I’m sure the Russian people will be shocked—shocked!—to discover that U.S. diplomats think the Russian president, Dmitry Medvedev, “plays Robin to Putin’s Batman.” Italians will be equally horrified to learn that their prime minister, Silvio Berlusconi, is considered “feckless, vain, and ineffective as a modern European leader,” just as the French will be stunned to hear President Nicolas Sarkozy called “thin-skinned and authoritarian.” As for the Afghans, they will be appalled to read that their president, Hamid Karzai, has been described as “an extremely weak man who did not listen to facts.”

And anyone perusing the semi-secret diplomatic cables published by WikiLeaks this week will find more of the same. Zimbabwe’s Robert Mugabe is a “crazy old man.” Muammar Qaddafi of Libya travels with a “voluptuous blonde” whom he describes as his “senior Ukrainian nurse.” In the coming days, there will be many things to say about the specific details of these newly public documents. But before we get into all that, let’s not lose the main point: Above all, this leak contains a treasure trove of things people regularly say off the record that they never say in public. These aren’t records of human-rights abuses, they are accounts of conversations. And—just like July’s WikiLeaks revelations about Afghanistan—this one confirms much that was publicly known, openly discussed, and even written about before.

The cables “reveal,” among other things, that the United States is (surprise!) lobbying others to organize sanctions against Iran, that South Korean diplomats have discussed what would happen if North Korea collapses, that U.S. diplomats have been bribing other countries to accept ex-prisoners from Guantanamo Bay. (I suppose it is “news” that the United States spies on the United Nations, but forgive me if I am not as horrified as I should be.) Germany’s Der Spiegel concludes, furiously, that the United States “seeks to safeguard its influence around the world.” I’d be a lot more worried if the opposite were true.

What is truly novel is not the information, much of which has been reported before, but the language. Normally poker-faced diplomats are quoted making unflattering and occasionally amusing assessments of their interlocutors. Not all of them are Americans: The Saudi king thinks the Pakistani president is “rotten”; France’s top diplomat thinks Iran is a “fascist state”; Britain’s national bank chairman thinks his prime minister is “shallow”; and so on.

This is certainly embarrassing for those who made the remarks. I am less sure whether their revelation gets us anywhere: On the contrary, it seems that in the name of “free speech” another blow has been struck against frank speech. Yet more ammunition has been given to those who favor greater circumspection, greater political correctness, and greater hypocrisy.

Don’t expect better government from these revelations, expect deeper secrets. Will the U.S. ambassador to Country X give Washington a frank assessment of the president of X if he knows it could appear in tomorrow’s newspaper? Not very likely. Will a foreign leader tell any U.S. diplomat what he really thinks about Iranian President Mahmoud Ahmadinejad if he knows it might show up on WikiLeaks? I doubt it. Diplomatic cables will presumably now go the way of snail mail: Oral communication will replace writing, as even off-the-record chats now have to take place outdoors, in the presence of heavy traffic, just in case anyone is listening.

In the modern world—at least the sloppy, open, hackable Western world—any other form of frank discussion will soon be impossible. The State Department isn’t the first to learn this: No American general will ever again give a journalist full access, as did the hapless Stanley McChrystal. Because he revealed that—like every other general in history—he sometimes disagrees with the politicians back home, and because his interlocutor chose to publish his grumbling, he had to resign.

The result: Very soon, only authoritarian leaders will be able to speak frankly with one another. A Russian official can keep a politically incorrect statement out of the newspapers. A Chinese general would never speak to a journalist anyway. Low-level officials in Iran don’t leak sensitive information to WikiLeaks because the regime would kill them and torture their families. By contrast, the soldier who apparently leaked these diplomatic cables will probably live to a ripe old age.

In fact, the world’s real secrets—the secrets of regimes where there is no free speech and tight control on all information—have yet to be revealed. This stuff is awkward and embarrassing, but it doesn’t fundamentally change very much. How about a leak of Chinese diplomatic documents? Or Russian military cables? How about some stuff we don’t actually know, like Iranian discussion of Iranian nuclear weapons, or North Korean plans for invasion of South Korea Korea? If WikiLeaks’ founder Julian Assange is serious about his pursuit of “Internet openness”—and if his goal isn’t, in fact, embarrassing the United States—that’s where he’ll look next. Somehow, I won’t be surprised if he doesn’t.

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