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.

It is unimaginable that the United States would have to contribute hundreds of billions of dollars and highly unlikely that we would have to contribute even tens of billions of dollars.

The basic problem with the Non-Proliferation Treaty is there's no teeth in it, no penalties for countries that don't comply. Worse, as you say, the very naïve structure of the NPT has actually made it helpful for countries who want to acquire nuclear weapons. Iraq, North Korea, Iran, all used the NPT to build up their nuclear programs.

Our support for the Shah, the CIA coup in 1953 - has become infused into the Iranian political discourse. The regime that came to power in 1979 during the Iranian revolution actually defined itself as anti-American, and that's now a critical ingredient in the Iranian domestic political debate. That really is the source of our problems - the regime in Tehran continues to see itself as opposing the US. In their eyes, everything the US does is directed at them in a very malevolent way, and therefore they have to fight back against it.

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.

Most Iranians are sick and tired of revolutions. They've had one for the last 25 years, and they don't want another one. Those who've tried to spark another revolution have failed time and again. I don't think there's any evidence that somehow, if the U.S. gave these guys the high sign, it would make regime change somehow more likely. Every time the U.S. has tried to interfere in Iranian affairs to help a particular group of Iranians, it's backfired on us, and hurt the group we tried to help.