African states try new tactics for Namibia independence.

Namibia's future comes before the United Nations Security Council next week as part of a new strategy by some African nations to win independence for the embattled territory.

About 30 foreign ministers from third-world countries as well as from European countries are expected to address the council and vent their frustration at the lack of progress on implementing Security Council Resolution 435, which calls for a cease-fire, deployment of UN forces and observers, and UN-supervised elections in Namibia.

While the session may begin with a bang, it may end with a whimper.

The ''front-line'' states of Angola, Zambia, Botswana, Zimbabwe, Mozambique, and Tanzania, in addition to the South-West Africa People's Organization (SWAPO) , are reportedly not eager to ask for sanctions against South Africa at this point. Rather, the group seeks to have Resolution 435 reaffirmed and to have no linkage between South Africa's putting an end to its illegal occupation of Namibia and the withdrawal of Cuban troops from Angola.

The African strategy, according to well-placed sources, aims at moving the question of Namibia to the council in three stages.

Next week's meeting will seek a new commitment by the council to Resolution 435. Another meeting in early September will propose the gathering of a new Geneva conference (the last one, which collapsed, was held in December 1980) with the front-line states, the ''contact group'' (United States, Canada, France , West Germany, and Britain), SWAPO, and South Africa talking to each other indirectly.

Should South Africa refuse to attend such a conference, a third council meeting toward the end of the year might then call for economic sanctions of one kind or another against South Africa.

In a report on the question of Namibia which he will present to the council, UN Secretary General Perez de Cuellar notes that while on the one hand the contact group was able to elaborate and fine tune the UN plan for the Namibia's independence and to get the front-line states as well as South Africa to agree with its provisions, on the other hand the introduction of a ''foreign element'' (not pertaining to Resolution 435), namely the linkage between Namibia's independence and the withdrawal of Cuban troops from Angola, has halted the implementation of the UN plan in its tracks.

South Africa and the US informed Angola a year ago that it would not be possible to let Namibia achieve its independence as long as an estimated 25,000 Cuban troops stationed in Angola are not withdrawn. ''This is not unreasonable as we see it,'' says a US diplomat.

Angola has rejected the linkage between Namibia's independence and the presence of Cuban troops in its territory. However, it has been engaged in a twin set of high-level bilateral talks with South Africa and with the US in an effort to explore ways toward a comprehensive agreement by which the concerns of all the interested parties might be addressed. Theoretically, as described by a Western source, a package being presented entails:

* The simultaneous and gradual withdrawal of Cuban troops from Angola and the withdrawal of South African forces from Namibia as Namibia moves toward independence.

* Angola's regime broadening its base by admitting some leaders of UNITA (a South-African-backed rebel group operating in southern Angola under the leadership of Jonas Savimbi).

* A tighter rein held by Angola over SWAPO, which presumably would lessen SWAPO's role in a future Namibian government.

* South Africa's economic aid to Angola for its reconstruction and the US establishing diplomatic relations with Angola.

Whether the Angolan leadership will accept the US-South African offers and ''cut itself loose from its Soviet and Cuban friends in order to become pro-Western,'' as one Western diplomat puts it, is open to question.

US diplomats are tight-lipped on the matter. But according to one US source, no progress was made at the 11th round of the Angolan-US talks which took place in Washington last month. Angola sent Lt. Col. Manuel Alexandre Eduardo Rodrigues, minister of the interior and No. 2 in Luanda's regime, to Washington where he met with Vice-President George Bush and with Secretary of State George Shultz. The talks were ''friendly'' but ''led to no breakthrough,'' according to West European officials on the basis of information given them by the US.

Angola insists that the Cubans are essential to Angola's security. If the Cubans are to be sent home, South Africa and the US must give ironclad assurances to Angola regarding its security. ''Pious assurances will not be sufficient, that much is clear. And on the other hand, how can the US concretely guarantee Angola against further South African raids into its territory? And how can the US guarantee that it will not seek to replace the present Angolan leadership with a more pro-Western one in the future?'' says a diplomat deeply involved in the ''Namibian question.''

The fact that Namibia's new administrator general, Willie van Niekerk, is trying to reactivate Namibia's internal parties with a view toward an election, is interpreted by the front-line states as a sign that South Africa is not really interested in an early settlement on Namibia's independence. Nevertheless , Angolan separate talks with South Africa and with the US are expected to continue.