In the open Daniel Patrick Moynihan walks through a Columbus Day Parade crowd in Manhattan, 1994. (James Leynse via Corbis Images)

The ease with which the United States government creates new state secrets masks the ultimate cost of the secret’s production. Once minted, a secret must be guarded lest a spy sneak in and pluck it from the bunch—or a Chelsea Manning, an Edward Snowden, or a lesser leaker with a security clearance release it into the wild. Vaults must be built, moats dug, and guards hired, trained, and paid. Add to that the cost of routine audits, to make sure nobody has picked the locks, and the expense of the annual security clearances for the spooks, bureaucrats, and IT specialists who make, sort, use, and maintain the secrets. At last count, nearly five million people in the US were cleared to access Confidential, Secret, or Top Secret information, a number that includes both government employees (like Manning) and contractors (like Snowden).

Official secrets have been reproducing faster than a basket of mongooses thanks to the miracle of “derivative classification,” and this rapid propagation has compounded the maintenance costs. Whenever information stamped as classified is folded into a new document—either verbatim or in paraphrased form—that new derivative document is born classified. Derivative classification—and the fact that nobody ever got fired for overusing the classified stamp—means that 92.1 million “classification decisions” were made in FY 2011, according to a government report, a 20 percent increase over FY 2010. Once created, your typical secret is a stubborn thing. The secret-makers’ reluctance to declassify their trove is legendary: In 1997, 204 million pages were declassified, but since 9/11 only an average of 33.5 million pages have been declassified annually.

The secrets glut imparts another cost, one that can’t be measured in dollars, as Daniel Patrick Moynihan warned in his 1998 book, Secrecy: The American Experience. Just as excessive economic regulation blocks efficient transmission of the market’s supply and demand signals, the hoarding of secrets locks vital knowledge away from politicians, policymakers, and the public, who need the best information to conduct informed debates and make wise decisions. However difficult the quandary when Moynihan was writing, it’s much worse now. By FY 2011, the volume of new classified documents created annually had risen to 92 million from six million at the time Secrecy was published.

While Moynihan nurtures a civil-libertarian sentiment, his primary thrust is utilitarian: The stockpiling of too many secrets renders the nation less secure, not more, because it forces us to make decisions based on poor-quality information. In our attempts to blind our adversaries, he points out repeatedly, we end up blinding ourselves. The information blackout also hinders the public’s ability to hold the secret-keepers accountable for what they do. Kept too close to the vault, important secrets don’t get properly vetted, which results in policy being sent off course by “incorrect” secrets. (“The mistakes, you see, were secret, so they were not open to correction,” as historian Richard Gid Powers puts it in Secrecy’s introduction.) Secrets prevent sympathetic legislators—here Moynihan was writing about his relationship with President Ronald Reagan—from defending a colleague’s foreign-policy positions without knowing what they are. And finally, the routinization of the classified process, this willy-nilly banging of “Secret” on the most banal documents, creates a surplus of secrets that increases the difficulty of protecting the vital ones.

Moynihan died in 2003, a few years after completing three terms as a Democratic senator from New York. If he were still serving on the Select Committee on Intelligence, one can’t imagine the certified anti-communist and self-identified hawk applauding Manning and Snowden for loosing the secrets they vowed to protect. But one can easily imagine Moynihan leading a seminar on secrecy mania, waving thumbdrives and CDs to symbolize the gigabytes of classified information the two leakers so easily pilfered and distributed, and decrying the government’s secrecy fetish.

Jack Shafer writes a column about the press and politics for Reuters.