As Angolan guerrilla leader Jonas Savimbi settled back in his chair at the Capital Hilton's head banquet table last Tuesday to watch the State of the Union address on an oversized television screen, his public relations adviser tapped him on the shoulder and handed him a small index card.

On it were these words of commitment to "freedom fighters" everywhere: "America will support with moral and material assistance your right not just to fight and die for freedom, but to fight and win freedom -- in Afghanistan; Angola; Cambodia and Nicaragua."

They were President Reagan's words -- obtained from a bootlegged copy of the speech earlier in the day -- and when they resonated from the television speakers, setting off a pounding applause in the banquet hall filled with conservative Republicans, Savimbi turned and smiled broadly at the young public relations man, former White House aide Christopher M. Lehman.

It was a climactic moment for both the 51-year-old Savimbi and his counselors at the well-connected lobbying firm, Black, Manafort, Stone & Kelly, which orchestrated -- under a $600,000-a-year contract signed last summer -- a high-profile, high-impact visit to Washington.

The selling of Savimbi began in the African bush last September and included an intricately mapped strategy to woo Congress, the administration and U.S. news media. At his distant guerrilla headquarters in Angola, Savimbi received monthly updates on the shifting political moods in Washington and on the nuances of opinion in the national media. He was meticulously coached on everything from how to answer his critics to how to compliment his patrons.

During his 10-day visit, he had as much exposure on U.S. television networks and in the press as a U.S. presidential candidate. He left Washington Thursday with support from the Reagan administration that appeared virtually monolithic and a private assurance that lethal military aid will be speeding to him within a few weeks.

Savimbi's grand tour through Washington reflected not only the slick packaging of his public relations handlers, however. To the president and the strong conservative movement in the Republican Party, Savimbi's time -- suspended since a 1976 ban on U.S. involvement in Angola -- had come.

By Savimbi's standard, the trip was a big success. It was not, however, unblemished. He was hounded by demonstrators and snubbed by the Congressional Black Caucus for accepting military support from South Africa's white apartheid government. It was also revealed during his visit that two of the three U.S. intelligence agencies contend that Savimbi can't win on the battlefield in Angola against the Marxist government.

Furthermore, and perhaps most disappointing to him, when Savimbi left the country yesterday on a private jet loaned by an unidentified Texas multimillionaire, he failed to carry home a congressional resolution of support, which was seen as a key element in the strategy of his congressional backers and the administration.

As the political crosscurrents in Washington would have it, Savimbi's aid request became ensnared in the mutual suspicions of his conservative Republican supporters and the State Department's Africa bureau, led by Assistant Secretary Chester A. Crocker. At the same time, the administration, seeking an open congressional blessing for its covert aid program, was attempting to bypass hesitant congressional intelligence oversight committees, where some influential members were insisting on a public debate on Angola.

By the end of the week, the principal unresolved Washington policy struggle over Angola was being played out very much behind the scenes: A dozen senators, led by Majority Leader Robert J. Dole (R-Kan.), had warned Secretary of State George P. Shultz that unless he made a concrete commitment to supply Savimbi covertly with the lethal weapons he requested to fight Soviet-built tanks and assault helicopters, they would push to supply such military aid openly.

Despite the snafu on Capitol Hill, it appeared certain that within a few weeks, according to Senate and Pentagon sources, the Central Intelligence Agency and the Pentagon will secretly begin funneling antitank and antiaircraft weaponry of foreign manufacture -- as well as nonlethal items -- to Savimbi's guerrilla organization, the National Union for the Total Independence of Angola (UNITA).

On Thursday evening, in Savimbi's second private meeting with the secretary of state and his African affairs advisers, the rebel leader is thought to have received a pledge that lethal covert aid would arrive at UNITA's camps in southeastern Angola in a matter of weeks. "Shultz is totally on board," one Republican Senate aide said.

More than anything last week, the reemergence of this burly African guerrilla leader struck official Washington with a sense of deja vu. To many liberals, he was the man whose losing cause a decade ago embodied what had gone wrong with the CIA and its never-ending quest to entangle the United States in yet another clandestine war in a distant bushland.

But to conservatives, Savimbi was one of the noble anticommunist heroes abandoned by America during a destructive post-Watergate era of institutional mistrust for the CIA, a period of national introspection and doubt. A number of these conservatives had worked steadily over the years to bring Savimbi back.

Savimbi, a guerrilla since 1966 who once predicted his victory might take until the end of the century, has been patient. In 1977, he told Washington Post reporter Leon Dash that "geopolitics will force [the Americans] to come back to me." Nevertheless, he made futile pilgrimages to Washington in 1979 and 1981, seeking aid after the cutoff 10 years ago.

It was not until mid-1985 that events gave Savimbi a new opportunity to draw attention to his cause. Congressional conservatives scored a sudden victory in July when they won repeal of the Clark amendment, named for then-senator Dick Clark (D-Iowa) who had rallied the Senate against the CIA's clandestine support for UNITA.

This development came atop U.S. frustration over the lack of a negotiated peace in southern Africa and intelligence reports indicating that the 35,000 Cuban and Soviet troops supporting the Angolan army were inflicting heavy casualties on Savimbi's forces.

Prodded by his battlefield losses, Savimbi pursued an idea that had always offended some members of his guerrilla organization: He began shopping for an influential Washington lobbying firm to assist in prying open the aid pipeline from the United States. It did not take long to find help.

Of the three Lehman brothers who have worked in the Reagan administration, Christopher Lehman, 37, is lesser known than his older brother, Navy Secretary John F. Lehman Jr., but both followed similar paths through the national security bureaucracy in Washington. Most recently, Christopher Lehman was a special assistant to the president for national security affairs, lining up support in Congress for the president's defense budgets, arms sales and covert assistance programs to the Nicaraguan counterrevolutionaries, or contras.

On a Friday afternoon last September, Lehman left his White House office for the last time. The following Monday he was on a transatlantic flight with his new boss, Paul Manafort, to a rendezvous in the African bush. The meeting had been set up by Savimbi's Washington outpost. Manafort, a former Reagan campaign aide, hoped to land a new client whose time had come.

The trip was almost aborted when Manafort and Lehman arrived at the meeting place near the Angolan border to find Savimbi locked in a fierce battle to defend his UNITA stronghold at Jamba from combined Angolan and Cuban assault forces. But Savimbi -- considering the battle in Washington of equal importance to the one in the bush -- left his troops for several days of negotiations with Manafort and Lehman.

They returned to Washington a week later with a signed $600,000 contract.

The strategy that emerged from Savimbi's September consultation with his new P.R. counselors was a three-pronged attack in Washington on Congress, the executive branch and the mass media -- to "wake up" America to the plight of the aging Angolan "freedom fighter" facing a better-equipped, Soviet-backed army bent on his extinction.

While Savimbi concentrated on defending his Angolan stronghold, his new Washington advisers, strongly supported by conservative think tanks such as the Heritage Foundation and the American Security Council, began the quiet drive to get Savimbi on the Reagan administration agenda. In meetings at the White House, State Department, CIA and Capitol, they sought statements of support from the president and members of Congress and to pressure the State Department's reluctant African bureau. They also sought to include Angola as one of the "regional conflicts" to be discussed at the November summit talks between Reagan and Soviet leader Mikhail Gorbachev.

A key element of the firm's campaign was to encourage the CIA to reestablish a strong presence in southern Africa. The firm also proposed a covert assistance program for Savimbi that would begin as nonlethal intelligence-sharing and develop into a full-scale weapons supply. In CIA Director William J.Casey, they found a willing ally.

In the news media, the firm encouraged interest in Savimbi and offered CBS News' "60 Minutes" program exclusive access to Savimbi in the bush for a broadcast planned to coincide with Savimbi's trip to the United States.

Savimbi, who has always been an articulate and forceful advocate for his cause, was coached on the strengths and weaknesses of his image here.

But wholly apart from this public relations effort, senior officials in the Reagan administration were conducting a review of Angolan policy. On Oct. 3, CIA Director Casey ordered a special national intelligence estimate on Soviet intentions in Angola. By Oct. 9, according to well-informed sources, a meeting of senior interagency advisers recommended to the president and his National Security Council a covert support program for Savimbi to counter the buildup of Soviet-equipped forces.

President Reagan approved an initial $13 million two-stage covert program on Nov. 12, with nonlethal aid to be followed in a few months by weaponry for Savimbi.

As congressional forces lined up on either side of the issue, Savimbi prepared for his entrance in Washington. At stake was the battle for the "great middle" between the 109 assured votes in the House for aiding Savimbi and the 101 known votes aligned against him.

Savimbi's public relations advisers told him in November that it was no longer a question of whether he would get U.S. assistance, but simply a matter of when, and in what form. During December, one significant public relations coup Savimbi had been waiting for was realized: The president agreed to meet with him in the Oval Office.There also would be an opportunity to meet later with reporters, with the White House as the backdrop.

"The issues of who is Jonas Savimbi and should the United States assist UNITA have now been cast," his public relations counselors told him, adding, "your trip will answer those questions for official Washington and the media."

The whirlwind of appearances, interviews and speeches began on Jan. 29, the day after Savimbi arrived at Dulles International Airport on a private jet.

From the outset, Savimbi was told by key conservatives that the president and his national security advisers already had decided to go forward with a covert assistance program. But he was also told that his performance in front of his critics and supporters would help cement political support to go forward.

According to well-informed sources, Shultz met with Republican Senate leaders at the White House a week before Savimbi's arrival and "took umbrage" that he was perceived to be against providing aid to Savimbi. Shultz told Senate leaders that he preferred a covert assistance program to an open one because of the diplomatic complications that would arise from trying to supply Savimbi through neighboring black African countries, according to these sources.

Shultz also told the Senate Republicans, however, that he needed "an expression of congressional support" to give the administration the political mandate it needed to begin supplying covert assistance to Savimbi as a hedge against potential opposition in the House and Senate intelligence oversight committees.

Under law, the executive branch does not need congressional approval to conduct covert operations through the CIA. But in going forward with a controversial Angola program, the administration runs the risk of another congressional rebellion such as those that led to the Clark amendment in 1976 and the Boland amendment blocking aid to Nicaraguan rebels in 1984.

Shultz's private request of the Republican leadership has been interpreted in congressional circles as an attempt by the Reagan administration to give itself "political coverage."

Senate Majority Leader Dole, according to several sources, took the lead in orchestrating the required political support in Congress. To that end, Dole's staff rewrote -- in close consultation with Savimbi's public relations advisers -- a Senate resolution first introduced last December. The new draft stated: ". . . the president should provide timely assistance critical to UNITA."

Some officials hoped the resolution could be introduced this past week to crown Savimbi's visit. But the resolution ran aground because of concern by Senate conservatives that their efforts could be sidetracked by State's Africa bureau.

On Tuesday, according to one source, the Republican Senate Steering Committee asked Dole to delay his resolution until the CIA had begun providing antitank and antiaircraft weapons to Savimbi. The steering committee staff members feared that once the Senate resolution was passed, the State Department might stall the covert aid program to give more time to negotiators in southern Africa.

This fear was articulated again Wednesday when Dole sponsored a private lunch for Savimbi and about a dozen senators, most of them conservatives, who also expressed mistrust of Shultz's aides in charge of Africa policy: Assistant Secretary Chester Crocker and his deputy, Frank G. Wisner.

These senators asked Dole to again seek a firm assurance from Shultz that once the Senate resolution was passed, the administration would go forward immediately to supply Savimbi with weapons to counter the threat of a Soviet-backed offensive expected in April or May.

Dole and a number of conservative senators conveyed to Shultz on Thursday their reservations about supporting a resolution without a firm administration commitment to back Savimbi, according to well-informed sources. These senators said that without such assurance, they would introduce new measures calling for open military support for Savimbi.

Shultz then met with Savimbi Thursday evening and reaffirmed his commitment to the covert aid program, according to knowledgeable sources. The secretary is expected to give the same assurance to Dole.

With the Senate in recess, Republican sources said Dole will spend the next week lining up a solid majority to give the administration the political cover it seeks to begin the operation. A Senate Foreign Relations Committee hearing is scheduled for Feb. 18 on Dole's resolution and Republican sources said Chairman Richard G. Lugar (R-Ind.) has pledged to work closely with Dole to move the resolution to the floor for a vote.

By the first weeks in March, one confident Savimbi backer said, "It will just be a matter of backing up the forklift in some warehouse, putting the weapons on an airplane and then trucking them in to Savimbi."