What happens in Iran matters hugely. It is the superpower of the region, with a considerable reach - as the only theocratic Islamic state - beyond its borders. There is no doubt that the West would have preferred the more emollient Mousavi to existing president Ahmadinejad, and western countries have been muted in their reaction to Ahmadinejad's re-election victory. But we should also be careful of reaching simplistic conclusions. Whoever is president, the real power lies with Supreme Leader Ayatollah Khameini and the clique of conservative clerics who dominate the Guardian Council. For all his bluster, Ahmadinejad's powers, particularly in foreign policy, are limited, as would Mousavi's have been. The Islamic Republic is governed by the revolutionary victors of 1979, and they retain a curious mixture of pragmatism dosed with heavy anti-western rhetoric.
John Simpson reports that the supporters of either side remain remarkably good-humoured towards each other, despite the violence which is mainly based around confrontation with the forces of the establishment. He also says we may never know the exact result of the Iranian election. But Mousavi is not being very explicit - so far - in his allegations of fraud (and he is an old political warrior unlikely to take defeat lying down); previous elections have been regarded as fair; Ahmadinejad has genuinely high levels of support and we should be cautious before accepting that over 10 million votes could have been fraudulently cast.
This is not another revolution, and many of those imprisoned have now also been released pretty swiftly. This is, possibly, another step in the Islamic Republic's march towards political maturity. It may be that the state has acted out of panic rather than out of a concerted bid to crush the reformers, and that what is in fact a quite diverse political establishment may well continue to generate debate in this fascinatingly evolving nation.