R. VALICENTI / J. POBOJEWSKI

WASHINGTON - Can the United States government still keep a secret? In an age of WikiLeaks, flash drives and instant Web postings, leaks have begun to seem unstoppable.

That may be a first impression. Sobered officials are scrambling to stop the hemorrhage of documents, even as antisecrecy radicals are discovering that some secrets may be worth protecting after all.

Still, there’s been a change. Traditional journalism, which has long accepted leaked information bit by bit, has been joined by a new counterculture of information vigilantism that promises disclosures by the terabyte.

That accounts for how, in the three big WikiLeaks document dumps since July, the usual trickle of leaks became a torrent. All of it, disguised as a Lady Gaga CD, was smuggled out of a military intelligence office, according to prosecutors, by Private First Class Bradley Manning, an American soldier now imprisoned and charged with the leak.

Two decades ago, in the days of kilobytes and floppy discs, such an ocean of data would have been far more difficult to capture and carry away. Four decades ago, using a photocopier, a leaker might have needed a great many reams of paper and a tractor-trailer.

“I do think it’s true that the large contours of national and international policy are much harder to keep secret today,” said Steven Aftergood, who runs the Project on Government Secrecy at the Federation of American Scientists, an organization in Washington that promotes transparent government. “It would not be possible to conduct a secret war in Cambodia, as took place in the Nixon administration.”

Indeed, within hours of American missile strikes in Yemen against suspected Al Qaeda camps last December, amateur video of the destruction was on YouTube. The videos labeled the strikes “American.” The strikes have never been publicly acknowledged by the Defense Department.

Or consider the speed at which news travels. During the Iran-contra affair, American arms sales to Iran were first reported by a Beirut weekly, Al Shiraa, in November 1986; it was a few days before the American press picked up the story. “Now it would take a few minutes,” said Mr. Aftergood.

One unexpected development in the Obama administration has been four prosecutions of government employees on charges of disclosing classified information, more such prosecutions than under any previous president.

That is a reason to suspect that the openness of this new era will have limits. Would-be leakers can, presumably, be dissuaded; they can be outmaneuvered in the technological cat-and-mouse game; they can learn self-restraint. And there are signs that all of that may be happening.

Thomas S. Blanton, director of the National Security Archive at The George Washington University in Washington, which obtains and publishes declassified government documents, said that WikiLeaks “tried to create a safe place for disclosures. But with Bradley Manning behind bars, who’s going to rush to follow his example?”

Now, with the third WikiLeaks collection linked to Private Manning in the news, members of the United States Congress have called with new ferocity for punishing the group and its provocateur-in-chief, Julian Assange, a 39-year-old Australian citizen who has been granted bail in Britain on sex charges from Sweden. He will be monitored by the police and will not be allowed to travel abroad.

The Obama administration is determined to to preserve its secrets. The Defense Department is scaling back information sharing, which its leaders believe went too far after information hoarding was blamed for the failure to detect the September 11 plot.

The department has also stripped CD and DVD recorders from its computers; it is redesigning security systems to require two people, not one, to move large amounts of information from a classified computer to an unclassified one; and it is installing software to detect downloads of unusual size.

Yet even as the government seeks to rein in WikiLeaks, WikiLeaks is reining in itself. The confidential diplomatic cables it disclosed have unquestionably turned the discreet world of diplomacy upside down. But the disclosures have been far more modest than WikiLeaks’ self-proclaimed dedication to total transparency might suggest.

Had it chosen to do so, WikiLeaks could have posted on the Web all 251,287 confidential diplomatic cables about six months ago, when the group obtained them. Instead, it shared the cables with traditional news organizations . So far, fewer than 1 percent of the cables had been released on the Web by the antisecrecy group, The Times and four European publications combined.

“They’ve actually embraced” the mainstream media, “which they used to treat as a cuss word,” Mr. Blanton said. “I’m watching WikiLeaks grow up. What they’re doing with these diplomatic documents so far is very responsible.”

When the newspapers have redacted cables to protect diplomats’ sources, WikiLeaks has generally been careful to follow suit. Its volunteers now accept that not all government secrets are illegitimate; for example, revealing the identities of Chinese dissidents, Russian journalists or Iranian activists who had talked to American diplomats might subject them to prison or worse.

But WikiLeaks has not quite joined the ranks of traditional publishing.

Mr. Assange has created what he calls an “insurance” plan . The group has put on the Web encrypted files containing a huge trove of documents that have not yet been released. Thousands of people have downloaded the files.

If the United States moves to prosecute, Mr. Assange has said, the group will release the encryption key, in effect making public tens of thousands of unredacted cables - and who knows what other dangerous secrets.

It is a 21st-century threat, and one the Obama administration is taking very seriously.


SCOTT SHANE ESSAY