South Africa's decision to go ahead of its own elections in Namibia by the end of this year is bound to provoke greater Soviet and Cuban involvement in the South African administered territory.

The New South African "go-it-alone" policy seems destined to have far-reaching consequences for both American and Soviet policy in southern Africa and to undermine the whole U.S. attempt to reduce the Soviet-Cuban presence through peacefully negotiated settlements of the racial conflicts burning in this region.

It appears to represent a hardening of the lines between the militarily powerful but increasingly isolated white ruled nation and the black countries to its north which supports the Southwest African People's Organization carrying on a guerrilla war for Namibian independence from South Africa.

In response, black Africa is almost certain now to push for the imposition of economic sanctions on South Africa with the full backing of the Soviet bloc. This promises to place Western nations, particularly the United States. France and Britain with their large investments in South Africa, in a politically embarrassing position.

To avoid such a predicament, the United States spearheaded the Western initiative to draw up a plan for the independence of Namibia and succeeded in gaining the full backing of the five front-line African states: Tanzania, Zambia, Mozambique, Angola and Botswana.

In effect, Prime Minister John Vorster and his government may well have shattered with this one blow the entire basis of Western diplomacy based on the search for an internationally acceptable solution to the conflicts of southern Africa.

The grim prospect now is for an escalation of warface not only in Namibia but in Rhodesia as well. If this happens, there is virtually no chance of Cuba withdrawing its troops from Angola and a good possibility more will be sent to bolster the defenses of Zambia and Mozambique against Rhodesian air attacks.

Among its many othr consequences is likely to be greater South African military support for the beleaguered white-led biracial government in Rhodesia now fighting desperately for its survival against nationalist guerrillas armed and trained by the Soviet Union and Cuba.

There are already unconfirmed reports that South Africa, which provides the Rhodesian government with most of its war material, has discreetly stepped up its assistance recently by providing some manpower once again.

For the front-line African nations involved in the Rhodesian and Namibian disputes, the South African declaration promises many heavy consequences. Zambia and Angola have already paid dearly in lives for their support of SWAPO numerous South African raids into their territory to hit guerrilla bases.

The five nations played a crucial role in mid-July in practically forcing SWAPO to accept the Western peace plan for Namibia despite the nationalist group's many reservations about it. All of them were determined to see a negotiated settlement even if that meant SWAPO had to run the risk of participating in an election with its South African-supported political enemies.

Only last week, Zambian President Kenneth Kaunda let it be known that both Zambia and Angola had called upon SWAPO not to attack South African military positions inside Namibia so long as there remained a good possibility for the amended Western plan to be implemented.

Now, they will undoubtedly feel themselves morally and politically obliged to back up any escalation of guerrilla warfare by the Namibian nationalists in retaliation for the South African decision to hold its own elections.

Another of the many indirect consequences of this act on the volatile politics of southern Africa may be to undermine the detente exercise now under way between Communist-backed Angola and Western-supported Zaire.

Angolan President Agostinho Neto had strongly backed the Western plan for Namibia in the hope that once South Africa was out of that country, Pretoria would cease aiding dissidents still fighting against his government in southern Angola.

Now, it seems probable that a South African-backed government will emerge in Namibia, permitting Pretoria to contimue helping these dissidents who have also been getting assistance from Zaire.

South Africa may now encourage Zaire, with which it has many ties, to resume its policy of aiding various dissident Angolan groups. This would effectively end the whole Western-encouraged movement toward detente between Angola and Zaire.

In any case, the Neto government cannot expect any relief in its war against guerrilla dissidents in southern Angola so long as South Africa maintains a direct or indirect presence in Namibia.