Friday will be one of the most important days in Iran's recent history - the moment at which it will have to decide which direction to take.
At first sight the available choice in the run-off for the presidential election looks distinctly unappetising - the off-the-wall fundamentalist mayor of Tehran, whose chances were rated so low that no one bothered to find a place for him to give a victorious press conference, versus an elderly conservative who achieved relatively little during his eight previous years as president.
Yet these two men, Mahmoud Ahmadinejad the mayor, and ex-President Akbar Hashemi Rafsanjani, represent very different ways forward for Iran, at a difficult and important time for the region.
Mr Rafsanjani has underlined his interest in women's issues
Mr Ahmadinejad stands for a return to the values of Ayatollah Khomeini's revolution, the period after 1979 when Iran challenged the Americans and the West in general to do its worst.
He believes that Iran has an inalienable right to produce nuclear weapons if it chooses.
As mayor of Tehran, he closed down Western-style fast food restaurants wherever he could, and obliged the city's male employees to grow beards and wear long-sleeved shirts.
By contrast, Mr Rafsanjani is a man who believes that politics is the art of the possible.
It is largely because of him that life in Iran gradually began to move away from the fierce restrictions of the early revolution.
It was he who managed to persuade Ayatollah Khomeini to end the ruinous war with Saddam Hussein's Iraq.
Neither the conservatives nor the reformers in Iran like Mr Rafsanjani. He has gone much too far for the conservatives, and not far enough for the reformers.
Unlike any of them, he understands the art of the deal, and is more concerned with what he can get away with than with making big statements.
It matters a great deal which of these two men wins, because - thanks to the US-led overthrow of Saddam Hussein - Iran is now by far the strongest power in the region.
As a result of the invasion of 2003, which freed Iraq's Shia majority from Saddam's ferocious control, and the election this year which gave the Shia the dominant role in Iraqi politics, Iran and Iraq are now close.
There were even suggestions - strongly denied - that Iraqi exiles acting as agents for Iran encouraged the Bush administration to invade Iraq.
It is a serious mistake to underestimate Iran's strength and political sophistication.
To listen to President Bush or Condoleezza Rice you might think that it was just another Afghanistan, backward and instinctively fundamentalist. Not so - Iran is one of the most advanced societies in the region.
The only reason the fundamentalist Mahmoud Ahmadinejad got through to the second round of the presidential election is that many reformists stayed away from the poll in protest at the highly limited range of candidates who were allowed to stand.
Two of the main reformist candidates now claim the result was a fix. But maybe the reformists simply cancelled each other out, and let their most extreme opponent through.
The reality of Iranian politics is that the great majority of Iranians badly want change. That was made absolutely clear in the elections of 1997 and 2001. Both times Mohammed Khatami received more than 80% of the vote, precisely because he was a reformist.
But during his eight years as president he achieved little apart from liberalising the press, which has become one of the most vibrant in the entire region.
His efforts to open up to the West and lift the annoying intrusion of the state into the way people live their everyday lives failed.
Real power in Iran does not rest with the clear democratic choice of the people. It is held by the unelected Supreme Leader, Ayatollah Khamenei, and a variety of other religious authorities, who can intervene as they see fit.
Iranians are hoping for greater reforms to be introduced
This is the system which Mr Ahmadinejad, the mayor of Tehran, represents. He is a strong supporter of Ayatollah Khamenei.
If he wins on Friday, most of the small gains which the reformists have made will be wiped out. It will not just be city employees who will have to grow beards.
That is why, with plenty of reluctance, most people will turn out to vote for Mr Rafsanjani.
In his election campaign he has been promoting himself as a friend of reform, and emphasised his interest in women's issues. He clearly understands the importance of changing Iran.
He also understands that although most Iranians relish their independence from the West - during the 20th Century both Britain and America treated Iran as if it were a kind of colony - they do not want to be so cut off from the outside world.
And Mr Rafsanjani knows how to cope with difficult and dangerous political situations.
We can expect him to finesse the nuclear question with some skill.
But he will not be a pushover for the Americans. Iran is strong and remarkably powerful nowadays, and Mr Rafsanjani knows that after Iraq, President Bush no longer has the strength nor the will to launch another invasion in the region.
His main struggle, though, will be against the conservative establishment in his own country. If he cannot beat them, he will be just another failure. And he certainly understands that.
A very inspiring article, Mr Simpson. There is much confusion and anger around the election results among liberal Iranians. Many are disillusioned with their compatriots and the establishment, and apathy could yet yield another victory for hard-liners. I hope the divided reformist camp can get its act together and prevent the ascent of a militarist government. Maybe then, they can rise together and consolidate their support for a comeback at the next city council elections some 2 years from now.
Siroos Kiani, Vancouver, Canada
Mr Simpson's analysis is, as usual, spot on. Very few "westerners" know about the depth and sophistication of Iranian society. As a Pakistani well-wisher of Iran and Iranians, I hope the Iranian people take a step closer to achieving their goals by making the right decision in an election that is far from perfect, but an election nevertheless.
Nausherwan Lahori, Lahore, Pakistan
I have read few articles as good as Mr Simpson's. I live in the USA and while in many cities around the US, Iranians could vote over here we didn't have a station. This Friday I hope to drive 4 hours to the nearest available polling station to vote against Ahmadinejad. While I respect him for being straight forward with his views, I vigorously disagree with his vision. Mr Rafsanjani may not be the ideal candidate in a not so ideal system, but for now democratic aspirations rest with him.
Sultan Mehrabi, USA
Thanks for some context and depth to a political situation that is very important to understand. I hope that Mr Rafsanjani is elected and that our leaders put steady pressure on his government to improve human rights while providing respectful support to him as he nudges Iran to a more secular, moderate state.
Gary Ockenden, Nelson, Canada
We're caught between a rock and a hard place: to choose from the bad and the worse. Rafsanjani's just getting away with everything since in the current situation he's become the "less bad". But how can we convince ourselves to write down the name of someone we disapprove of just because the other is worse? It's a difficult decision: whether to vote or to abstain.
Homa Musavi, Tehran, Iran
Hardly surprisingly - a very good article by JS, picking up on crucial points. Due to its relative sophistication, strong sense of nationhood, the population's (particularly young sections of it) openness to external influences, access to the outside media etc, Iran could really become THE organic model state for a stable Middle East. What it would take is skillful, sensible yet effective support of the West for the reformist tendencies. GW Bush's decision to make it a part of axis of evil and unconditional support for Israel are exactly the opposite policy direction than the one that should be taken, and can only strengthen reactive elements in Iran.
I have a feeling that Rafsanjani and Bush will strike a deal. The US will get the Central Asian (and Iranian) oil through Iran to the Persian Gulf, and Iran will get closer ties to USA (which the young people there would like) and concessions on WTO/nuclear power. Win-win for everyone? No. Because at home, liberty will continue to be suppressed, and the world won't care as long as it gets cheap oil.
Ray, Coram, New York