Q: Now that we have cracked the Pakistani nuclear weapons ring that was providing technology to North Korea and Iran, Libya has come around, and Iraq is no longer a threat, are you beginning to feel less concerned about the spread of weapons of mass destruction?
A: Are you kidding? I'm sure there are other countries out there with secret WMD programs. This is still one of the things I'm most concerned about.

Q: So, does this discovery that Pakistani scientists were evading international arms control inspectors make you feel that we should give up on trying to solve this problem through arms control, and rely instead on the threat of using military force against countries that develop weapons of mass destruction?
A: No. But we should give international inspectors more power to go wherever they want to make sure that people are not developing them.

Q: If we do that it would mean that the international inspectors could be poking around U.S. biological laboratories. Aren't you concerned that countries could learn commercial secrets, or that they might learn things about our counter-bio-terrorism research?
A: Where do you get these weird arguments? I can't believe anyone in the U.S. government takes them seriously. Obviously -- it's more important that we get to look around other people's laboratories! But if we put pressure on countries like Pakistan to let in inspectors, this might lead to a backlash in Pakistan so that it will not cooperate with us in the hunt for al Qaeda. I think arms control is just too important. We can't back away from that.

Q: Do you think the U.S. should ratify the Comprehensive Test Ban Treaty?
A: Yes, of course. Haven't we?

Q: Well, there is concern that this could limit development of U.S. nuclear weapons.
A: I don't find that very convincing. I think we should probably aim to get rid of nuclear weapons eventually, not develop new ones.

Q: Incidentally, did you know the U.S. has committed to doing that as part of the treaty to prevent the proliferation of nuclear weapons?
A: No, I didn't. But that sounds good. We should probably try harder to do that, though of course we have to do it together with other countries, so we can be sure that everybody else is disarming too. That might take a while. But for now it makes sense to me that if we want other countries to not develop nuclear weapons, we shouldn't be making new and improved ones for ourselves. It might even make sense to clearly promise non-nuclear countries that we will not use nuclear weapons against them -- I mean, if we don't want them to build nuclear weapons.

Q: But don't you think that with the threat of chemical and biological weapons, the U.S. should have nuclear weapons there as a means of deterring their use?
A: No. That doesn't make sense to me. I don't think we should ever be the first to use nuclear weapons.

Q: So, do you like the idea of the U.S. and other nuclear powers reducing the number of nuclear weapons kept on high alert?
A: Sounds like a no-brainer to me.

Q: It seems you don't think nuclear weapons should play such a big role in U.S. defense. How many nuclear weapons do you think the U.S. needs to make sure other countries are deterred from attacking it?
A: Oh, I think about a hundred should be enough. I realize that would probably mean a cut below what we have now. We probably have, what, about twice that number?