What are you talking about? We've done nothing but talk to them for years. That and the odd embargo. But nobody is going to war with Iran. They are going to get the bomb and the middle east is going to get that much more unstable. The US is not going to invade anybody over owning a nuke. But it will be more common for others in the middle east to want one. And that is probably going to happen.
The countries in the middle east aren't particularly worried about the Israelis having a nuke, they've had one for decades. No problem. But the Iranians are making them nervous. An Iranian Nuke gives power to a people with a long history of running the show in the middle east. The West has a tendency to come and go in the middle east and the Arabs know it. But the Iranians (Aka, the Persians of Antiquity) have been around a lot longer, been in control of that area way longer and kind of look at the middle east as their own back yard.
Bush is gone and the US is not going to do anymore than the UN minimum until mushrooms sprout somewhere.