In a world hungry for news, it runs the Voice of America. In a time of emerging third-world interests, it oversees several respected academic exchange programs.
In a period of strained US-Soviet relations, it corrects propaganda and ''disinformation'' about the United States.
But in an age of austerity, it is shrinking.
Like other federal agencies, the United States International Communication Agency (USICA) has been hit by the 12 percent cuts announced by President Reagan Sept. 24.
But in the process of cutting, the agency has stirred up nationwide controversy - which surfaced last week with the revelation of an internal memo by a high-ranking Voice official redefining the radio service as ''a propaganda agency'' rather than (as its charter specifies) a source of ''accurate, objective, and comprehensive'' news.
Behind that memo, however, is a broad shift in emphasis that has led the USICA smack into three major policy debates over: what to trim in the USICA, whether the US should fund defense hardware at the expense of the dissemination of ideas, and whether Voice broadcasts should be unbiased or propaganda. Debaters are arguing:
1. Which of its two major areas - the broadcasting services of the Voice, or operations like the Fulbright program, which exchange students and scholars with other nations - is best able to tell the world what America stands for?
As the agency trims its budget by an additional $67.4 million, one or the other has to be cut. The latest budget recommendations from the USICA itself place the burden squarely on the exchange programs. As detailed in the agency's own ''impact statement'' last month, $44.4 million will come out of the educational exchanges, and only $1.8 million from the Voice.
The rationale, according to the agency, is that the ''staff intensive'' Voice would be permanently damaged by the cuts, whereas exchange programs can be deferred and later rebuilt.
The results: the Fulbright fellowship program, which since 1946 has sent 45, 000 Americans overseas and brought in 85,000 foreign students, will remain active in only 59 of its present 120 countries.
And cuts in the International Visitor Program, which has helped bring some 33 current heads of state and 600 present cabinet ministers for extended visits to the US in what the USICA statement calls ''formative stages of their careers,'' will decrease the annual number of foreign visitors from 1,500 to 750.
The proposed cuts would also terminate the Humphrey fellowships program, which currently provides training in public-service fields to 106 foreign nationals. Also to be cut: support services for the 300,000 foreign students currently in the US.
So far, the threatened cuts have provoked outcries from university presidents , scholars, and educational associations around the nation.
2. As America moves to strengthen its defenses, should its money go only to military hardware and manpower, or should it also go to the dissemination of ideas?
Critics of the cuts point out that the US is already far behind both its allies and its enemies in spreading good news about itself. In the last 15 years, the agency's funds have decreased by 30 percent in constant dollars. A report last May by a coalition of major US exchange organizations (some of which administer the Fulbright and Humphrey programs) found that ''Procter and Gamble's annual advertising budget is larger than the (budget for the) USICA's information activities.''
The USICA statement notes that the Soviets spend an estimated $2 billion annually, more than four times the USICA budget of under $500 million.
Much of that money is for academic study. The Soviets, for example, annually offer 24,000 grants to African nationals to study in the USSR, while the US offers only about 2,000 such places. A report of the House Committee on International Relations in 1977 found that ''in Soviet-third world cultural relationships the Soviet leadership appears to have placed its greatest hopes for ultimate success in the academic exchange programs.''
3. Should the agency try to provide unbiased and neutral news coverage, or should it advertise American values and specifically counter Soviet propaganda?
On this point, a decision has apparently been made. Charles Z. Wick, the new director of the USICA, is steaming ahead with ''Project Truth.'' As a counter-propaganda campaign designed to supply diplomatic posts around the world with quick replies to false news reports, it began a monthly publication, ''Soviet Propaganda Alert,'' on Oct. 15.
Meanwhile, the Voice of America, which reaches an estimated 67 million people weekly in 39 languages, has come under heavy criticism for failing to reflect administration policy. The Voice has recently been blasted by the US Embassy in Moscow for airing excerpts of an American television interview with a Soviet spokesman, Georgi Arbatov.
It has also been reprimanded for broadcasting reports in the US press saying that the Central Intelligence Agency was supplying arms to Afghan guerrillas. And earlier this month, following rumors that personnel changes would be made for ideological reasons, two senior Voice officials were replaced. Most recently , Voice staffers in disagreement with the shift in emphasis circulated a petition calling for the removal of Philip Nicolaides, whose leaked memo has caused such consternation.
Pressure on the USICA to conform to government dictates is cyclical, say those familiar with its history - rising in intensity as detente gives way to cold-war attitudes. ''It is to be expected, given the climate of the times,'' says executive officer Grant Hammond of the Center for International Affairs at Harvard. He finds the present shift in emphasis ''reminiscent of the more strident rhetoric of the '50s and '60s.''
Yet the outcry over the proposed cuts in exchange programs has been fueled in part by the agency's own statements - leading to speculation that the USICA is purposely offering provocative cuts and hoping that public opinion will lead the administration to relent.
Other critics of the cuts note that strong USICA programs are crucial to the Reagan administration's interest in economic self-sufficiency for the third world. ''Without good solid education,'' says Dr. Richard Krasnow of the Institute of International Education, ''economic development in the third world is not going to happen.''