"The reporter’s constitutional right to a confidential relationship with his source stems from the broad societal interest in a full and free flow of information to the public. It is this basic concern that underlies the Constitution’s protection of a free press, … because the guarantee is not for the benefit of the press so much as for the benefit of all of us."

Those sentiments, written by Justice Potter Stewart in 1972, in Branzburg v. Hayes, are at the heart of the "reporters’ privilege" about which copious quantities of ink may soon be spilled. It appears increasingly possible that columnist Robert D. Novak and perhaps several other journalists may be subpoenaed in the potentially explosive criminal investigation into suspected White House leaks of a covert CIA agent’s name.

Justice Department prosecutors have already questioned at least four White House officials before their grand jury and have interviewed at least five others, including Karl Rove, President Bush’s top political adviser, and I. Lewis "Scooter" Libby, Vice President Cheney’s top aide. According to some news reports, investigators seem to be laying the groundwork to question reporters if they can’t crack the case by other means.

And unfortunately for any subpoenaed journalists — and their sources — Justice Stewart’s argument for a broad First Amendment reporters’ privilege came in a dissenting opinion. Although subpoenas of reporters are extremely rare, the widespread notion that they have a broad First Amendment privilege not to testify rests on shaky legal foundations, at least in the context of criminal investigations.

In his opinion for the 5-4 Branzburg majority, Justice Byron R. White — whose disdain for the news media was legendary — came close to holding that, in criminal grand jury investigations, no special reporters’ privilege exists: "We are asked to [interpret] the First Amendment to grant newsmen a testimonial privilege that other citizens do not enjoy. This we decline to do…. We cannot accept the argument that the public interest in possible future news about crime from undisclosed, unverified sources must take precedence over the public interest in pursuing and prosecuting those crimes reported to the press by informants."

The justice who cast the deciding vote, Lewis F. Powell Jr., qualified White’s holding by saying in a concurrence that courts should block demands that reporters disclose confidential sources unless investigators have a "legitimate need" for the information. And many lower courts have held that reporters’ interests in protecting sources may in some cases outweigh litigants’ need for disclosure. But most of those cases have been civil lawsuits. In the current case, in which the reporters were firsthand witnesses to the possibly criminal acts being investigated, the odds are strong that the courts would reject any claims of privilege, order the reporters to name their sources, and jail them for contempt if they refused.

The biggest obstacle to any subpoenas of Novak or other reporters is a long-standing Justice Department regulation severely limiting prosecutorial efforts to demand information from the news media. It requires, among other things, that the information sought be essential to the investigation of a crime; that all other methods of obtaining it first be exhausted; and that any subpoena be approved at the highest level of the department.

But these protections are not judicially enforceable. They are grounded less in law than in politics — specifically, the power of the news media to hurl a withering barrage of hostile publicity at the Justice Department if it subpoenas a prominent journalist. The media’s self-interested approach to such issues may explain the remarkably muted reaction to a February 10 Washington Post report that several White House officials have refused requests by prosecutors that they sign waivers releasing reporters from any promises of confidentiality to their sources in this case. The waiver forms reportedly request "that no member of the news media assert any privilege or refuse to answer any questions from federal law enforcement authorities on my behalf or for my benefit."

Why haven’t the media — which have long clamored for Bush to order his aides to cooperate fully with prosecutors — made a stink about his apparent failure to order them to sign these waivers? The answer seems to be that the media understand that such waivers would increase the pressure on them to disclose their sources.

But a subpoena of Novak might not provoke as large an eruption of media outrage as would occur if, say, Katie Couric, or Dan Rather, were ordered to identify a source who had leaked classified information to expose high-level wrongdoing. The reason is not merely that some of Novak’s more liberal colleagues — who long ago dubbed the annoyingly smart, famously acerbic conservative "the prince of darkness" — might enjoy seeing him hauled away in handcuffs. It is mainly that in this case, the leakers are not whistle-blowers pursued by powerful officials. They are powerful officials seeking to discredit, or spite, a whistle-blower — and in the process, perhaps, recklessly endangering CIA sources overseas.

Citing such considerations, Geneva Overholser wrote a February 6 New York Times op-ed calling upon Novak to make an exception to the "cardinal rule" that journalists should never burn their sources; he should "acknowledge his abuse of confidentiality" — and in so doing, burn his sources. Would Overholser have said the same if this were a Democratic administration? I wonder. In any event, this investigation is heating up at a time when Bush’s credibility is already under attack on issues ranging from his claims that Saddam Hussein had weapons of mass destruction to his lowball estimates of the costs of his new Medicare prescription drug entitlement.

The many reporters who see the Bush White House as a den of dissemblers smell blood in the water. And Washington is seething with speculation that the suspects may include Rove, Libby, or perhaps other top officials.

The investigation grew out of the White House campaign last summer to discredit retired diplomat Joseph C. Wilson IV. He had drawn White House wrath by publicly challenging President Bush’s January 28, 2003, assertion that Britain "has learned that Saddam Hussein recently sought significant quantities of uranium from Africa." Wilson said that he had found such reports to be false when the CIA sent him to Niger in February 2002 to investigate. A few days after Wilson went public last July, Novak published a column that quoted claims by "two senior administration officials" that Valerie Plame, "an agency operative on weapons of mass destruction," had suggested her husband for the mission to Niger. This and subsequent disclosures to other reporters may have been designed to imply that Wilson was unqualified for the assignment — or, worse, to retaliate against him.

A 1982 law makes it a felony to name a covert intelligence agent with knowledge that her identity is classified and that she has worked undercover abroad during the past five years. Most intelligence analysts’ identities are not secret. But Plame’s had reportedly remained classified — until it was leaked to Novak — to protect contacts from her past and possible future undercover work abroad. It is far from clear that the leakers knew enough about Plame’s status to make the leaks criminal. But even if they did not, they would presumably be prosecuted if caught lying to investigators, and fired if identified.

The Justice Department investigators — headed since Attorney General John Ashcroft recused himself in December by Patrick J. Fitzgerald, the U.S. attorney in Chicago — appear for now to be doing everything possible to uncover the sources of the Plame leaks short of demanding testimony from journalists. If and when they end up deciding that such testimony is essential, the subpoenas may start flying. And the journalists on the receiving end will be in an extremely difficult position.

Were I one of them, I would decline Overholser’s advice to burn my sources. Even if they were powerful officials with base motivations, I would feel bound by what happens to be a cardinal principle of morality as well as of journalism: A promise is a promise. I would prefer to stay in the nicer sort of jail, and not for very long. But I would not expect much help from the courts.

I would, instead, be hoping for my source to do the honorable thing by taking me off the hook before I had to figure out exactly how much jail time a promise is worth. I would also be hoping for sustained media pressure on the administration to let me go, and find some other way to police its own officials. A more forceful effort by Bush to get his staff to come clean would be a good start.