IN the past few days, those who think President Bush can do nothing right have exhausted the thesaurus in search of adjectives to label his decision to send an emissary for multinational talks with Iran.

This, we're told, is a U-turn and a sign of caving in - the first time since the mullahs seized power in 1979 that Iran and the United States are engaging in a diplomatic encounter. The reality is more complex.

To start with, this is far from the first time that the two sides have met. President Jimmy Carter sent envoys before and during the hostage crisis. President Ronald Reagan sent his own representative - remember the "Iran-Contra" scandal?

US and Iranian diplomats met at least a dozen times during the Clinton and first Bush presidencies, and under George W. Bush, the two sides have talked on several occasions since 2002 over Afghanistan and Iraq.

So what is new? This month, Washington signaled its readiness to attend the so-called 5+1 talks in Geneva - and Tehran gave its consent. Yet these talks don't touch on bilateral US-Iran relations. Assistant Secretary of State William Burns will sit beside envoys from China, Russia, Britain, France and Germany to hear Iran's Saeed Jalili respond to the latest "package" offered by the European Union. The EU's foreign-policy czar, Javier Solana, will lead the dialogue on behalf of the 5+1 group.

Tehran describes Washington's decision to attend the talks as a victory for the revolution. President Mahmoud Ahmadinejad has gone further and called on his followers to "prepare for a new post-American world." Again, reality is more complex.

To start with, "Supreme Guide" Ali Khamenei had to set aside a law passed by the Islamic Majlis (parliament) banning diplomatic contact with the American "Great Satan." The Geneva encounter may be painful for Washington neocons - but it's even more so for Tehran radicals.

The talks are about one thing only: Tehran's response to the EU offer, which hinges on the central demand that Iran comply with several UN Security Council resolutions. The resolutions' bottom line: Iran should verifiably disband its uranium-enrichment program, thus jettisoning all possibility of developing an atomic bomb.

Tehran says it will never do that, even if that means war. The 5+1 group insists it won't accept anything less - that Tehran's refusal could lead to other resolutions that, in time, could lead to military action under Chapter 7 of the UN Charter.

The talks will show if either side is prepared to blink. Three outcomes are possible: 1) Iran will comply in exchange for face-saving measures. 2) It won't budge. 3) The two sides will agree on a diplomatic fudge - something of which Burns is a master.

The first two possibiliites would each be good news: Tehran abandons its bomb, or the situation at least becomes more clear, proving wrong those who claim that the crisis is solely due to Bush's refusal to authorize dialogue with Iran.

But Burns may produce the third outcome. After all, He is the architect of the fudge over Libya - which let Moammar Khadafy off the hook in exchange for abandoning a nuclear project that turned out to be no more than pie in the sky.

And he helped shape the deal with North Korea. By pulling down a cooling tower in front of TV cameras, plus a few other symbolic gestures, Pyongyang has managed to buy time to get out of its economic and political impasse.

Whatever these talks produce, one fact won't change: The Khomeinist regime is unlike any of its neighbors, nor indeed any other system in the world. Its ambition is to reshape the Middle East, and later the rest of the world, after its own fashion. And, since the United States also wishes to create a new balance of power in the Middle East, the two rival ambitions are bound to clash at some point.

Everyone has been talking to the mullahs for 30 years in the hope of changing their behavior. But the problem isn't the regime's behavior, but its nature. A regime that is at war against its own people on a daily basis can't make peace with others.

Talk is no substitute for policy. In 1990, US Secretary of State James Baker held high-profile talks with his Iraqi counterpart, Tariq Aziz. The talks proved that neither side could retreat from its basic position. The rest, as always, is history.

Amir Taheri's next book, "The Persian Night: Iran Under the Khomeinist Revolution," is due out this fall.