The US played this episode about as good as it could have been played. Offer the peace deal. Use the proxy to punish for non-compliance (which was ironic given Iran's love of proxies). Hit their ability to produce undesired materials and avoid suitcase nukes being made for terrorists.
Key now is let's not get tied up in nation building. If the Iranians rise up that would be great. But they have to want freedom and fight for it themselves or it means nothing. Khomeni and his regime will go to the table at some point.
One difference in Iran vs Iraq or Afganistan is the Iranians are not too far removed from knowing what a western system feels like. They are a capable and intelligent people, so I am rooting for them to rise up but who knows how this thing will turn out.