THE GOVERNMENT released Hany Mahmoud Kiareldeen last week, following a series of decisions holding that the secret evidence on which he was being detained was unpersuasive and that his confinement was unconstitutional. The government contended that Mr. Kiareldeen, a Palestinian who has lived in this country for nearly 10 years, was a member of a terrorist group, had been peripherally involved in the World Trade Center bombing conspiracy and wanted to kill Attorney General Janet Reno. The Immigration and Naturalization Service had held him since March of last year. Only after seven immigration judges declared the secret evidence unreliable and a U.S. district judge granted Mr. Kiareldeen habeas corpus relief did the government back down.

Mr. Kiareldeen's case is unusual only in degree. The reality is that in a bunch of secret evidence cases during the past few years, the evidence has proven embarrassingly weak or not all that sensitive. For example, an immigration judge initially held that Nasser Ahmed was a national security threat based on the government's secret showing. But when the government released some of the evidence against Mr. Ahmed in response to a subsequent lawsuit, Mr. Ahmed was able to rebut the evidence sufficiently to convince the same judge that he had erred. Yet Mr. Ahmed, who has been held more than three years for allegedly being a member of an Islamic fundamentalist terrorist group, remains behind bars while the government appeals.

When the government sought to use secret evidence to kick out six Iraqis brought to this country by the CIA following the collapse of an American-backed Iraqi opposition base, the defense could not even get a summary of the material. Later the government admitted the material had been erroneously classified. In another case, the government arrested and sought to deport eight Los Angeles activists for the Popular Front for the Liberation of Palestine on the basis of secret evidence. But when it suited the government's purposes to use that evidence in open court in the litigation that followed, it did so.

The reality is that the use of secret evidence is antithetical to the premises of our judicial system. It is easy to imagine cases in which an alien poses a genuine national security threat yet the disclosure of the evidence against him would threaten national security as well. But the answer cannot simply be to permit procedures that are unfair and likely to yield inaccurate findings. There is a reason defense lawyers are a part of our judicial system.