Before the 9/11 terrorist attacks on the United States, the public had access to declassified documents concerning U.S. policy that were housed in the National Archives in Washington. But at some point over the past few years, many of these documents have disappeared from the Archives' shelves, because the government decided to make them secret again.  This development has historians and others worried about a trend toward secrecy in the name of national security.

Until 2001, anyone could walk into the National Archives in Washington and read, for example, how the United States badly miscalculated China's intervention in the Korean War in 1950.  They could also read a 1958 government plan for responding to a nuclear attack on the United States.

Not anymore. The government's efforts to make public documents secret again accelerated in the wake of the September 11th, 2001, attacks on the United States. 

Since then, historians say, nearly 10,000 documents, totaling more than 55,000 pages, have been reclassified, and removed from public access. Many of the missing documents contain references to the Korean War, the Cold War between the Soviet Union and the United States, nuclear proliferation and the 1962 Cuban Missile Crisis. They say other documents simply contain information that the government might find embarrassing.

Critics of the reclassification program say the Central Intelligence Agency (CIA) and other U.S. spy agencies are the driving force behind the move to reclassify the documents. A CIA spokeswoman disputes that the agency is trying to keep information from the public, telling VOA that it works closely with the National Archives and has released 26 million pages of declassified documents to the Archives since 1998. The spokeswoman added that the CIA is "committed to the highest quality process" for deciding what should be kept secret.

The government's move to make secret again information about events that took place as much as 50 years ago and no longer have an impact on national security is troubling to historians, journalists and legislators.

Republican Party Congressman Christopher Shays of Connecticut, questions what the point is of making documents secret again that have, in many cases, already been published elsewhere.

"I think it is somewhat stupid, because once it is out, it is out," he said.

At the heart of the reclassification debate is the question of whether government can be truly open and accountable, when it suppresses the public's right to know.

Joan Bertin is the executive director of the National Coalition Against Censorship. She says the more people know about their government, the better they will be governed.

"The electorate cannot know how to judge people, unless they have access to critical information about what they are doing, why they are doing it, and how they are doing it," she explained.

Others argue that too much government secrecy can actually hurt national security.  Thomas Blanton, the director of the National Security Archive at George Washington University, says that was the conclusion of the bipartisan commission that investigated the 2001 terrorist attacks. He recently appeared on the U.S. public affairs channel, C-SPAN.

"It is not being safe to withhold information. That is the great lesson of September 11th," he noted.  "The 9/11 Commission found that it was precisely because of all this government secrecy that we cannot connect the dots."

It was that inability to "connect the dots," or link pieces of information that might have prevented the attacks, that many say led to the terrorists' success on September 11th.

Keeping information from the public is also expensive. The U.S. government currently spends nearly $8 billion each year to classify documents. 

A government report illustrates the trend toward classifying information.  From 1999 until 2004, the number of documents classified doubled to nearly 16 million.  During the same period, the release of declassified documents dropped by 100 million pages, to just 28 million.

Dennis Kucinich, a Democratic Party congressman from the state of Ohio, finds the trend troubling.

"By any measure, the administration has been classifying documents at a dizzying pace," he said.  "Under this administration, more agencies have been given authority to classify documents."

Historian Matthew Aid is one of the researchers who discovered recently that previously declassified documents were missing from the National Archives.  He says the administration decision to re-classify those documents is symptomatic of a larger, growing problem.

"What worries me about the reclassification program, is it is just a small part of many other things that we have lost since September 11th, which will make it very difficult to get these things back," said Mr. Aid.

Aid says the government is essentially, in his words, "stealing our history," when documents are locked up in a vault. And, he worries about what else the government may be doing in the name of national security.