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.

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

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.

More likely, there were probably some real divisions within the Iranian government - some groups wanted to ally with al Qaeda against us, others didn't want to have anything to do with that. So I think that debate resulted in no decision being made for awhile. The problem was they left the al-Qaeda folks in Iran in the hands of their intelligence services and Revolutionary Guard, who didn't really keep an eye on them - and may not have kept an eye on them on purpose.

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.

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.