Jonas Malheiro Savimbi, 43, stood up dressed in a pressed camouflage uniform with a green silk Ascot, the red beret pulled jauntily to the right matching the reddish gloss on his cordovan-colored boots.

"The country is living a moment of decision," his baritone voice boomed out to the 530 delegates at the UNITA congress, "and that is why you are here. To make decisions that will free our country from Soviet imperialism."

The delegates jumped to their feet and cheered wildly for five minutes.

Stately and imperious, his left hand on his hip, he waited for the cheering to end. Seemingly, it did not matter what he said just as long as Savimbi spoke - telling them what to do, how to do it and how long it would take. They would follow.

Savimbi, the founder of UNITA, has been its leader - not without challenge - since 1965. He is also the lifeblood of the UNITA guerrillas' fight against Angola's Soviet- and Cuban-supported government. Without him, it is questionable if they could continue.

"In African society it is the chief who leads the people," said UNITA guerrilla Capt. Jaka Jamba. "Savimbi is the chief, "if he were killed, I don't know what would happen to UNITA."

Savimbi is an enigma, a man on whom many labels can stick - brilliant, charismatic, affable, unyielding, forgiving, temporizing, Machiavellian, opportunistic, lying, nationalistic, Marxist, Maoist, pro-Western and socialist. He speaks Portuguese, French, English and several Angolan languages.

He is a member of Angola's largest tribe, the Ovimbundu. There has been at least one attempt, in 1968, to assassinate Savimbi - by two Ovimbundu within the ranks of UNITA. On another occasion, a top UNITA leader of the Chokwe tribe tried to get his fellow Chokwes to overthrow Savimbi as UNITA's leader on false charges of tribalism.

Savimbi forgave all three men.Two of them are still in leadership positions within UNITA today. "He says he is a Marxist," guerrilla Maj. Mateus Katalyo said about Savimbi, "but he is a Christian."

Although Savimbi is seen by the outside world as a tribal leader, in point of fact his charisma does cross tribal lines and extends far beyond the Ovimbundu.

Although he claims to be an African nationalist, Savimbi lost his standing as a legitmate African leader in the eyes of most of Africa's leaders by collaborating with the South African armed forces at the height of the Angolan civil war.

Savimbi claims he was a victim of circumstances, "When the South Africans invaded Angola they dictated terms to me," he told me.

"We were too weak militarily to fight the government forces and their Cuban allies," he said. "We could not fight the South Africans, too. That would have been a ridiculous position."

Savimbi lied, denying that the South Africans were in Angola for 2 1/2 months after they had invaded. Reliable Western intelligence sources said that Savimbi invited the invasion, meeting with the South Africans in Runtu, Namibia, in early September 1975 - a full month before the invasion.

Savimbi's dual political personality is also evident in the countries from which he managed to secure arms for his guerrillas - 5,000 World War II American carbines from the Central Intelligence Agency and 500 Soviet AK-47 Kalashnikov assualt rifles from Romania.

"I was willing to take arms from anywhere," he said, "I made a mistake as far as the Americans were concerned. Our friends told us they would back us and they sent us old carbines . . . no good for this type of war. The soldiers use them for hunting food." Savimbi uses the expression "our friends" as aeuphemism for the CIA.

"We thought Angola was of such interest to the West that they would stop the Russians." Savimbi continued, "We were mistaken and left in the cold.I now understand that the American government will help us if they see it as being in their strategic interests. I would not be surprised to see them recognize the [Popular Movement] government."

His experience with the CIA has not embittered him, Savimbi said. "I do not get frustrated with blows or conceited with victory," he said. "It does not help to have hatred or resentment. They are two bad emotions that will cut off the light to think clearly."

Savimbi said he favors a mixed economy of capitalism and socialism and described himself as a "moderate" socialist: "Nationalization would not be my ultimate nor immediate aim. Foreign companies will not bring the technical know-how to Angola without something in return. You must be honest with the company, however, and tell them that the wealth will be returned to the country."

Savimbi rejected the idea of seeking a reconciliation with Agostinho Neto, Angola's Marxist president, sputtering:

"Neto needs to reconcile himself with the nation and stop being a black Portugese. He thinks Angola is where he is living in his palace in Luanda," Angola's capital. "He has never been in the shantytowns. He thinks Angola is downtown Luanda.

"We can think about making a reconciliation only when the Cubans and Russians are gone. Not before. No. Never.

"Neto said he is going to teach Marxist-Leninism in primary school here. He is a fanatic, a European colonizer. To bring Russian law here is another type of colonization, Marx must be kept in his place. We should take from Marx only that which applies to our situation."

Savimbi's UNITA guerrillas will continue to fight against the Cuban and Soviet-supported government for the indefinite future, he said.

"The Cuban will not leave here because of pressure from America or anyone else. They will leave here because Neto lied to them and told them he was the most popular. The Cubans are dying, so they now know that is not true. And if Castro leaves them here too long, they will become counter-revolutionaires when they return home," Savimbi said.

"The Russians mean business in Angola, and so do we. The Cubans are only the Russians' lackeys," he said.

"The Russians think they will expand throughout the South African subcontinent, but no one in the West will sacrifice South Africa. Not France, not Britain, not the American Republicans, not the American Democrats.

"None of them will sacrifice South Africa. Geopolitics will force them to come back to me."