in a willingness to move on to the second phase of negotiations. The key African ''frontline'' states (Angola, Zambia, Botswana, Zimbabwe, Mozambique, and Tanzania) and SWAPO have given the proposals qualified acceptance. Western negotiators reportedly are weighing how to begin the next phase of talks.
The stakes are high all around. The US has adopted what might be described as a pro-South Africa policy, betting a settlement in Namibia would result. And US relations with black Africa could lie in the balance since most African nations see Namibia as an offensive remnant of colonial rule and one of the issues most needing resolution in Africa.
Namibia's potential as a destabilizing force in southern Africa is clear. SWAPO's presence in Angola is South Africa's justification for raids into that country. And Angola justifies its need for Cuban troops on the basis of needed protection from South Africa.
From the start of the current round of negotiations the US has held the view that the greatest concession belonged to South Africa. That is, the end of its rule of Namibia.
But analysts here say it is clear that South Africa increasingly recognizes that Namibia must gain independence in an internationally acceptable manner and that the best possible time for a settlement may be now.
''The whole equation points to a settlement,'' says Professor du Pisani. Further, he asserts, ''the context is completely different now'' for South Africa and more favorable for a settlement than at any time in the past.
The friendship of the Reagan administration and the growing focus of the South Africa on internal matters make the status quo in Namibia an increasingly costly option to South Africa, du Pisani says.
The Namibia war is costing South Africa about $1 million per day. Last year war casualties were estimated at 1,500 for SWAPO and 76 for South Africa.
South Africa has two basic objections regarding the proposed set of constitutional principles for Namibia.
The proposals called for a ''unitary'' state of Namibia. To South Africa the term implies a potential ''domination'' over all spheres of the white minority, says one informed observer. South Africa apparently also seeks a more explicit definition of how the different ethnic groups will be accommodated in a national constituent assembly.
The second phase of the negotiations will by all accounts be the most difficult. It must devise a formula for a United Nations-supervised election that both SWAPO and South Africa agree is fair.
South Africa is concerned about impartiality. The UN considers South Africa's occupation of Namibia ''illegal.'' And the UN recognizes SWAPO as the ''sole legitimate representative of the Namibian people.''
Publicly, South Africa has been noncommital about the newest round of Namibia talks. Just last month Prime Minister P. W. Botha lauded the fact that South Africa's relations with the US had been marked by ''greater realism.'' But he warned that while a ''fresh attempt'' was being made to resolve the Namibian issue, ''there are still major and delicate negotiations in store for the parties involved in the matter.''
Special correspondent Louis Wiznitzer reports from the United Nations:
UN diplomats are cautiously optimistic about the Namibia negotiating process.
Phase 1 of the Western contact group's Namibia initiative - agreement on a set principles to be in Namibia's future constitution - has been completed.
Phase 2 will be launched in January and Phase 3, the final one, ought to be deployed in March 1982.
The basic tenets of Phase 1 are: a multiparty political system, an independent judiciary, protections for the white minority, a bill of rights, protection of private property, and ratification of the constitution by a two-thirds vote of the national legislature.
Phase 2 is expected to present more difficulties. It addresses South African concerns about how to assure:
* UN impartiality in supervising free elections in Namibia.
* The deployment and the composition of the UN forces in Namibia during the intermediary phase.
South Africa has claimed consistently that since the UN General Assembly recognizes SWAPO as the ''sole legitimate representative'' of the people of Namibia it cannot be expected to act as a fair referee during the electoral process. The contact group will remind South Africa that General Assembly resolutions are not binding and that once the plan begins to be implemented, the UN will act under the authority of the Security Council and not of the General Assembly. In fact, all previous UN resolutions will be discarded.
Once Phase 2 is complete, Phase 3 would design agreement under UN auspices among all the parties regarding implementation of the UN plan. It could take effect as early as March or April 1982. Namibia could become independent in the spring of 1983.