What do you think is the most worrisome development in terms of nuclear weapons today?
I think the most acute questions are the negotiations with North Korea and with Iran. I'm favorable to the approach that's been taken lately by the U.S. in relation to North Korea. I don't think that threatening the North Koreans with any military action is a defensible policy. Military pressure is more likely to be counterproductive and lead them to a hardening of their positions; that's what we have seen in the past. However, the six-power talks in Beijing have been looking much more for carrots, and including, notably, a guarantee against attack, and also a guarantee of diplomatic relations with the U.S. and with Japan, if the North Koreans go along with a nuclear settlement. I think this is much more likely to yield results.
In the case of Iran, I think that while the Europeans have a number of carrots on the table, they say that these carrots are only available to Iran if, first, Iran does its part. There's a precondition that Iran should suspend enrichment. I don't know any negotiations in which one party says, yes, I will do my part and then we'll discuss what you'll give me for it. But the two elements I mentioned in the case of North Korea are not, to my knowledge, on the table in the case of Iran. Namely, a guarantee against attack, and talk about diplomatic relations. So I think that playing these two cards would be enormously valuable.
What about the possibility of nuclear weapons falling into terrorist hands?
One can hardly exclude any risk, but most experts deem it highly unlikely that non-state actors would be able to master this. They have to put together the weapons; they also have to find some means of delivery. And we also know from the case of terrorists in Tokyo a number of years ago that they chose rather the chemical weapons in their attack in the subway. There's some talk about what they call dirty bombs, a way of using radioactive material and exploding it and contaminating an area. That would be a terror weapon, but can by no means be compared to a nuclear weapon.