Once Iran gets nuclear weapons, they may believe that they are no longer vulnerable to either.

I think if you could remove all of the baggage - all of the ideology, the history, whatever else - and look in purely geostrategic terms, I think it's hard to figure out why the US and Iran would necessarily be in conflict. In fact during the shah's era, before 1979 - recognizing that there were all kinds of other problems - the US and Iran worked together splendidly at the strategic level.

Once Iran gets nuclear weapons, they may believe that they are no longer vulnerable to either.

The Iranians are very skilled terrorist, and we'd have to expect that they'd hit at us as hard as they could. Especially in Iraq, where they have a great deal of power and influence.

The real concern is that Iran would do what Pakistan did. Pakistan wanted nuclear weapons, like Iran, purely for defensive reasons - to defend itself against India. The problem was that once Pakistan acquired the weapons, it allowed the country to be more aggressive. So they stepped up their support for the Kashmiri terrorists, and it led very quickly to the Kargil crisis in 2000, which almost sparked a nuclear war between India and Pakistan.

The US has just consistently tried to ignore Iran. And this is ironic because the Iranians believe that the United States is as obsessed about them as they are about us.

Iran uses terrorism very instrumentally as an element of foreign policy; they are not just intent on just killing as many people as possible, like al Qaeda. There's no reason to believe that would change.