Although American officials and experts are convinced that an American correspondent in Moscow has been charged with espionage primarily to apply leverage for obtaining the release of an Russian being held on spying charges in New York, the choice of a journalist as the pawn seemed to these experts to serve a second purpose as well.

They said the spying charge against the correspondent, Nicholas S. Daniloff of U.S. News & World Report, sent a message of warning about correspondents who befriend Soviet citizens, a message that has been delivered periodically during the post-Stalin era.

At the foundation of this message is the powerful discomfort of Soviet authorities over reporters' relationships with ordinary Russians, who can provide richer portraits of Soviet life than officials ever do.

Through the years, the K.G.B. has repeatedly tried to frighten both correspondents and Russians away from these relationships, especially when the correspondents have been fluent in Russian and have acquired many friends, as in the case of Mr. Daniloff, who was charged with spying today.Slashed Tires a Signal

Various techniques have been used to pass this message. Correspondents have sometimes emerged from the apartments of Soviet dissidents to find the tires of their cars slashed. From time to time, an attractive Soviet woman may try to pick up a traveling reporter, presumably to get him into a compromising situation.

In 1978, Soviet television filed a libel suit against two correspondents -Craig R. Whitney, now an assistant managing editor of The New York Times, and Harold D. Piper, now editor of the Op-Ed page of The Baltimore Sun - for...