Some very interesting diplomacy is definitely afoot in Tehran and Paris. Ali Akbar Velayati (right), the right-hand man of Iran's Supreme Leader Ali Khamenei and a former foreign minister, published a letter in France's Libération newspaper Wednesday that leaves no doubt about who's ultimately in charge of the nucelar file. Here's a translation by FP's resident Frenchman, Randolph Manderstam:

A European recently asked me who was leading Iran. The answer is clear. When it comes to essential questions of strategy, the constitution, approved by universal suffrage, confers final decisions upon the supreme leader. It is according to this principle, under which the main decisions taken by Ayatollah Khamenei in the last 20 years were applied, that we can judge the past and forsee the path of our diplomacy.

Despite the vastness of his powers, the supreme leader… only intervenes in extremely important cases, leaving those responsible for the state to solve the other problems themselves. Under Imam Khomeini just as under Ayatollah Khamenei, Iranian diplomacy has worked on developing contacts with other countries.... By receiving the dignitaries and leaders of numerous states and by communicating with them, the leader has given undeniable examples of his crucial presence in Iranian diplomacy.

I spoke this morning with Carnegie's Karim Sadjadpour about the letter, and he told me it was a "very important" signal coming from Velayati.

The main message? Don't listen to the rantings of that Ahmadinejad fellow -- the supreme leader is called "supreme" for a reason. "Khamenei's not necessarily the micromanager, but he's the macromanager, so all important issues go by him," Sadjadpour said.

Why proclaim this in a French newspaper? The backstory here is fascinating. Last year, French President Nicolas Sarkozy reached out to Khamenei in the hopes of reaching a breakthrough in the stalled nuclear negotiations. Velayati was to be dispatched to Paris to lay the groundwork for a possible meeting between Sarkozy and Khamenei, and in November he went to brief Ahmadinjad as a courtesy before heading off on his mission. Not only did the Iranian president humiliate Velayati by scheduling him for a midnight meeting and then making him wait for several hours, but he then sent a letter to Sarkozy that was so rude and condescending, it killed any hope of a France-Iran summit. According to Le Monde, Ahmadinejad said Sarkozy was "young and inexperienced," and French diplomats said the letter contained "veiled threats."

More recently, a civil servant and Ahmadinejad ally named Abbas Palizdar publicly accused a number of top clerics of corruption. Several of them are close associates the supreme leader. Too close, in fact, and Palizdar was arrested for "propagating lies." Rumor has it Khamenei saw this incident as Ahmadinejad crossing the line. So, not only is Khamenei, through Velayati, trying to make clear that Ahmadinejad is not the guy to talk to, he's indicating his disgust with the Iranian president and putting him in his place. "I think Khamenei is frustrated with Ahmadinejad's antics. This may have been the last straw," said Sadjadpour.

As for a détente with France or a breakthrough on the nuclear program? Don't bet on it. Iran's recent diplomatic offensive is most likely a "delaying tactic" intended to "cool the temperature" in light of all the recent news, according to Sadjadpour. But it sure makes great political theater. Pass the popcorn.