Ali Ansari: The President needs to know the eyes of the world are on him

For Western policy-makers, this makes for a peculiarly Iranian election where the apparent decisiveness of the victory has only reinforced the ambiguity of the situation.

To date, Western governments have resisted the temptation to comment, other than to acknowledge the dynamism of the political debate, at least over the past few weeks. Thankfully, the White House avoided indicating any preference for a candidate, and there was refreshingly little talk of a "velvet revolution", which would only have been grist to the mill of hardliners eager to crack down.

Instead Western governments have maintained a dignified silence while at the same time making clear that they were watching with interest. It remains important, after all, to know with whom you will be seeking to engage, and to some extent Ahmadinejad's apparent re-election offers all the reassurance of familiarity. But there must at the same time be some anxiety that with such a result behind him, he will be even more verbose and self-confident than normal. Even more so because this electoral mandate will be widely regarded, by Iranians themselves, as fraudulent. All this does not bode well for the prospects of engagement.

And it is going to require some delicate diplomatic footwork. The truth is that for all the desire of Iran's political establishment to complete this electoral process and confirm Ahmadinejad's re-election, this process appears to have some way to go. There is clear discontent and no little anger, not only among the electorate but across the political elite, some of whom had to bear the brunt of Ahmadinejad's accusations last week. Ali Akbar Hashemi Rafsanjani, the powerful chairman of the Expediency council, has already served notice that he intends to sue the President for libel.

But far more serious is the discontent spreading on the streets. With people battling riot police in Tehran and the possibility of unrest spreading to other cities there is a clear crisis of legitimacy surrounding these elections.

Far from clarifying the situation and making things easier, President Obama and other Western leaders face a crisis entirely of Iran's making. Should they acknowledge the developments as imperfect as they are and negotiate with a government widely considered as illegitimate by its own people? Much will ultimately depend on the actions of Iran's new official opposition and the popular support they can muster.

If they compromise or dissipate, as the current leadership surely expects, and an air of normality returns to the country, there is not much that the West could or indeed should do. But if the opposition grows and becomes more vocal, and if this election becomes stained with blood, the West would do well to sit up and take note.

For the immediate term at least, discretion may be the better part of valour, but those in charge in Iran at the moment would do well to know that the world is watching, and watching closely.

Professor Ali M Ansari is director of the Iranian Institute at the University of St Andrews