MORE THAN 30 YEARS AGO, when I lugged some books on Palestine into a New York city room to prepare for a foreign assignment, my managing editor growled, "I don't want any goddam expert on this job. If you can understand it, not knowing anything about it, maybe you can make readers understand it. Now get those books out of here."

My managing editor, by no means a clown, was enunciating one of the popular theories at the time of how foreign news should be covered: Send out an ignorant reporter to inform an ignorant public. I still marvel at how many competent newspapermen believed it.

Mort Rosenblum, in reporting on the state of the art, writes that we have made progress since then, but not much. In accounting for the appalling ignorance of most Americans about foreign affairs, he comments: "Correspondents and editors who might do a better job are reinforced by their misguided rule of thumb: 'All anyone cares about is coups and earthquakes.'"

Although he uses the cliche as the title of his lively and sometimes hilarious new book, Rosenblum cares deeply about a lot more and suggests methods for improving the public's awareness of issues that could become critical to the nation's survival.

He is well qualified both to make the diagnosis and to offer a prescription for change. Since 1967, he has been working abroad as a reporter and war correspondent for the Associated Press and, after serving as head of the AP'S Paris bureau, recently became editor of the fabled International Herald Tribune in Paris.

What bothers Rosenblum chiefly about foreign correspondence today is the weakness of the system -- the dependence on a relatively few men and a scattering of women, reinforced by a usually ill-paid and uncertain army of part-time reporters called "stringers," to cover the world. He uses an Ohio University figure of 430 full-time correspondents for U.S. news organizations abroad, which I'd put even lower on the basis of my own running census. In any case, there certainly are fewer foreign correspondents serving America today than at any time since the 2,500 who were at work at the end of World War II.

Nor is the use of foreign news much better in the American news media. On the basis of interviews with numerous editors and broadcasters while on a fellowship for the Council on Foreign Relations, Rosenblum estimates that many average-sized newspapers publish less than 1,000 words a day of foreign news, discarding most of the 100,000 furnished by the news agencies and syndicates.

Sometimes it's worse than that. I remember an editor, who was chairman of a committee surveying the use of foreign news, admitting cheerfully that his own paper used less than a half-column a day. "We're a local paper," he said without apology, "and we print local news."

In consequence, Rosenblum writes, most Americans get their foreign news mainly from television -- and he rates electronic news as the least effective of all because of its sparseness and distortions.

That is the serious side of Coups and Earthquakes ; But like all foreign correspondents who have written about the art, he pokes fun at his fellow-correspondents, his editors, the lordly "specials" who write heavyweight pieces for the papers and, of course, himself. Reading much of the book is like sitting in a dingy barroom, somewhere in a far-off town that has suddenly been thrust into world attention, and listening to a dozen correspondents making irreverent remarks about almost everybody and everything in their particular bailiwick.

One of my favorite Rosenblums -- he tells a fine story -- is the one about a television stringer who phoned her network editor about the return of Eva Peron's body to Argentina 23 years after her death. "They're bringing back Eva Peron," she telephoned. The response: "See if you can get an interview with her in English."

For those who think such Rosenblums are exaggerated, I offer my own favorite experience, an exchange of messages over the independence of Indonesia and my identification of Sukarno as the first president. "NEED FIRST NAME SUKARNO." "HAS NO REPEAT NO FIRST NAME.: "NAME HIM ACHMED. MUST HAVE FIRST NAME."

The shortcomings of Rosenblum's book are the shortcomings of the work of any good wire service reporter -- and he was first-rate. He covers too much in too brief a space and, inevitably, some of his work is sketchy. For example, he sums up foreign news on television and radio in 15 pages, censorship and government pressures in 16, reporting today's wars in 13 and foreigners' view of what we report about their countries in only four pages. phowever, he makes some good points, in a comparably brief space, about economic reporting and the coverage of human rights issues, so the condensation isn't always regrettable.

Like some of today's editors who handle staffs of foreign correspondents (there aren't many of these editorial paragons), Rosenblum believes that no major reforms are needed, that better reporting, better writing and a public more actively committed to international affairs could solve the major problems of the art. But at least one editor makes a point that a lot of foreign correspondents don't want to hear: "There is nothing written in stone that says news has to come from a staff correspondent." He is for using professors, businessmen and others (and I wish him luck in editing their copy).

While there is much in Rosenblum's book to give warning of the consequences of an ill-informed public served by so vulnerable a system of foreign news reporting, a lot of it can make a journalist proud of his profession, too. When one reads of the exploits of some of the best -- Peter Arnett of the Associated Press, the now retired Homer Bigart of The New York Times , Jim Hoagland of The Washington Post and Jack Foisie of The Los Angeles Times -- there is a fresh realization that there are always a few men and women abroad -- as there have been in the past -- who can in emergencies rise above the frailties of the system and tell the story as it must be told. That is still our hope for the future.