For the past several decades, there has been an informal understanding between the reporters who uncovered newsworthy secrets and the government intelligence agencies, which tried to keep them from public view.

We would tell senior officials what we'd learned. And they would point out any unforeseen consequences that might arise from publication, such as the death of an American informant. Ultimately, the call on what appeared rested with editors. But it was a decision informed by more than our own guesswork.

The release of more than 75,000 classified documents by WikiLeaks this week makes that arrangement seem as quaint as vinyl records and typewriters. Julian Assange, the organization's leader and avowed opponent of the war in Afghanistan, told Amy Goodman, host of the radio program Democracy Now, that he saw no reason for reporters to take such precautions. (Update: Democracy Now is also broadcast on TV.)

"We don't see, in the case of a story where an organization has engaged in some kind of abusive conduct and that story is being revealed, that it has a right to know the story before the public, a right to know the story before the victims, because we know that what happens in practice is that that is just extra lead time to spin the story," Assange told Democracy Now.

The New York Times, one of three global news organizations given early access to the documents, followed its customary practice, and before it published anything approached the administration for comment. Bill Keller, the paper's executive editor, told me in an e-mail that the White House ultimately answered three of its questions in writing. He said those statements were also provided to The Guardian of Britain and Der Spiegal of Germany, the other two publications.

According to Keller, the White House also asked The Times to pass a message to WikiLeaks requesting that it withhold from release anything "that would endanger lives."

"We pointed out that we were doubtful of our leverage with WikiLeaks," Keller wrote. "But we did pass the message on."

Wikileaks has said it is reviewing an additional 15,000 documents subject to what it described as "a harm minimization process demanded by our source." It said "these reports will be released, with occasional redactions, and eventually, in full, as the security situation in Afghanistan permits."

Several publications pointed out Thursday that the 75,000 documents WikiLeaks has already put online makes it possible to identify Afghans who have cooperated with Western forces. The New York Times reported it had found "dozens" of instances in which informants, potential defectors and others could be unmasked.

It is entirely possible that some of these people will be killed as a result of the publication of these once-secret documents. In Iraq and Afghanistan, even the suspicion of collaboration with American forces has triggered executions.

It has always been difficult to find a balance between the demands of security and robust journalism. Senior intelligence officials were never comfortable with the notion that the press had a right to overrule their judgment of what should be kept secret. For their part, reporters worried that officials would exaggerate the dangers of publication to block embarrassing stories.

When I was a national security reporter, I agreed several times to delay publication of a story or omit certain details. Once, I delayed an article disclosing that Jordanian intelligence had planted an operative inside a Palestinian terrorist group.

Earlier this month, The Washington Post agreed to withhold certain details from a searchable database that included the locations of thousands of facilities performing top secret work. "One government body objected to certain data points on the site and explained why; we removed those items," the Post told its readers, adding that it did not heed the complaints of another agency that "objected that the entire Web site could pose a national security risk but declined to offer specific comments."

The ferment over WikiLeaks brings the government and journalists closer to confronting a question neither side really wants to join: Is there anything more society could do, or should do, to prevent the release of properly secret information?

Suspicions have been deepened whenever the government declassified large quantities of documents and it became clear that the "secret" stamp was frequently wielded to conceal mistakes and misconduct, not information sensitive to national security.

There have been some notable clashes between the press and government over secrecy. In 2005, The New York Times brushed aside protests from the Bush administration and revealed that the National Security Agency had been intercepting communications involving American citizens without court approval. The Bush administration argued that the program was legal and an essential weapon in the war on terrorism. Times editors pushed ahead, even after being told they would have "blood" on their hands if there were another terrorism attack against Americans. Public reaction to the Times revelation ranged from praise for uncovering the program to suggestions that Times editors be tried for treason.

Ultimately, the administration did nothing.

The issue of how the press should handle nationally significant government documents was joined in the 1971 Pentagon Papers case when the Nixon administration attempted to prevent The Times and Washington Post from continuing publication of a secret history of the Vietnam war. By a 6-3 vote, the Supreme Court held that such prior restraint violated the First Amendment.

But four justices raised the possibility that courts could apply a 1950 provision of the Espionage Act that, while it didn't call for blocking publication in advance, made news organizations criminally liable for publishing secrets derived from communications intercepts or code-breaking. This law, passed at the outset of the Cold War, is routinely violated but has never been enforced. It is notable because it focuses on publication. Every other part of the Espionage Act, which originally passed in 1917, focuses on punishing the individuals who pass "information relating to the national defense," to a "foreign government."

It was clear to me in my years covering national security for The New York Times (1985-1990) that neither side really wanted to test the constitutionality of this statute. A significant percentage of the government's classified documents include material derived from eavesdropping by the National Security Agency. The Bush administration could easily have charged the Times with a criminal violation in 2005 over its revelations about an NSA eavesdropping program; it chose not to do so.

The WikiLeaks episode illustrates how much has changed in just a few years. Government officials hoping to leak classified material once had to make contact with a reporter, build trust and physically carry documents out of their offices to a safe location. An editor would then study the material and decide whether it was newsworthy.

Now, the aspiring leaker need only find a way to bypass the government's security procedures and zip an e-mail to a secure server. As the Washington Post series documents, the number of people with security clearances is exploding. Future leaks are inevitable.

It does not appear that many of the Afghanistan war documents posted this week derive from electronic intercepts. But someday soon, something will find its way on the Web that precisely fits the 1950 act. At that moment, whoever is president will face some very uncomfortable choices.