Did it stop Iran from creating a nuclear program? No. Did it allow for a change in government? No.
Mainly the people who suffered most were the common people of Iran. The government in Iran took advantage of this situation to radicalize people against the US even more.
It has stopped their nuclear program - see the news. More specifically, it didn't make it impossible for them to build nukes, but it motivated them to stop in order to get the sanctions relieved.
(Of course we all are talking speculativly, unless a someone very high in the Iranian government, who knows their motives, is posting on HN.)
This is very US centric but still interesting. http://iranprimer.usip.org/resource/green-movement
>The Green Movement reached its height when up to 3 million peaceful demonstrators turned out on Tehran streets to protest official claims that Mahmoud Ahmadinejad had won the 2009 presidential election in a landslide. Their simple slogan was: “Where is my vote?”