Once again, the Iranians have prevailed in a hostage crisis. The smirking leader of Iran, Mahmoud Ahmadinejad, fresh from his latest demonstration of “performance-art politics,” is no doubt preparing his next stunt for the world stage.

And once again, the rogue regime in Tehran has been enabled by many Westerners, who knee-jerkingly sentimentalize hostages, reflexively look for the worst in their own country and instinctively adapt the language of their avowed enemies.

Any hostage who appears on television, or on Internet video, becomes an object of media fascination. By now, there’s an established ritual of recognition: First, reporters with cameras interview the hostage’s family. Second, they look for yellow ribbons in the hostage’s hometown. Third, they badger politicians, demanding to know why more hasn’t been done to free the hostage. Meanwhile, should the hostage be in a position to speak, well, the whole world – the whole media world, at least – hangs on every word.

In the case of the 15 British sailors and marines captured March 23, the Iranians got more help than they reasonably could have expected. The captives all seemed young and handsome – except for one, who was young and pretty. More to the point, they seemed all too eager to “confess” to being in Iranian waters.

“Whatever happened to name, rank and serial number?” – and nothing more – thundered The Daily Mail, a London newspaper. In Vietnam, some American POWs were tortured for years before they would help the enemy make its case – and some never gave an inch. But these Brits seemed to be having a happy enough time. And in being so free with their “confessions,” they undercut their government’s position.

Subsequent investigation might show more nuance to this story, but the British armed forces desperately need to review their training for those uniformed personnel who risk capture by the enemy – and figure out a way to punish those who flout specified procedures.

Speaking of procedures, one might ask: What’s wrong with the British Navy? How could the successors to Sir Francis Drake and Lord Nelson be so feckless as to allow the Iranians to grab one of their vessels without firing a shot? Surely some courts-martial, up and down the chain of command, are called for – although, of course, they won’t happen.

But let’s get back to the media, which have been played by the Iranians like a harp. When Ahmadinejad’s government announced the hostages were being “pardoned” as a “gift to the British people,” the media mostly went along with the Iranian spin.

CNN’s Tony Harris, for example, announced that Iran was “granting amnesty” to the Brits. In print stories, the words “pardon” and “amnesty” were mostly used inside quotation marks, as a way of saying that those words were the Iranian words, but on television and radio, when the words were spoken, that distinction was lost.

So the Iranian government can claim another success – at “semantic infiltration.” That’s the phrase used by late New York Sen. Daniel Patrick Moynihan to describe one side’s effectiveness at getting the other side to use its favored word choices – “the process whereby we come to adopt the language of our adversaries.” Thus, semantic infiltration is a kind of propaganda in which totalitarian regimes rename themselves as, say, “people’s republics.”

Moynihan further noted it’s predictable that evildoers would seek to conceal their true nature. But, he asked, “Must we aid them in that effort by repeating those words?” And finally, he warned that the good guys risk changing their own perceptions – losing their own moral bearings – if they make use of such semantically infiltrated words.

So we await the next Iranian “show.” Most likely, it will be brazen performance art, flouting international law and risking lives. And if the past is any guide, Western “critics” will eat it up.