THE DECISION by the Department of Justice to drop criminal charges against an official of the International Telephone and Telegraph Company forcefully raises a question to which we have -- to be quite frank about it -- no clear answer. It is whether the judicial system is sufficiently sophisticated to protect government secrets from needless exposure in a criminal trial that must be conducted in public. The Justice Department thinks not, at least insofar as the case of Robert Berrellez is concerned. The department concluded that the public interest would be better served by dropping the perjury charges against him than by running the risk that secrets supposedly involving national security would be exposed if the case went to trial.

That cannot have been an easy decision to reach. Mr. Berrellez was accused of lying to a Senate subcommittee and the political pressure to prosecute him has been heavy. Nor is it an easy decision to second-guess since the secrets the government chose to protect are known only to it, Mr. Berrellez and his lawyer. They may be matters that would merely embarrass the government if they became publicly known, as some members of the Senate assert, or they may be matters that the government has a legitimate need to keep secret.

Our concern is not with the wisdom of the decision in this particular case, although we have no reason to doubt the good faith of the Department of Justice, but with the weakness in the legal process it has exposed. The same weakness hangs over some pending cases, including those involving former leaders of the Federal Bureau of Investigation, and over many espionage cases. It raises the possibiliity that some government officials or others who know a great deal about intelligence operations can commit certain crimes without fear of punishment.

The problem in the Berrellez case is illustrative. As part of his defense, Mr. Berrellez apparently intended to use information involving secret CIA relationships in Latin America. He claimed that information was essential to his defense, but the Justice Department said it was not relevant. Under normal judicial procedure, the question of relevancy would be decided as the trial progressed. But the government wanted to know, in advance, what secrets would be exposed if the trial went on and to eliminate the possibility that some of them might pop out in public testimony before their relevancy was decided. It asked for a non-public, pre-trial hearing at which it would learn which secrets Mr. Berrellez intended to reveal and which of these the judge would permit into evidence. When the courts rejected that request, the government dropped the case.

This is not the first prosecution abandoned because secrets might become public, and it will not be the last. Usually that has happened when the secrets were an essential part of the case -- material, for instance, that the defendant was said to have stolen -- and the government had to choose between exposure and prosecution. In those cases, the government has to make that choice because there is no provision in American law -- and there should not be one -- for keeping secret any part of the evidence actually used at a criminal trial. But the government is in a quite different situation in a case like this one in which the secrets may be irrelevant and where its real fear is that they will be exposed needlessly or accidentally.

From its perspective, the Justice Department's proposal for a closed hearing made sense; it would have known after the hearing exactly which secrets, if any, would have become known during the trial and could have weighed that loss against the value of the prosecution. But closed hearings are not something to be undertaken lightly in view of the Constitution's requirement that criminal trials be conducted in public. The conflict between competing constitutional values is clear. The courts themselves have so far seemed unwilling to try to resolve it. Perhaps Congress should at least examine the possibility of drawing up some sort of legislative guidelines for those rare instances when the government has a compelling reason to protect legitimate secrets from needless exposure. Maybe no procedures can be established in advance that would not compromise the principle of an open judicial process. But if that is so, then society must be prepared to accept the alternative -- that some defendants will continue to be albe to escape trial by threatening to reveal secrets that have no valid role in the case against them.