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.

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.

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.

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.

In the United States, Iran is nothing but a whipping-boy. Few Americans have any real use for Iran. Most of us, what we know and remember about Iran are things like the hostage crisis in 1980, or they think about the Iranian attacks in Lebanon, or on the Khobar Towers. So you don't get a whole lot of political mileage in the United States by going out and advocating better relations with the Iranians.