This should have been a warning about Mousavi. After all, he had impeccable Islamic credentials. He and his wife were devotees of Ali Shariati, one of the Revolution's main ideologues. As Prime Minister, he was complicit in Tehran's clandestine nuclear efforts and the regime's brutal repression of its citizens. Even Mousavi would have pursued a nuclear programme. During the campaign, he did not criticise Ahmadinejad for doing so, but for drawing international condemnation on Iran's nuclear activities and its ballistic missile programme, which under the previous reformist President, Mohammad Khatami, Iran had been able to pursue without outside interference.

Still, the regime must have concluded, the unprecedented mobilisation for Mousavi alongside some of his utterances may bode ill for the Revolution. There is no precedent, after all, in the annals of authoritarianism, where an ideologically-driven dictatorship can pilot political change without losing control. When Iran found itself on that path under Khatami, it ended in a bloodbath. So the regime — now firmly in the grip of the Supreme Leader and the Revolutionary Guards — must have reasoned that it was foolish to take a risk. Better face public protests and international consternation than lose the plot. Having rigged the election and exposed the ruse about Iranian democracy to anyone apart from Iran's staunchest apologists and a few inside the Washington beltway, the regime will now feel no compunction about crushing any attempt to challenge the result. It knows that the price to pay for this exercise — when America is extending a hand of friendship and words of contrition — is infinitely lower than taking the uncertain road of moderation. I do not expect a Velvet (or "Green") revolution any time soon. Ahmadinejad may not be the last word of Iran's power structure. But he now represents the most articulate expression and the true face of its regime, what it wants to achieve in the world.

What does it mean for the international community and its hopes to find accommodation with Iran? All pretexts for inaction or laying in wait are now gone. It is a new day in Iran — one where Islamic radicalism has staked its sole claim to be our interlocutor. Let the diplomatic dance begin then. And woe betide those who think that such tidings may bring peace in our time.