The Iranian revolution is discovering that, in its thirtieth year, it has grown old. The wave of street demonstrations following the presidential election of 12 June 2009 reveal its fruits: "two peoples" who announce themselves in huge sociological differences - of appearance, affiliation, body-language, political slogans. This goes far beyond even the conflict over the results of the election; it involves a clash over the nature of the regime and Iran's future direction.

Also on the disputed election in Iran and its bitter aftermath:

"Iran's election: people and power" (15-18 June 2009) - a symposium with Ramin Jahanbegloo, Anoush Ehteshami, Nazenin Ansari, Omid Memarian, Grace Nasri, Rasool Nafisi, Nasrin Alavi, Sanam Vakil, and Farhang Jahanpour

Farhang Jahanpour, "Iran's stolen election, and what comes next" (18 June 2009)

Hossein Bastani, "Iran's coming storm" (22 June 2009)

Many comparable experiences show how natural it is for state authorities to respond to such circumstances with formulaic stammering. Mahmoud Ahmadinejad'spronouncements during his post-election trip to Russia were in this classic tradition as well as true to form. At the very moment the regime he epitomises was putting its own possible demise on the agenda, Iran's president was happy to drone on about the "retreat of the American empire" and foreign "conspiracy". This was combined with the contradictory suggestions that Iran was witnessing  a "renewal of the revolution's youth" and that a limited investigation of some contested votes was possible. The stumbling confusion, evident too in the mixed messages of Ayatollah Khamenei's speech at Friday prayers in Tehran on 19 June, was difficult to hide.

The larger truth is that Iran is repeating a pattern that all revolutionary regimes at some point have to acknowledge: namely, they establish their new "legitimacy" via an early display of "illegitimacy", but this itself eventually creates fertile seeds for their own demise. Revolutions oppose and then acquire power; establish their surveillance mechanisms and repressive tools to preserve themselves, in the process winning a new swathe of adherents fired less by zeal than by material gain and the right to boss others; and purge and consume their own children.

Iran too lived through this in the post-1979 years, in the successive toppling of Mehdi Bazargan, Abou-Hassan Bani Sadr, Sadeq Qotbzadeh, Ibrahim Yazdi, and others. At the time, the revolution's rising arc and youthful energy were much stronger than any morbid indicators. The occupation of the United States embassy in Tehran ("the nest of spies"), and the zealous response to Saddam Hussein's invasion in 1980 were signs of a deeper momentum that  obliterated internal conflicts.

But by the late 1990s, when the revolution had survived a decade in power and the brutal war with Iraq (1980-88), the cracks began to show. A fierce wave of social discontent erupted, creating doubts in the regime's inner circles about the revolution's legitimacy and authority.

This movement was symbolised by Mohammad Khatami'svictory in the presidential votes of 1997 and 2001, though his reformist agenda was undermined internally by hardline opposition and externally by the dark climate created by George W Bush and his "war on terror" (which included invading of two of Iran's neighbours, and anathematising Tehran itself as part of an "axis of evil"). This doctrine  refuelled the revolutionary state's authority and legitimacy even when so many Iranians were disaffected from it and seeking another way. The moment of the early 2000s, handicapped by poor organisation and lack of leadership, failed to articulate a national, trans-sectarian interest and ran out of steam. The result was Mahmoud Ahmadinejad (see Fred Halliday, "Iran's revolutionary spasm", 30 June 2005).

Hazem Saghieh is senior commentator for the London-based paper al-Hayat

Hazem Saghieh's articles on openDemocracy include:

"Rafiq al-Hariri's murder: why do Lebanese blame Syria?" (21 February 2008)

"Lebanon's election, no solution" (20 June 2005)

"Syria and Lebanon: keeping it in the family" (14 December 2005)

"How the European left supports Lebanon" (14 August 2006)

"Lebanon's internal struggle: two logics in combat" (19 December 2006)

"The Arab defeat" (11 June 2007)

"Lebanon's ‘14 March': from protest to leadership" (1 April 2008)

"Lebanon's elections: reading the signs" (12 June 2009)

Thirty years, twenty years

Now, the moment of 2009 presents a new and far more serious challenge to the revolutionary state's legitimacy. There are multiple ingredients: a severe economic crisis, the arrival of a fresh and open-minded United States president whose persona dissolves the image of the "great satan", the arrival of a young post-revolution bulge armed with the tools of globalisation (above all, the mobile-phone). Indeed, the regime's relentless attacks on globalisation as a new conspiracy of the satanic west makes it appear that what is happening in the streets of Tehran is also globalisation's revenge.

The fact that "western" means of communication have become a key way of coordinating the protests raises two larges question about Iran's immediate future. First, just as the Iraq war and the Bush threat were used to subdue successive waves of protesters in Iran, will the nuclear issue be used to restrain the current wave?

Second, is Iranian society in the process of creating a new and vital movement that offers the prospect of change from within (thus departing - as in 1979 - from the Arab model, where change is expected to come - if at all - only from the outside)? If, and it is a very big if, the Iranians manage at the end of this process to topple their regime and avoid a civil war, they would achieve the historic feat of creating the first revolution for freedom and democracy in the middle east and the Islamic world.

If - that word again - the Iranians avoid the fate of their Chinese counterparts at Tiananmen Square in 1989, it will be in part because Iran has the capacity to reproduce a key element of the changes experienced by witnessed by the Soviet-bloc countries in the late 1980s-early 1990s. There, a parallel to the Iranian-Arab contrast operated: communist totalitarian states were after all capable of generating change from within (whereas their Nazi counterparts required war launched from the outside).  The communist experience allowed for the appearance of leaders such as Imre Nagy (Hungary, 1956), Alexander Dubcek (Czechoslovakia, 1968), and Mikhail Gorbachev (the Soviet Union, 1985) - all of whom unleashed a process that was carried on and crowned by the people. True, these figures were destroyed or bypassed, but 1989 witnessed the cycle in full. Iran is a country where this pattern of alliance between reformist leaders and popular mobilisation is seen again and again.

A source of optimism here is that thirty years - notwithstanding Fred Halliday's argument - constitute a long period for totalitarian regimes (see Fred Halliday, "Iran's revolution in global history". 2 March 2009). Nazism in Germany lasted only for twelve. Mao's China was by 1979 under the leadership of Deng Xiaoping turning towards economic freedom and a rejection of classic communism (if not yet in the political sphere). Joseph Stalin's Soviet Union was offered the gift of expanded control by its defeat of the Nazis in 1947, which only postponed the ultimate reckoning.

Now, Ayatollah Khamenei and his "Revolutionary Guards" are facing the choice of whether and for how long they are prepared to crush those who are contesting their and their revolution's legitimacy. Even if they are so determined, the Iranian people who have grown up under and around them may have ideas of their own about Iran's future.