Throughout much of Ramadan, the Tehran media – controlled by "Supreme Guide" Ali Khamenei – conducted a campaign of vilification against former President Muhammad Khatami.

This is not the first time that Khamenei unleashed his anger against Khatami. The former president was already accused of being in cahoots with Freemasons and "Zionist" conspirators trying to bring down the Khomeinist regime.

This time, however, things are different for at least three reasons.

The first reason is that the attacks are no longer about political differences but focus on Khatami's person.

He is portrayed as a "coward" and a man of boundless ambition who would do anything to regain a share of power.

Secondly, this time almost all opponents of the regime have echoed the attacks, creating the impression that Khatami is rejected by all sections of Iranian opinion.

Finally, and contrary to claims by the Tehran media, this time Khatami is presenting an analysis that merits attention.

He is developing two themes.

The first is that the regime is still capable of reform through the application of its Constitution.

Thus, he proposes to create a loyal opposition, seeking not regime change but change within the regime.

The second theme Khatami is developing is that the reason Iran finds itself in crisis is President Mahmoud Ahmadinejad's poor leadership.

Based on that analysis, Khatami wants "reformist" elements within the regime to unite around a presidential candidate next June.

Former President Hashemi Rafasnjani, barred from standing because of legal age limits, has endorsed Khatami's analysis. Khatami's views have also found a favourable echo with former Interior Minister Abdullah Nuri, who is not too old to stand for president.

If the three pool their resources and mobilise their support base they would be able to create a significant loyal opposition.

There is no need to waste time on Khamenei's attack squad. By opting for Stalinist style personal attacks they have scripted themselves out of serious debate.

However, the views of those within the opposition who have joined the chorus of attacks on Khatami deserve comment. Mir-Hussein Mussavi and Mahdi Karrubi, unsuccessful candidates in the last presidential election, have signalled their opposition to participation in next June's election. Because both are under arrest the views attributed to them might not exactly reflect their sentiments. However, it is clear that they have doubts about Khatami's analysis.

The bulk of what Khatami envisages as the future loyal opposition to the regime appears to be hostile to his views. Here we have a hotchpotch of groups that participated in the uprisings of 1978-79 that swept the mullahs to power. These include a dozen leftist parties, the remnants of the Mussadeq movement, outfits representing ethnic minorities, and middle class elements that dreamt of revolution as a path to greater freedom.

Over the past five years hundreds of former Khomeinist officials have fled to Europe and the United States. Thus, we now have elements from the clergy, the Revolutionary Guard and Khomeinist technocracy roaming Western capitals talking of reform at home and friendship with the United States.

But, could those who have occupied positions in this regime claim that only the elections they win are good and valid?

My guess is that a good chunk of Ahmadinejad's support base is getting ready to join this nebulous of revolutionary disappointment.

The bulk of the real opposition to the regime, those who try to overthrow it, have dismissed Khatami's latest position as irrelevant. Some have echoed personal attacks on Khatami by describing him as "opportunist" or "hypocrite".

I don't think that Khatami is a hypocrite and, as for him being an opportunist, that would be no surprise for a professional politician.

Khatami is posing several fundamental questions.

The first is whether one could hold credible elections within the Khomeinist system?

I don't doubt Khatami's sincerity but I fear he is trapped by wishful thinking. The regime has never held credible elections if only because it pre-selects the candidates. Khomeinist elections may have had some significance because they indicated the balance of forces within the regime. After the latest elections that interest has vanished. Now we know that Khamenei decides who wins.

The next question is whether a loyal opposition could function in any meaningful manner? The problem has two sides. Khatami and others in the putative loyal opposition must accept the results of elections organised by the regime, even if they lose. They don't. On the other side, those who win the elections allow no space for the losers.

The next question is whether one could reform the regime by changing part of its personnel?

My answer is no, although I admit that, on occasions, change of personnel could produce trompe l'oeil effect. In the old Soviet Union, Nikita Khrushchev was not as bloodthirsty as Stalin and not as stupid as Malenkov.

The third question is whether Iran needs change within the regime or regime change?

Khatami's answer is yes. Mine is no.

Of course, if change within the regime were possible, Iran would emerge from its historic crisis faster and at a lower cost.

But it is not. The absurd concept of "Wilayat al-Faqih" (Rule by a Mullah) is the negation of freedom of choice implied in any credible electoral exercise.

The Khomeinist system is built on faulty foundations. A Persian proverb puts it neatly: when the first brick is laid obliquely the wall rises obliquely to the stars!

The only way out of the historic impasse created by Khomeini is regime change.

Khamenei has destroyed the little potential for change that the regime might have once had. Today, he, too, is a prisoner of a system geared to self-perpetuation through absurdity. Five years ago Ahmadinejad put it neatly: Our train has no stop and no rear-gear! We just surge ahead!

Regime change or change within the regime?

The great debate must take place. The next few months will show which of the two rival analyses are closer to reality.

Amir Taheri was born in Ahvaz, southwest Iran, and educated in Tehran, London and Paris. He was Executive Editor-in-Chief of the daily Kayhan in Iran (1972-79). In 1980-84, he was Middle East Editor for the Sunday Times. In 1984-92, he served as member of the Executive Board of the International Press Institute (IPI). Between 1980 and 2004, he was a contributor to the International Herald Tribune. He has written for the Wall Street Journal, the New York Post, the New York Times, the London Times, the French magazine Politique Internationale, and the German weekly Focus. Between 1989 and 2005, he was editorial writer for the German daily Die Welt. Taheri has published 11 books, some of which have been translated into 20 languages. He has been a columnist for Asharq Alawsat since 1987. Taheri's latest book "The Persian Night" is published by Encounter Books in London and New York.