I have been in Iran five hours a day every day in the past week. Although I'm in Canada, I've been virtually in Iran. I watched a live feed of street protests through a friend's webcam until it went dead after 48 hours because of the Government's internet crackdown.

During the past few days, I have become a communication hub. The government ban on texting via mobile phones, the jamming of the BBC Persian TV's satellite feed, the expulsion of overseas journalists and filtering of many foreign and Iranian news websites have forced me to send to my friends anti-filtering website links. I'm now the conduit of the latest information from and to foreign media outlets about the events inside Iran.

What is clear is that the protests are showing no signs of dying out - and that they have spread beyond Tehran and the middle classes to working-class neighbourhoods that were thought to be unequivocally pro-Ahmadinejad. My elderly grandparents' nurse told me of clashes in her working-class town of Pakdasht, a suburb of Karaj. The dispute over the presidential election has pitted neighbours against each other.

So how should we understand what is happening? First, Mir Hossein Mousavi and his supporters are not seeking regime change, but reform of the Islamic Republic. Second, the protests are also not just about the future of Iran, but a battle over the legacy of the 1979 revolution. And third, is that the protesters are not just drawn from a metropolitan elite.

Mr Mousavi was an Ayatollah Khomeini-inspired young revolutionary in the early 1980s. He was a member of the leadership council of the Islamic Republic Party and was one of the architects of the ousting in 1981 of Abolhassan Bani-Sadr, the Iranian President, who had fallen out with Ayatollah Khomeini, the Supreme Leader. He was then Prime Minister from 1981 to 1989 and after that served on the powerful Expediency Council until two months ago, when he made public his desire to run for president.

So Mr Mousavi is an insider - and he stood to save his revolution and legacy from the “pompous”, “illusory” President Ahmadinejad. Part of that legacy was the record of his premiership: it is remembered by ordinary Iranians as a Government for the poor that did much to alleviate poverty. Mr Ahmadinejad, of course, who poses as an anti-establishment populist, makes much of being a champion of the poor. But galloping inflation and squandered oil revenues have hit Mr Ahmadinejad's working-class base hard, allowing many of his voters to switch to Mr Mousavi.

But Mr Mousavi also appealed to the middle classes seeking a reformer. Young university students who were toddlers during his premiership prefer to remember Mr Mousavi as a friend of Mohammad Khatami, a former moderate president. Mr Khatami served under Mr Mousavi as an enlightened Minister of Culture. While many, including myself, were doubtful at first about Mr Mousavi's true aspirations, his defiance in the face of the rigged results and his role in the protests have established him as being true to his reformist colours - at least until he becomes president.

So what will happen next? Both sides have learnt the lessons of the fall of the Shah. In 1978 elements of the Shah's army lost their composure and fired on demonstrating crowds, causing a chain reaction of violence that led to the end of the Pahlavi dynasty. Yesterday I was told by a friend that the security forces withdrew when up to 100,000 protesters gathered in central Tehran: the Government is not ready to turn the Revolutionary Guards on the people. The demonstrators too are showing restraint: Iran is not like Gaza or the West Bank where people feel they have nothing to lose and are willing to accept martyrdom.

Ayatollah Khamenei, the Supreme Leader, is now caught in a trap. He has never escaped from the towering historical shadow of Khomeini, so he cannot appear biased against Mr Mousavi. This explains why a week after expressly endorsing the flawed election results, he had to tone down his rhetoric in a meeting with the representatives of the candidates and call for reconciliation. So Ayatollah Khamenei is buying time. He will want to exhaust every avenue - such as a recount overseen by the Guardian Council - so that the opposition is worn out. He wants to see President Ahmadinejad re-elected, perhaps with a smaller majority.

He has three other options if the protests continue. The first - impeachment - is the least likely. A saving grace for the Supreme Leader may come from the parliamentary investigation into the murderous assault on student halls in Tehran and Isfahan by the security forces. If the Interior Ministry is implicated, and the post-election popular unrest continues, the parliament may impeach Mr Ahmadinejad and ask Ayatollah Khamenei to sign his dismissal papers. This is still very unlikely.

The second is the Tiananmen option. He could shed much blood and order a mass purge of the reformist leaders who were once his revolutionary colleagues in the overthrow of the Shah.

The third is the poisoned chalice option. Ayatollah Khamenei faces a venomous dilemma similar to what Khomeini faced in 1988 - how to end the bloody Iran-Iraq War without losing face. Khomeini publicly stated that declaring peace would be tantamount to drinking from a chalice of poison. But nonetheless, he did it. It would be humbling for him, but the Supreme Leader could call a new election.

Mr Mousavi and the reformist leaders also face a dilemma - I call it Mossadegh's dilemma. They want change but they don't want to force change that would threaten the very existence of the Islamic Republic.

In 1953, after the first failed attempt by the West to overthrow Mohammad Mossadegh, Iran's Prime Minister, the Shah left the country. In his absence many asked Mossadegh to declare himself president. He refused. He truly believed that Iran should stay a constitutional monarchy and that the Shah should remain. He did not believe in “regime change”. Mr Mousavi and the reformist leaders, as well as the protesters, are grappling with the same Mossadegh dilemma as they too seek to reform the Islamic Republic short of regime change.

Even if the protests fade, Mr Mousavi may have created a civil disobedience movement. Iranians will go to the polls for municipal elections next year - and in early 2012 there will be parliamentary elections. This week's events could be the shape of things to come as Iran lurches from one electoral crisis to another.

Shahram Kholdi is a graduate of Azad Islamic University in Tehran, and is a writer and academic based in Canada

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