Bub,
Unless international governments gain concrete proof of the massive fraud--which will likely be covered up by Iran's rulers--they will likely be very cautious in their pronouncements. On one hand, they would like the will of Iran's people to be respected. On the other, if they align themselves against the present Iranian government and that government prevails, they may wind up having cut off all negotiating opportunities on the nuclear issue on account of their opposition. Those are difficult trade-offs.
The conservative clerics (Ayatollah Khamenei and the Council of Guardians) and the Ahmadinejad government are ruthless. They won't go quietly.
If Iran's people attempt to bring down the government--via large protests or even violence--one can expect the Revolutionary Guards, secret police, and other security elements to resort to widespread repression and terror. In a "reign of terror" type situation, opposition leaders, student leaders, and others that the regime finds hostile or suspect opposes it will be dealt with severely.
In the end, if the protests continue to spread, as has been reported this evening, the government will probably give an ultimatum and then move to quash the protests.
It is unfortunate that the will of Iran's people will likely be violated and ignored. But the unelected and unaccountable conservative clerics care little about the will of the people. Their major priority is retaining power.
Hence, I don't believe the protests will escalate to the point of a new Iranian revolution, much less one that would bring down the conservative clerics and Ahmadinejad. The risk of such a revolution might increase if the regime acts ruthlessly against peaceful protests leading to widespread deaths and/or injuries. Then, a more explosive situation could be set off.
