It has been more than a year since that modern American morality play, The Ugly American, hit the scene with its less than surprising revelations about State Department boobery abroad. Whatever its literary drawbacks--and they were great--the book did arouse public interest in an important field.

But now, as President Eisenhower prepares to set out on his gala 13-nation trip, many months after The Ugly American appeared, the United States still has an ambassador in Paris who speaks German, no French, and an ambassador in Bonn who speaks French, no German. In addition, American embassies throughout the world are dotted with the rankest collection of amateurs that any diplomatic corps can boast.

Soviet ambassadors, as The Ugly American pointed out, are career officials, carefully and intensively trained in the language, history and sociology of the nations to which they are assigned. By contrast, the United States has traditionally used such irrelevant standards as the size of campaign contributions and long-time political service on the home front in selecting its diplomats. The result is a hit-or-miss system that occasionally succeeds, but more often ends up in quiet failure or conspicuous disaster.

The highly publicized Brooklyn dress manufacturer who didn't know the name of the premier of Ceylon and the German-speaking Ambassador to France are all too typical of American amateur diplomats. Such men are needed, in the cases of Paris, London and other Western European capitals, because a career man cannot afford the huge expenditures of an embassy social season; they are used in other cases because the United States has not awakened to the importance in international relations of normal diplomatic channels and a competent man on the spot.

There are, of course, lucky exceptons: Douglas Dillon and David K. E. Bruce are examples of amateurs who became outstanding professionals. But the rule generally holds: in many important nations American ambassadors have little diplomatic experience, little knowledge of the native language and customs; in short, little qualification for their jobs.

The solution obviously is to create a strong career diplomatic corps and to draw ambassadors from this group. A larger appropriation for social expenses could solve the problem of finances in the major capitals of Europe.

In any event, when Mr. Eisenhower visits his 13 capitals next month, he will not find the same kind of qualified, experienced diplomat that greeted Mr. Khrushchev on his similar travels a few years ago. The Ugly American may have been the hero of the book, but in the form of the amateur ambassador, he is currently the villain of American diplomacy.