In an experiment popularly known as "General Botha's Junta," the 20-month-old administration of Prime Minister Pieter W. Botha has greatly increased the influence of the South African military establishment in day-to-day decisions of government.

At the heart of Botha's overall policy is the use of the military as a power base to implement limited socio-economic reforms against rightist civilian opposition, often from within Botha's own National Party, while totally marshaling the country's institutions for an inevitable conflict.

Not incidentally, Botha's plan has acquired a military vocabulary: it is described as a "total strategy" to win what is perceived as the outside world's "total war" against South Africa's white minority government.

Closely associated with this plan is Botha's handpicked defense chief, Gen. Magnus Andre de Merindol Malan, with whom Botha had a close working relationship since serving as defense minister under former prime minister John Vorster. When Botha succeeded Vorster, he kept his portfolio as defense minister, and brought Malan with him into the decision making spheres of the government.

By doing so, Botha wedded the most powerful military machine south of the Sahara to the administration, strategic planning and policy making of a regime that by its own admission is fighting for survival against the internal challenge of its disenfranchised black majority and the military threat of its black African neighbors.

"Why do you think Botha kept the defense portfolio?" asked one influential member of the secret society of Afrikaner men, the Broederbond, and a man who helps shape Botha's policies. "It was not because he thought he was the best-ever defense minister. It was in order to make reforms.

"The structural changes, to the extent [of those] we in South Africa have to make, have never in history been done in a democratic manner," he said.

While right-wing whites complain that the Army is "forcing integration" down their throats, many other whites think Botha's rule approximates an "enlightened dictatorship" that is giving pragmatism an edge over ideology in the government's approach to race relations and maintenance of white rule.

"Nobody's complaining much because it's bringing in reforms," said one observer.

But opponents of the government's racial policies believe the ascendancy of the military has ushered in the "politics of control" in which social and economic changes, and the political consequences that will flow from them, will be carefully paced and regulated so as not to endanger state security.

For them, Malan struck an ominous note three years ago in a newspaper interview when he referred to the "conflicting demands of a total strategy and democratic system." The critics expect little sunshine to filter into the dark recesses of South African civil liberties, as shown by the military's recent request for a near total blackout on press reporting of security matters.

The military's promotion of a program of reforms is a tactic to stave off war, observers here say.

"They adhere to the American West Point view of guerrilla war that fighting it is a matter of 'winning hearts and minds'," said South African political analyst David Willers.

"Top generals believe that separate develpment [apartheid] is still workable.Soweto needs tarred roads, bathtubs and electric, they say. They think in term of basic human needs. But they don't think of political rights so the blacks can bargain for these amenities," said one Afrikaner academic close to the military.

"Don't forget, the military is made up of Afrikaners, white South Africans. They are not working for majority rule. They are working to avert it," said one white newspaper editor.

"The military wants the government to have a plan -- we are doing our 20 percent by defending the borders, now you do your 80 percent, they say to the politicians," said Piet Cillie, Afrikaner professor of journalism at Stellenbosch University.

Botha is giving them a plan that calls for drawing every sector of society -- industry, business, the press, universities, the military -- into a government-directed effort to build up a moderate consensus of all races for gradual, limited change in South Africa.

One of the first explanations of "total strategy" came from Malan three years ago in a local newspaper -- before Botha was prime minister. "In a mature state the fundamental concepts of conflict entail far more than war," he said.

"It means the formulation of national objectives in which all the community's resources are mustered and managed on a coordinated level to ensure survival. Every activity of the state must be seen and understood as a function of total war."

Coordination is the rationale behind Botha's recent appointment of a board of industrial leaders to advise the military on defense planning. Afrikaner historian Hermann Giliomee cited this as one example of South Africa's "emerging military - industrial complex," similar in some respects to that of Brazil.

The vehicle for the coordination of the military's veiws with those from other departments is the State Security Council.This is a statutory body that was dormant under Vorster but now meets every two weeks as part of Botha's extensive reorganization of government administration.

The council has become the government's main think tank, taking over a function that used to belong to the broederbond alone. In many ways it is already an alternate cabinet by virtue of decisions it makes.

The government refuses to officially acknowledge the council's full membership, but Malan is there by law. Two military men. Lt. Gen. Andre Van Deventer and retired Brigadier John Huyser, formerly of military intelligence, head the secretariat, which prepares staff papers for the council's meetings and executes its decisions. The secretariat is reportedly heavily staffed with military aides.

The military prefers voluntary cooperatin with "total strategy" to coercion. To encourage cooperation the military constantly emphasized the dangers facing South Africa, almost fostering a war psychology. A speech by a military official without mention of the "Marxist onslaught" is a rare event. Top civil servants get lectures on "total strategy" in courses at the military college in Pretoria.

"We are in the midst of this total war at this moment," Malan said three years ago, "and as long as we are nt fighting back we are losing."

The military has also tried to set an example of the new racial attitudes necessary to create the multiracial consensus that is at the core of "total strategy" by recruiting from all races and integrating some military facilities.

The tandem governing of Botha and the military has been at the expense of Botha's National Party, fractured and emasculated by the military-backed reform program and revamping of government administration.

"Right now, the military sees its role as preventing violent change so that peaceful change can take place," said opposition defense spokesman Harry Schwarz. "It's a holding operation until reforms can work."