A few days after the Oct. 25, 1983, invasion of Grenada, U.S. Information Agency Director Charles Z. Wick returned from Europe and told Alvin Snyder, head of his television and film service: "We're getting clobbered in Western Europe. Our best allies are really down on us about Grenada. We've got to do something fast to get our message across."

Eight days later, U.N. Ambassador Jeane J. Kirkpatrick and the leaders of two Caribbean countries that supported the U.S. intervention held a satellite news conference with European journalists in five major West European capitals.

It was a major step in the evolution of a little-noticed aspect of President Reagan's approach to dealing with other countries. Over the past five years, the former actor who built a political reputation as "the great communicator" has transformed the government's lackluster foreign information activities into the largest and most technologically adroit propaganda apparatus in the world.

"We were gambling on an experiment that we'd talked about a lot, but we had no real idea of how it would work," Snyder said of the hastily arranged Kirkpatrick news conference. "After we were only a few minutes into it, though, you could sense we had something. I remember Wick leaning over to me in the control booth and saying, 'Al, we're on a roll. Keep that satellite up.' "

The two-hour, trans-Atlantic exchange resulted in front-page headlines throughout Europe and was widely credited by U.S. diplomats with helping to blunt criticism of the Grenada incursion. It also marked the debut of the globe-girdling satellite television network, WORLDNET.

WORLDNET has become what some USIA officials privately call "the jewel in the crown" of the administration's fascination with the aggressive propaganda techniques that the administration calls "public diplomacy" and that Reagan describes as "telling the message of American democracy to the world." Reaganomics has meant shrinking budgets for most of the federal bureaucracy, but USIA's funds have almost doubled.

When Reagan took office in 1981, the annual USIA budget was slightly less than $458 million. This year the agency's budget is $837 million. The White House, in contrast to its proposed cuts of most other agencies, has asked Congress to boost USIA's fiscal 1987 funding to $959 million.

These hefty increases have stirred concern about whether the administration is using the money to promote its hard-line, anticommunist views or to create a propaganda ministry.

Many of the Wick-era initiatives clearly have had rightist overtones, including Project Truth, a campaign to counter Soviet disinformation; a companion "semantic corruption" drive against communist misuses of such words as "liberation" and "peace"; the production of "Let Poland be Poland," an expensive television attempt to focus attention on the Polish people's plight under the communist crackdown, and pursuit of Reagan's Project Democracy to give financial aid to groups seeking to foster democracy in other countries.

But while these undertakings have attracted a lot of publicity, they are only a small part of what has been happening at USIA under Wick's stewardship.

By far the largest share of the money that the administration has pumped into public diplomacy has gone for technological improvements, bolstering of long-standing programs and experimentation with new ways of communicating ideas.

Most of the funds have gone into a $1.3 billion to $1.8 billion multiyear modernization of the Voice of America to replace antiquated equipment and build new transmission and relay sites. This program is aimed at expanding the VOA's ability to reach areas such as central Russia and to avoid jamming behind the Iron Curtain.

Large sums also have gone to such ventures as the creation of Radio Marti, a separate radio network under VOA direction that beams daily broadcasts to Cuba; increasing by 200,000 a year the number of American books put into foreign circulation; a new system to teach English to foreigners, and an Artistic Ambassadors program that selects a number of talented young American musicians to tour other countries, giving concerts and conducting classes.

But of all these projects, WORLDNET perhaps best illustrates the mix of "global village" technology, glossy packaging and sky's-the-limit thinking that Wick and other savvy media operators have brought to the task of putting the administration into the forefront of international propaganda efforts.

During the past 2 1/2 years, through WORLDNET the U.S. government has been able to reach 30 countries to stage news conferences with such top officials as Secretary of State George P. Shultz and Defense Secretary Caspar W. Weinberger, to show foreign audiences live coverage of a congressional hearing, and to help American scientists and scholars talk with their colleagues in other lands.

When the leaders of several African countries threatened to boycott the 1984 Olympic Games in Los Angeles, some were induced to change their minds after WORLDNET let them exchange views with Peter Ueberroth, organizer of the games, and Tom Bradley, the black mayor of Los Angeles.

Since last April, WORLDNET also has been transmitting two hours of regular programming each weekday to Western Europe, where cable TV systems make it available to more than 3.2 million European households and hotels. Viewers get a half-hour of news and a variety of other fare ranging from cultural programs to Washington sportscaster George Michael's "Sports Machine."

Similar daily programming in Spanish and Portuguese is scheduled to begin this spring to Latin America. And by late this year, USIA says it hopes to begin additional regional WORLDNET services to the Middle East, East Asia and Africa.

"The only problem with WORLDNET is that it's ahead of its time. The facilities don't yet exist in other countries to make full use of its potential," said Leonard Marks, who headed USIA under President Lyndon B. Johnson in the 1960s. "But it's the wave of the future. It's what all major countries someday will be using to tell their stories, and it's the United States that's showing them the way."

In addition to USIA, the administration's propaganda weapons include the Board for International Broadcasting, which since 1974 has administered the two "surrogate" radio operations established by the Central Intelligence Agency in the early 1950s: Radio Liberty, which broadcasts to the Soviet Union, and Radio Free Europe, aimed at Moscow's East European satellites.

But it is USIA, with its more wide-ranging functions, that is the center of the administration's web of propaganda activities. That has made Wick the most influential USIA director since the late Edward R. Murrow during the Kennedy administration.

Unlike the suave and sophisticated Murrow, Wick -- a former lawyer, nursing home owner, band leader, movie producer and real estate investor -- has the personal style of a rough-edged, lone-wolf Hollywood deal maker. He begins a newspaper interview by telling the reporter, "I have to say that a lot of the stuff that's been written about me in the press was pretty scurrilous." Then he adds deadpan: "Why, some of it wasn't even true."

His fondness for one-liners has not interferred with his ability to translate his friendship with the first family into funding support once undreamed of in his traditionally cash-starved agency. Moreover, even people who disagree with his politics or dislike him personally concede that Wick understands the art of communication and has a natural instinct for innovation.

House Foreign Affairs Committee Chairman Dante B. Fascell (D-Fla.), who has watched the USIA closely over the years, says: "Despite some overzealous rhetoric and some mistakes in his method of operation, Wick has done an extremely effective job of modernizing the agency beams daily broadcasts to Cuba; increasing by 200,000 a year the number of American books put into foreign circulation; a new system to teach English to foreigners, and an Artistic Ambassadors program that selects a number of talented young American musicians to tour other countries, giving concerts and conducting classes.

But of all these projects, WORLDNET perhaps best illustrates the mix of "global village" technology, glossy packaging and sky's-the-limit thinking that Wick and other savvy media operators have brought to the task of putting the administration into the forefront of international propaganda efforts.

During the past 2 1/2 years, through WORLDNET the U.S. government has been able to reach 30 countries to stage news conferences with such top officials as Secretary of State George P. Shultz and Defense Secretary Caspar W. Weinberger, to show foreign audiences live coverage of a congressional hearing, and to help American scientists and scholars talk with their colleagues in other lands.

When the leaders of several African countries threatened to boycott the 1984 Olympic Games in Los Angeles, some were induced to change their minds after WORLDNET let them exchange views with Peter Ueberroth, organizer of the games, and Tom Bradley, the black mayor of Los Angeles.

Since last April, WORLDNET also has been transmitting two hours of regular programming each weekday to Western Europe, where cable TV systems make it available to more than 3.2 million European households and hotels. Viewers get a half-hour of news and a variety of other fare ranging from cultural programs to Washington sportscaster George Michael's "Sports Machine."

Similar daily programming in Spanish and Portuguese is scheduled to begin this spring to Latin America. And by late this year, USIA says it hopes to begin additional regional WORLDNET services to the Middle East, East Asia and Africa.

"The only problem with WORLDNET is that it's ahead of its time. The facilities don't yet exist in other countries to make full use of its potential," said Leonard Marks, who headed USIA under President Lyndon B. Johnson in the 1960s. "But it's the wave of the future. It's what all major countries someday will be using to tell their stories, and it's the United States that's showing them the way."

In addition to USIA, the administration's propaganda weapons include the Board for International Broadcasting, which since 1974 has administered the two "surrogate" radio operations established by the Central Intelligence Agency in the early 1950s: Radio Liberty, which broadcasts to the Soviet Union, and Radio Free Europe, aimed at Moscow's East European satellites.

But it is USIA, with its more wide-ranging functions, that is the center of the administration's web of propaganda activities. That has made Wick the most influential USIA director since the late Edward R. Murrow during the Kennedy administration.

Unlike the suave and sophisticated Murrow, Wick -- a former lawyer, nursing home owner, band leader, movie producer and real estate investor -- has the personal style of a rough-edged, lone-wolf Hollywood deal maker. He begins a newspaper interview by telling the reporter, "I have to say that a lot of the stuff that's been written about me in the press was pretty scurrilous." Then he adds deadpan: "Why, some of it wasn't even true."

His fondness for one-liners has not interferred with his ability to translate his friendship with the first family into funding support once undreamed of in his traditionally cash-starved agency. Moreover, even people who disagree with his politics or dislike him personally concede that Wick understands the art of communication and has a natural instinct for innovation.

House Foreign Affairs Committee Chairman Dante B. Fascell (D-Fla.), who has watched the USIA closely over the years, says: "Despite some overzealous rhetoric and some mistakes in his method of operation, Wick has done an extremely effective job of modernizing the agency . . . . No one has been more innovative and imaginative in waging the war of ideas."

Such praise hasn't been heard too often at an agency that long was scorned by the professional diplomats of the State Department and kept on a tight leash by Congress. Its charter, which stresses that the agency's mission is to inform people in other countries about the United States, has created innumerable internal conflicts over the years about what USIA could or couldn't do in furthering that goal.

"Under the Carter administration, for example, there was a tendency to deny the idea that USIA should advocate anything at all," recalled Stanton H. Burnett, a career officer who now oversees USIA programs as counselor of the agency. "The feeling was that we should function as a semi-news agency and a semi-entertainment agency but that in the realm of ideas we should be no more than a conveyor belt for every stripe of opinion."

Wick, while conceding there has been "something of a pendulum swing" away from that approach, insisted that his guiding principle at USIA "is to tell the world about America in all its diversity. It's simply not true that I came aboard as the chief apostle of a right-wing takeover and the chief subverting agent of a conspiracy to bend USIA and the Voice of America to our philosophy. There may be people who wanted to do that, but Congress has made it very clear that that's against the rules."

But he added, "Telling about America means telling people about America's foreign policy. Right now that policy is set by Ronald Reagan, and if we're going to tell the story accurately, we have to make clear what President Reagan believes in and what his policies stand for. There may be people who don't like those policies, but that doesn't lessen our responsibility to explain them with forthright journalistic accuracy."

At the moment, Wick's attention is focused primarily on following up his January trip to Moscow, where he discussed plans for the cultural exchanges agreed to by Reagan and Soviet leader Mikhail Gorbachev at the Geneva summit last November.

The agreements, the only concrete result of the summit, call for reviving a series of U.S.-Soviet exchanges that were suspended after the 1979 Soviet invasion of Afghanistan. Reagan also proposed a new program of people-to-people exchanges financed on the U.S. side by private sector contributions.

At present, they are the only initiatives showing promise of progress in the drive to improve U.S.-Soviet relations, and USIA has the responsibility for implementing them.