With many convinced that President Mahmoud Ahmadinejad's hotly disputed landslide victory was an electoral coup, attention is focusing on the role played by Iran's enigmatic supreme leader, Ayatollah Ali Khamenei.
Did he willingly authorise the president's allegedly fraudulent election or was he pressed into making his glowing endorsement of Mr Ahmadinejad's tainted triumph? It is impossible to know, given the secrecy that envelops deliberations within the highest echelons of Iran's power structure. Yet it is clear that the campaign's contested outcome is generating a power struggle within Iran's divided leadership that could have more far-reaching repercussions than any turmoil on the streets. The state appears confident that it can contain any popular unrest by furious supporters of Mr Ahmadinejad's nominally defeated reformist rival, Mir Hossein Mousavi.
However, if the election was fraudulent, "it stores up trouble for the regime, leaving it temporarily stronger but weaker long-term as it has lost another opportunity to evolve peacefully", said a western former diplomat who served in Tehran. The most obvious theory is that Ayatollah Khamenei knows allegations of a rigged election are highly damaging to the Islamic system, but feared victory by a moderate candidate even more. Therefore, firmly in control, the supreme leader backed the alleged electoral coup. After all, he had consistently given his tacit support to Mr Ahmadinejad, a loyal if turbulent lieutenant, throughout the president's campaign. Both men share a deep suspicion of the West and a hardline stance on the nuclear dispute.
"In retrospect, it looks like the entire campaign was a show, in the sense that Ayatollah Khamenei was never going to let Ahmadinejad lose," Karim Sadjadpour, an Iran expert at the Carnegie Endowment for International Peace, wrote in a web briefing. But there are also intriguing suggestions the supreme leader's hand was forced. Fuelling such suspicions is that his message hailing the "divine blessing" of Mr Ahmadinejad's re-election was read to the media and not delivered in his own voice.
Ayatollah Khamenei has always been acutely aware that he never enjoyed the political and religious authority of Ayatollah Khomeini, his towering predecessor who led the 1979 Islamic Revolution. For that reason, Ayatollah Khamenei has craved legitimacy for himself and the system, viewing elections as the key to popular endorsement - even if his own position is not an elected one. Therefore, some analysts argue, he would not have allowed the legitimacy of the Islamic system to be undermined by an apparently sham election unless he was forced. They add that Ayatollah Khamenei does not enjoy the position of strength normally attributed to him - and that his power has been curtailed by the machinations of his supposedly subordinate president.
According to this theory, Mr Ahmadinejad, together with former and current members of the Revolutionary Guards and security forces - on whom he has lavished positions of political and economic influence - have seized real power, with the supreme leader reduced to a ceremonial figurehead. Writing in MideastAnalysis.com, Gordon Robison outlined several possible scenarios, one being that "Ahmadinejad and the security services have taken over. The supreme leader has been preserved as a figurehead, but the structures of clerical rule have effectively been gutted and are being replaced by a National Security State."
Mr Ahmadinejad and his colleagues, young revolutionaries in 1979 and now middle-aged, have developed careers in the Revolutionary Guards and other security services. "They may be committed to the Islamic Republic as a concept, but they are not part of its clerical aristocracy and are now moving to push the clerics into an essentially ceremonial role," Mr Robison wrote. Mr Ahmadinejad demonstrated his confidence in challenging powerful sections of the clerical and political old guard during his election campaign with vitriolic accusations of corruption campaign against Akbar Hashemi Rafsanjani, a former president. But Mr Ahmadinejad also dared to lash out against key aides of Ayatollah Khamenei.
The president's election was "in effect a coup using electoral machinery against not just the reformists but also the conservative and centrist factions and powerful individuals, clerical and non-clerical, who opposed Ahmadinejad", said the western former diplomat. Will Mr Ahmadinejad's still powerful if wrong-footed opponents take up Mr Ahmadinejad's gauntlet? They cannot rely on Ayatollah Khamenei, who ignored plaintive pleas from Mr Mousavi to intervene after the disputed official election results were released.
"Their only option [now] seems to be to directly challenge - or threaten to challenge - the supreme leader," said Trita Parsi, president of the National Iranian American Council. "Here's where the powerful chairman of the Assembly of Experts - Mousavi supporter Akbar Hashemi Rafsanjani - comes in." The Assembly is an elected body of 86 Islamic scholars charged with electing and supervising the supreme leader, whom it can also dismiss. The assembly has never sacked a sitting supreme leader, nor has it been known to challenge one.
"Only this assembly has the formal authority to call for Khamenei's dismissal, and it is now widely assumed that Rafsanjani is quietly assessing whether he has the votes to do so or not," Mr Parsi said. But many doubt Mr Rafsanjani has the muscle to risk such a course - and insist that Ayatollah Khamenei's authority should not be underestimated. "Rafsanjani doesn't have the battalions at the moment," said one Iran expert, who requested anonymity. "And what would the military do? After all, Khamenei has appointed all these people [military leaders] and can dismiss them. He has a very large organisation of his own - he is not a constitutional monarch who can be isolated."Meanwhile, Gary Sick, an Iran expert at New York's Columbia University, has catalogued the suspicious sequence of events that started on Friday afternoon. Together, they give the impression of a "well-orchestrated strike [by the ruling elite] intended to take its opponents by surprise - the classic definition of a coup", he wrote on his blog (http://garysick.tumblr.com).
"Curiously, this was not a coup of an outside group against the ruling elite; it was a coup of the ruling elite against its own people." Mr Sick added: "The willingness of the regime simply to ignore reality and fabricate election results without the slightest effort to conceal the fraud represents a historic shift in Iran's Islamic Revolution ? At the same time they have provided an invaluable gift to their enemies abroad."