The three opposition candidates are saying that they will not accept the result. But it is unclear whether they will be able to mobilise their supporters to seriously challenge it.
Regardless of the result of this election, Iran was going to continue to pursue its nuclear ambitions and its attempt to become the dominant power in the region. With Ahmadinejad as president, it will probably soon become apparent that diplomacy will not persuade Iran to give up its nuclear programme. At that point, America and its allies will have to decide what they are prepared to do to stop Iran from becoming a nuclear power.