1. Iran with nukes would be a bad thing.  I don't care about arguments that condemn the hypocrisy of trying to not allow Iran to have them. It is a regional power that is hostile to both the US and Europe, letting it be more powerful would be bad for the interests of both the US and Europe.

2. We don't know whether Iran wants nukes or not.  Quite possibly they don't either. What we do know is that they have a program that could serve as the basis for nuclear weapons development and that they seem to be intent on at least keeping their options open.

3. Assuming the intelligence reports are correct Iran is nowhere near actually having the capability to produce its own nuclear weapons.

4. Under the current Supreme Guide Iran has been quite pragmatic and rational in pursuing its own national interests - witness its cooperation with the US against the Taliban and in creating the Karzai government.

5. The new president seems less inclined towards pragmatism - more a reversion to the messianic revolutionary spirit of the early Islamic Republic.

6. Even someone sympathetic to the foreign policy ideology of the current US administration would have to admit that its competency leaves a lot to be desired.

1. Slowly build pressure on Iran, with slowly being the operative word. Thus the referal to the Security Council, but the vague verbal rebuke that is the most that China and Russia are likely to allow is actually just the right step for now.

2. Later perhaps low level sanctions - e.g. an EU travel ban for senior Iranian officials and their families.  Such sanctions could be gradually ratchetted up over a period of years.

3. Don't do anything major until this admin is out of office.

I often read that a military attack will be necessary since the Chinese and Russians won't support a full blown sanctions regime in the Security Council. But nor would they support a resolution allowing military action. If the US is not concerned about having its military actions being legal, it could just as easily block Iranian exports as it could bomb its nuclear program related sites. Now, considering the situation of the oil markets such sanctions would pose their own problems but that's true of both UN sanctions and a unilaterally imposed embargo.