In the West African nation of the Congo, bookstore browsers can choose from a rich assortment of inexpensive, Soviet-produced books. Standard works of Russian political literature sell for the equivalent of 25 cents, or even a dime. Basic USSR economic textbooks sell, at most, for $2.
But an American economics textbook - if available at all - costs at least $20 , says Robert Murphy, chief of the United States Information Agency's (USIA) library division.
''In the Congo, I was appalled at the ease of access to Soviet (books),'' says Mr. Murphy, who recently returned from a tour of duty in that country. ''Many of our own (books) were simply not available.''
President Franklin Delano Roosevelt once said that ''books are bullets in the battle for men's minds.'' If that's true, the US - despite its nuclear arsenal - is venturing into the world poorly armed.
Since the beginning of the 1970s, US commercial book exports have stagnated. Large, private book-distribution organizations, such as the renowned Franklin Book Program, have disappeared.
In 1965, the USIA's book-publishing program printed 12.5 million volumes for shipment overseas. Last year the number was 600,000. By way of comparison, in 1979 the Soviets produced 87 million copies of translated books, though a portion of those were for domestic use.
''I think it's a crisis situation,'' says John Cole, executive director of the Library of Congress's Center for the Book.
Mr. Cole swivels in his chair. Outside his office window, the low dome and cupola of the main Library of Congress building shimmer in the damp Washington heat. ''After all,'' he says, ''books are the most effective way of transmitting ideas.''
The US itself is testimony to that fact. The Founding Fathers, while hammering together the structure of the United States government, were heavily influenced by the books of foreign political philosophers such as David Hume and Francis Hutcheson (both Scots), and the Swiss Jean-Jacques Burlamaqui.
Yet today the classic works of US political theory often are not available in other countries - even for NATO allies. The Italian edition of The Federalist papers, for instance, has been out of print for many years.
And, as the rough draft of a Library of Congress study points out, US books can serve more than the simple propaganda purpose of disseminating US political thought and culture. Textbooks and technical journals are badly needed by developing nations. The export of US-published books can help third-world countries develop their resources, and ensures that English will remain the primary language of technical and scientific communication, the report says.
''The demand for American books is tremendous,'' claims Donald McNeil, chief of USIA's book programs division.
Yet book exports of US commercial publishers are essentially stagnant, having increased only 0.8 percent since 1974. Exchange-rate troubles, the comparatively high prices of US books, and the difficulty of distributing small quantities of printed material in foreign lands have kept book exports flat, while US foreign trade in general has boomed.
Government-sponsored book programs have fallen on even harder times. The number of USIA's foreign libraries has dropped from 182 in 1963 to 131 today. The Information Guarantee Program, a massive government effort to disseminate US printed matter abroad, was a colossal flop in the late '60s. ''Ladder Editions, '' American classics written in simple language for foreign students of English, were highly popular, yet expired from lack of funds in 1975.
Meanwhile, the Soviets are flooding the third world with cheaply priced books. In 1981 the USSR produced 12.5 million copies of Spanish-language books alone, US government officials claim.
But as the success of several private philanthropies shows, there are ways to overcome the numerous obstacles to increasing the flow of US books abroad.
During its 25 years of existence, the Franklin Book Program, a nonprofit organization that scraped by on grants and foreign government contracts, translated more than 3,000 US titles into such languages as Farsi, Urdu, Bengali , and Malay. Franklin's chronic lack of funds finally caught up with it in 1979.
The Asia Foundation's ''Books for Asia'' program, on the other hand, is still going strong. ''We're having the best and biggest years in our history,'' says Richard Lamb, the program's director.
''Books for Asia'' distributes overstocked books donated by US publishers to 22 Asian countries. That old standby, Paul A. Samuelson's ''Economics,'' is a particular favorite, Asia Foundation officials say.
''Almost all basic business and economics texts are highly desired,'' Mr. Lamb says.
Last fall, USIA director Charles Wick called for more emphasis on book distribution overseas. His Project Democracy initiative - deleted from the budget by Congress - included $5 million for translating the basic US political classics into standard Romance-language editions.