TWO REPORTERS are facing jail in the investigation of the leak of Valerie Plame's identity as a covert CIA operative. Matthew Cooper of Time magazine and Judith Miller of the New York Times have been held in contempt by the respected chief judge of the U.S. District Court in Washington for behavior that countless government sources and whistle-blowers depend on from reporters they talk to. That is, they are honoring promises of confidentiality. Yet unless they prevail on a pending appeal, Ms. Miller -- who never even wrote about the Plame matter -- and Mr. Cooper risk being locked up in an effort to force them to talk.

We don't minimize the investigative needs of special counsel Patrick J. Fitzgerald. While a newspaper's job includes bringing to light important information, there are secrets the government needs to keep, including the identity of covert operatives. The leak of Ms. Plame's status may have been a crime -- though that is not yet clear -- and Mr. Fitzgerald can hardly be faulted for taking his assignment seriously. Still, we hope Mr. Fitzgerald will find a way to avoid further confrontation over what may be loose ends in his investigation.

In any event, his demands are not the only issue the courts should consider. There is also the question of whether reporters should be threatened with jail for doing their jobs. The Supreme Court in 1972 declined to recognize that the First Amendment allowed a reporter to remain silent before a grand jury. But the court's complicated split in the case made the ruling something of a muddle. Relying on the opinion of the justice who cast the decisive vote, lower federal courts since have often acknowledged a privilege not to testify in other contexts. Also, most states have enacted laws to protect a reporter's ability to keep sources confidential in state courts.

What's more, a strong argument remains that notwithstanding the 1972 case, the courts should afford protection under the common law as a discretionary matter. The courts don't force psychologists to testify about conversations with their patients, and they respect the silence of the confessional and the attorney-client privilege. They have decided, in these areas, that protecting professional communications is worth losing certain evidence. The role that journalists play in enabling democratic debate also warrants such protection.

We are an interested party here. In Mr. Fitzgerald's investigation, two Post reporters answered limited questions in their lawyers' offices after their sources gave them the go-ahead. As a newspaper, we are generally troubled by aggressive leak investigations, which rarely bear fruit but may chill legitimate journalism. The point here, however, is not simply the press's institutional interests but the public's interest in the flow of information on important public issues. Leaks can be, and in numerous instances have been, a means by which honest whistle-blowers get the truth out and senior officials disseminate information they are not yet prepared to release officially.

Unfortunately, Mr. Fitzgerald's probe is not an isolated matter. In a civil suit by nuclear scientist Wen Ho Lee over the government's leaking his name as a spy suspect, five reporters have been held in contempt for refusing to name their sources, and a Post reporter has refused to comply with a court's order to reveal his sources. Traditionally, Justice Department guidelines, prosecutorial discretion and court rulings have tended to limit the impact of leak investigations on the press. But the cases in the pipeline -- civil and criminal -- suggest that stronger protections are needed. If the federal courts will not protect the press's ability to honor promises of confidentiality, Congress should establish the privilege, as most states have done. The public will be ill served if information stops flowing because reporters cannot promise their sources confidentiality without risking imprisonment.