JAMES B. CONKLING, the new director of the Voice of America, has chosen a strange way to enhance the stature and authority of the United States' principal instrument for telling the world about itself. The occasion arose when a memo from one of his new aides came to light last week. Written by Philip Nicolaides, VOA coordinator for commentary and news analysis, the memo urged turning the Voice into "a propaganda agency" that would sell America the way an advertising agency sells soap.

The disclosure of the memo, in the context of an ongoing discussion of how VOA's parent organization, the International Communication Agency, should gear up to serve the Reagan foreign policy, provided Mr. Conkling with an important test. He could find Mr. Nicolaides another job at ICA, thus laying to rest the wholly damaging impression that the Voice is to be converted into a Soviet-style propaganda organ. Or he could retain Mr. Nicolaides, thus telling the world, which listens to this sort of thing, that there is something to that impression after all. It is a matter of record that Mr. Conkling chose to keep Mr. Nicolaides on--not for his policy recommendations, Mr. Conkling insists, but for his talents as a "creative writer."

It's a pity. In the minds of many people, the Voice will now be laboring under the presumption that it is engaged in selling "the sizzle not the steak," to use one of Mr. Nicolaides' more creative applications. How odd that evidently neither Mr. Nicolaides nor Mr. Conkling could comprehend that Mr. Nicolaides was bound to become the "sizzle" as far as the VOA's image is concerned, regardless of what the "steak" of its broadcasts turns out to be.

And that's a pity, too. There has not been a good public debate for some years over the way the United States' overseas broadcasts ought to be harnessed to its international interests. It is not at all out of the question that the Carter-era emphasis on objectivity of news broadcasts, and the deeper assumptions of global cultural compatibility, did in fact produce "mush" on some occasions--to borrow another of Mr. Nicolaides' creative formulations. ("Mush," we note, like "propaganda," is finally in the ear of the hearer.) But for the Voice to entrust responsibility for its commentary and news analysis to the likes of Mr. Nicolaides can only confuse the search for a soundly based information policy. Surely the Voice of America can run a credible, hard-hitting foreign braodcast program wihout imitating Radio Moscow.