An anniversary that exposes the fractures in Iran

Twenty-two Bahman, the anniversary of the founding of the Islamic Republic, kept its promise. Hundreds of thousands of supporters of the Iranian regime poured into the main square of the capital Tehran - some reportedly bussed in for the event - to show their determination to protect Khomeinist ideals and cheer the speech of their hero, the president Mahmoud Ahmadinejad, who displayed typical defiance and bombast for over an hour. He celebrated the scientific and economic achievements of his country and, in a move certain to anger many abroad, announced that Iran had produced its first batch of uranium enriched at 20 per cent. This was certainly the image that the regime wanted to project at home and abroad.

A few blocks away, however, the scene was very different. Similar numbers of protesters, who unlike the regime's supporters faced checkpoints and intimidation, gathered to voice their dissent and discontent on that most symbolic day. The opposition, battered yet relentless, has decided to challenge the regime on its own ground and deny its popular as well as symbolic legitimacy. In the streets and in the metro of Tehran, but also in provincial cities like Tabriz and Isfahan, calls for the ousting of Mr Ahmadinejad competed with demands for a referendum on the future of the Islamic Republic. Reports of clashes were numerous.

This was not the image the regime wanted on TV screens, and it did all it could to subdue the opposition. On top of the massive deployment of security forces and the unsurprising arrest and bullying of opposition leaders, including Mehdi Karroubi and Mohammad Khatami, authorities shut down Gmail inside the country and tried to impede internet access, as well as limiting journalists so they could only cover the pro-government rally.

The regime is far from being in its last throes: as demonstrated yesterday, it can mobilise vast numbers of supporters and can certainly put up a fight. The security forces are still mostly loyal, though in many cases they have been unwilling to use brute force. And the opposition itself is not united on the goals of reforming the system or regime change. But the popular mobilisation is not weakening, and fissures in the ruling establishment, though not fatal, are increasing. This should give pause to those who dismiss the Green movement as a fleeting phenomenon.

In this contest, no one seems to have the upper hand, but with its legitimacy and authority now under assault at every turn, the regime's promise to crush the opposition seems all but fanciful. Its survival depends on reaching a substantive political compromise that would sideline Mr Ahmadinejad and fundamentally reorganise the division of power within the country. Otherwise, the polarisation will cripple the country's economy and ability to reach a compromise with the international community on its nuclear programme and other activities.