South Africa has created a controversy by proclaiming a unilateral plan for drafting a new interim constitution for the disputed territory of Namibia.

The action is being seen by some observers critical of the South African government as evidence that it might seek new pretexts for delaying a Namibian settlement if the United States achieves a pullout of Cuban troops from Angola. The presence of Cuban forces in Angola, which borders Namibia, has been regarded as the last remaining obstacle in reaching an agreement under which South Africa would surrender control of the territory.

In interviews this week, senior South African government officials denied that the proposal for a new constitution is designed to put off a settlement, insisting that South Africa's plans did not cut across the efforts of the United States-led contact group of Western nations to arrange a settlement for the Namibia question. South Africa has been under international pressure, including several U.N. Security Council resolutions, to give up its mandate which was originally conveyed by the old League of Nations.

The officials said that there was no thought of trying to draft an independence constitution but merely a new interim one for administering Namibia more effectively until it becomes independent.

The United States appears to be taking the view that provided the South African move does not impinge on any of the subject areas under negotiation, it should be treated as a nonevent.

However, there is clearly some concern about what Angola and the other African states with whom the contact group must negotiate think of South Africa's intentions.

"We are not thrilled about it," one U.S. diplomat confessed, "but I do not think it necessarily means there has been any change of intention on South Africa's part."

The proclamation dealing with the plan for the constitution was issued Monday by Willem van Niekerk, South Africa's administrator general in Namibia. It empowers him to name 50 members from the territory's 40-odd political parties to a state council.

The council is to draw up proposals for an interim constitution, which will be put to a referendum in Namibia. There is, however, no commitment to implement the constitution if the voters endorse it.

The proclamation specifies only that the referendum result will be placed before the administrator general to help him decide on a formula for running the territory until independence.

Some observers wonder about the point of going to all the trouble and expense of drafting an interim constitution, putting it to a referendum and then presumably holding a general election after it has been implemented, unless there is a reasonable expectation that it will be in effect for several years.

"It is a pointless exercise if you are expecting a settlement and makes sense only if you are not," said John Kirkpatrick, a Windhoek politician who has been involved in the contact group's negotiations from the outset.

Others like Kenneth Abrahams, editor of the Namibian Review and one of the territory's shrewdest politicians, see the state council as a device for stalling.

Abrahams thinks the South African government wants the settlement delayed to give it time to recover from the deep divisions over Prime Minister Pieter W. Botha's domestic reform proposals now racking the Afrikaner community, before having to face the potentially even more divisive issue of a withdrawal from Namibia.

This would be particularly damaging for Botha if, as likely, the South-West African People's Organization (SWAPO) wins the preindependence elections which are the object of the negotiations. The organization has been waging a guerrilla war to wrest Namibia from South African control.

Many observers here agree with Abrahams' assessment on this and think Botha is trying to stall. At the moment U.S. support for South Africa's insistence on a prior withdrawal of Cuban troops from Angola is providing the delay, but should this be removed they think Botha will come up with some other delaying tactic.

In the meantime, having dissolved Namibia's national assembly last January because he felt it was not developing into a strong enough opposition to take on SWAPO, Botha faces the problem of how to keep the parties active and alive during such a delay.

This, says Abrahams, is where the state council comes in. "It is to give them something to do so that they don't atrophy to the point where they cannot oppose SWAPO if ever unsupervised elections are held," he suggests.

There are some political analysts here who think the decision to start drafting an internal constitution may indicate a more fundamental shift by South Africa than just a desire for temporary delay.

They see indications, also noted by Britain's Economist magazine in a special report last week, that South African foreign policy has entered a more aggressive phase while the negotiations have been in progress.

The new strategy, it is being suggested, is for South Africa to use its military and economic muscle as a regional superpower to bludgeon its black neighbors into a more pliant attitude toward it.

Subscribers to this theory are asking whether South Africa has not decided that a settlement in Namibia is incompatible with the new strategy, since it creates an image of retreat rather than one of indomitable command of the whole region.

As South African officials describe it, their motives are clear and should leave no room for misunderstanding. The government still genuinely wants a settlement, they say, and stands by its pledges to the Western contact group.

The decision to set up the state council is a purely internal matter to meet internal needs and does not cut across the international negotiations in any way, several senior officials said in interviews.

"It is in all sincerity not an alternative to an international settlement," said van Niekerk's chief aide, Sean Cleary, from Windhoek. "It is a constructive use of the time while we await developments."

Cleary felt it would not be a pointless exercise even if an international agreement were reached soon. It would give Namibia's political leaders valuable experience in addressing the issues that would have to be faced when the time came to thrash out agreement on an independence constitution.

Another senior official contended that frustration caused by the prolonged negotiations had brought the territory close to a political and administrative breakdown that required urgent attention.

"Whatever the state of the negotiations, we have to do something to stop the place falling apart," he said.

When van Niekerk first floated the idea of a state council in March, he purportedly had in mind a broad-based elected body that could become more representative and popular than the recently dissolved national assembly, and thus the nucleus of a future electoral alliance strong enough to compete with SWAPO.

He soon ran into resistance, however, from the frustrated and increasingly cantankerous parties.

Now he has settled for a nominated body that is expected to be shunned by many of the important parties. Only the 11-party Democratic Alliance of Dirk Mudge, which Botha has already labeled a failure, the white National Party and five minor ethnic parties have agreed to participate.