Saving Reagan's southern Africa policy: views that canceled a trip

''Constructive engagement'' might still provide a productive basis for United States policy toward southern Africa, but serious flaws in implementation these past 10 months already jeopardize the policy's success.

The phrase ''constructive engagement'' was selected by the Reagan administration to suggest a significant distinction from previous US policy toward southern Africa. Yet two of the Reagan policy's underlying principles have been applied (with varying degrees of candor and consistency) by earlier administrations.

One of these is that US strategic interests in the region, which have been modest and only now are growing in recognition of the significance of its mineral resources, must always be given primacy over other US interests; the second is that the US has only limited leverage to aid the resolution of regional conflict and to encourage peaceful change within South Africa.

Another long-established principle - that US commercial interests in the region require governmental support and can make pivotal contributions to regional economic development and to social change - now gets an unusually forthright endorsement.

The two other principles are relatively new: South Africa's economic and military preponderance in the region must be acknowledged and somehow simultaneously inclined toward convergence with US regional interests; and continued criticism of the racist dimensions of South African domestic policy must be balanced by an appreciation of the difficulty inherent in building stable, democratic institutions in that multi-ethnic society and by public acknowledgment when progress is achieved.

The final principle is especially compelling. But consider the mistakes:

First, and most important, the administration has treated South Africa differently from all other interested parties.

It rightly encouraged Pretoria to submit a definitive account of South African concerns about security and economic interests in Namibia and the situation of white residents there after independence. But Pretoria's list appears little different from what it offered the Carter administration during 1980, and there is likely to be a similar process of exhaustive exploration on each point.

To further encourage South African commitment to the negotiations, Washington has ruled out economic sanctions, offered modest incentives instead, and repeatedly warned that the US would pull out from a stalemated negotiation process. Among other things, the administration has responded tentatively to the South African interest in buying enriched uranium to fuel the Koeberg nuclear power station without first adhering to the inspection terms of the nonproliferation treaty. And it has at least tacitly acquiesced in Pretoria's August attacks in Angola by its public statements and vote at the subsequent United Nations Security Council session.

The net effect of US actions and inactions vis-a-vis South Africa has been to strengthen Pretoria's conviction that it remains free to exercise its regional preponderance essentially as it sees fit. Thus, in the final stages of the Namibian negotiation, it is likely to be more intransigent, rather than less. It will give far less weight to US incentives already obtained or promised than to domestic white politics, its ability to withstand attacks without US aid, and its genuine (if nonsensical) conviction of successful administration in Namibia.

Moreover, as long as the Namibian quandary remains unresolved, any prospect for effective US leverage over change within South Africa falls by the wayside. Congress would be reluctant to appropriate money for black education and training in South Africa (a high priority for this administration), and corporations and foundations would be hard pressed by domestic constituencies to minimize their South African programs. Constructive engagement in the republic might never get off the ground.

The policy can be revived, but only if the US makes clear to South Africa three immediate requirements: regional preemptive raids must be halted; the destabilization of neighboring states by economic means and by covert actions must end; and South Africa must pledge itself to irrevocable acceptance of the Namibian electoral results.

Failing the achievement of these requirements, the US should not only end incentives but support graduated economic sanctions against South Africa. These drastic and (for this administration) politically difficult steps would be necessary because a South African refusal would lead to a widening regional war in which the US might be dangerously close to an ambiguous but essentially irreversible commitment to Pretoria.