The U.S. government, faced with the publication on the Internet of a quarter-million cables sent by U.S. embassies in recent years, has responded just as it did when WikiLeaks posted similar troves of secret messages about the wars in Afghanistan and Iraq on the web earlier this year. It has solemnly warned that WikiLeaks is endangering the lives of American diplomats, soldiers, and spooks.

"Such disclosures put at risk our diplomats, intelligence professionals, and people around the world who come to the U.S. for assistance in promoting democracy and open government,” the White House declared. “By releasing stolen and classified documents, WikiLeaks has put at risk not only the cause of human rights but also the lives and work of these individuals."

Hmm. Might there be some exaggeration here? Does the U.S. ambassador to Moscow really face assassination for reporting, in late 2008, that President Dmitri Medvedev “plays Robin to (Prime Minister Vladimir) Putin’s Batman”?

Will United Nations Secretary-General Ban Ki-moon really order a hit on U.S. Secretary of State Hillary Clinton now that he knows she ordered U.S. diplomats to collect the details of confidential networks used for official communication by senior UN officials, including passwords and personal encryption keys. (She also wanted their frequent flyer numbers, credit card details, fingerprints, iris scans, and DNA biometrics.)

Will French President Nicholas Sarkozy have the U.S. ambassador murdered for saying that he has a "thin-skinned and authoritarian personal style"? Will Italian prime minister Silvio Berlusconi put out a kill order on Elizabeth Dibble, U.S. charge d'affaires in Rome, for saying that he is "feckless, vain, and ineffective"?

And by the way, the leaked documents don’t only deal with “people around the world who come to the U.S. for assistance in promoting democracy and open government,” as the White House pompously put it. They also reveal who came to the U.S. for assistance in suppressing democracy and open government—and quite frequently got it.

The official outrage is as synthetic as it is predictable, and what drives it is not fear for the lives of American diplomats and spies but concern for their careers. But how did a big, grownup government like that of the United States blunder into the error of making all this “secret” material so easily available?

It made the elementary mistake of thinking that electronic communications could really be kept secret, even when widely disseminated, if you just surround them with a sufficiently impressive clutter of passwords, security clearances, and encryption. Any historian could have told them they were wrong. If it’s written down, then it will come out sooner or later. In this case, it was sooner.

Before I realized that journalists have more fun and make (a little) more money, I trained as an historian and did research in the archives of various foreign ministries. I always pitied my colleagues working in earlier periods of history, when most things were decided face to face. By contrast, in the late 19th and early 20th centuries, the period that I was studying, governments had got so big that everything was written down.

Documents would pass from one desk to another, and each recipient would note his comments in the margin and initial them. They had to do it that way, writing down what they really thought, because there were no telephones. It was a system that allowed subsequent historians to trace the way decisions actually got made—about 30 to 50 years later, when the files were finally opened to researchers.

Then, in the decade or so before the First World War, all those officials got telephones, and that system died. The officials had their confidential discussions on the phone, real motives never got written down, and the documents usually contained only a sanitized version of the policy debate. It got a lot harder to do good history.

What the U.S. Defence Department thought it had invented in the Siprnet (Secret Internet Protocol Router Network) was a way to distribute confidential information widely, like in the good old days, but without jeopardizing secrecy. Except that it wasn’t secure, as the massive dump of cables on WikiLeaks demonstrates.

All you needed to access the Siprnet was a “Secret” security clearance. When the number of people with a “Secret” clearance or above was last counted by the General Accounting Office in 1993, there were more than three million of them. There are probably twice as many today. And all it takes is one of them to send the data to WikiLeaks, and the whole system is compromised.

The U.S. government will persist in trying to get Julian Assange, the founder of WikiLeaks, jailed on one charge or another, but he is just the tip of the iceberg. The more widely you distribute information, the more likely it is to leak. If you disseminate it very widely by electronic means, it’s almost certain to leak.

So distribution lists will get a lot shorter in the U.S. and elsewhere. This may result in some minor degradation of the decision-making process, but not much, really. The most striking thing about those quarter-million messages is that they contain almost no real surprises. You’d be just as well informed about the world if you read a couple of good newspapers every day.