We learned last week that a dubious program in which thousands of pages of once-classified historical documents were removed from public view was protected by an agreement in which the National Archives and Records Administration covertly helped the Air Force, the CIA and other agencies to pull the documents and cover up the reclassification effort.

The 2002 agreement says the aim of the program was to cull documents that had been wrongly declassified: "The release of those documents would harm the national security interests of the United States by revealing sensitive sources and methods of intelligence collection." That the keepers of the nation's archival history would secretly collude with military and spy agencies to lock away selected parts of that history is, by itself, cause for concern. But the program, which began in 1999 and was dramatically accelerated after 9/11, went far beyond reversing genuine mistakes in declassification.

The New York Times reported in February that the program apparently had morphed into a license for spies and diplomats to whitewash some of the agencies' most dubious and embarrassing acts. Historical CYA, in short. Cover Your Asininities.

How else to explain the sheer volume of the vacuuming - more than 55,000 pages within 10,000 documents, mostly from the 1940s and '50s? One of the documents identified by researchers as among the missing contains a CIA assessment of whether the Chinese would soon intervene in the Korean War. The CIA said probably not. Two weeks later, more than a quarter of a million Chinese soldiers flooded into Korea, overwhelming U.S. units near the border. Dozens more examples are of equal CYA quality.

The National Archive is reviewing how it handles reclassification requests in order to find a better balance between national security and the public's right to know. That should be easy, since none exists now.

We also suggest that the agency get out of the spy business and get back to protecting the integrity of our written history.