Working at the National Archives in the late 1990s, historian William Burr stumbled onto a 1962 telegram written by fabled diplomat George Kennan about China's nuclear program. The telegram, essentially a translation of a Yugoslav newspaper article, was mostly innocuous, but Burr decided to make a copy of it anyway.

It proved to be prescient. Today the original document has been removed from the archive, replaced by a notice that declares it now to be a government secret.

The document is one of 9,500 that have been removed from the archives in a project that has become the new poster child for open government advocates, many of whom contend the Bush administration is taking secrecy to new extremes. Many of the reclassified documents have already been published in government books or still appear on federal Web sites.

"It just seems like a complete overreaction," said Burr, a senior analyst for the National Security Archive. He said it is understandable that the government would respond to the 2001 terrorist attacks, but he added, "Some of this makes little sense because the documents are already in the public domain. It's too late."

Open government advocates say the massive reclassification project carried out by the CIA and other agencies is more evidence for their assertion that this is one of the most secretive administrations in modern history.

President Bush has said he favors open government. In a meeting with newspaper editors a year ago, he said, "I talk to the people in Iraq about a free press and transparency and openness, and I'm mindful we can't talk one way and do another."

But he added, "We're still at war. And that's important for people to realize."

Throughout American history, journalists, librarians and other anti-secrecy crusaders have continually been at odds with presidents over government openness. But many advocates say the Bush presidency has been particularly active in limiting access to government information.

"There has been a pendulum swing far in the direction of increased secrecy," said Steven Aftergood, a senior research analyst at the Federation of American Scientists. "It's not just a matter of a few frustrated reporters. It's also Congress, which has had extraordinary difficulty getting the information it needs.

"It's gotten to the point where it's undermining the effective conduct of American foreign policy."

'Times have changed'

Others say that in an age of terror threats, the greater worry is that critical security information will find its way into the public domain, risking to American lives.

"Times have changed,'' Sen. Pat Roberts, a Kansas Republican who heads the Senate Intelligence Committee, told Fox News Channel after expressing support for legislation that would broaden the scope of criminal charges for leaking classified information.

Historian Matthew Aid reported this year that the CIA and other federal agencies had secretly reclassified more than 55,000 pages of records, including many that have been reproduced in widely disseminated publications.

Aid said some of the now-sealed documents seemed noteworthy only because they were embarrassing. One was a complaint from the CIA about the bad publicity it was receiving over its inability to forecast anti-American riots in Colombia in 1948.

It is common for agencies such as the CIA to review public documents at the National Archives to decide whether they should be reclassified. But the volume and nature of this particular project drew a rebuke from the National Archives and Records Administration, which declared a moratorium this month on further reclassifications.

Allen Weinstein, the chief archivist, asked the agencies involved to "restore to the public shelves as quickly as possible the maximum amount of information consistent with the obligation to protect truly sensitive national security information.''

A CIA spokeswoman said the reclassification effort should be viewed in the context of a massive amount of information -- 26 million pages -- that the CIA has released to the archives since 1998.

Aftergood, who writes a secrecy newsletter for the Federation of American Scientists, said some of the administration's confidentiality initiatives are a legitimate result of the Sept. 11 terror attacks. But he said the White House's anti-openness bent goes well beyond that and started when Bush and Vice President Dick Cheney came to office.

For some journalists, the administration showed its intentions early, when Attorney General John Ashcroft issued revised guidelines for releasing documents under the Freedom of Information Act. The new rules seemed to send a message to federal agencies by declaring that the Justice Department would support any denial of an FOIA request if there was a "sound legal basis'' to do so.

Justice Department officials initially asserted that the revisions would have little practical effect. But a study by the Coalition of Journalists for Open Government found evidence to the contrary, indicating that agency use of exemptions to limit disclosure rose 22 percent from 2000 to 2004.

The big increase in the number of documents ordered classified has also been striking.

Between 1999 and 2004, the number of documents ordered sealed annually nearly doubled, to 15.6 million, according to the Information Security Oversight Office. Meanwhile, the process of making once-secret documents public has slowed -- from 127 million pages declassified in 1999, to 28 million pages in 2004.

Also of concern to journalism organizations is the administration's apparent eagerness to confront reporters who acquire and publish classified national security information. Two separate investigations are under way, involving reporters from the Washington Post and The New York Times, aimed at uncovering who leaked information about terrorist prison sites abroad and the National Security Agency's domestic eavesdropping program.

In recent weeks, the administration has signaled a willingness to play rougher with the news media, suggesting that reporters probably could be charged with a felony simply for coming into contact with classified information even if they did nothing with it.

The White House does not buy the argument that it is depriving the public of crucial information, insisting that tighter secrecy is necessary because of anti-terrorism efforts.

Late last year, with pressure building in Congress to strengthen disclosure laws, Bush issued a surprise order requiring federal agencies to appoint Freedom of Information Act officers and to expedite a backlog of FOIA requests.

"The goal of it is to ... make sure that information is being disclosed in a timely and quick manner," White House spokesman Scott McClellan said.