So by virtue of the destruction nuclear weapons wrought in Japan, using such weapons has become impossible?

There were definitely some long-term results from the use of the A-bombs in Japan. One president after another and one leader of the Soviet Union after another looked at the destructive force of these weapons and made a private decision that there is no context in which they could ever be used. We came very close a number of times during the Cold War, of course. But sense prevailed.

Was physicist Niels Bohr right in arguing that the only way to control nuclear weapons is to make the technology open to everybody?

Bohr's idea was that if nations forwent developing a nuclear arsenal, then they would receive assistance in developing civilian nuclear technology -- an idea that is more or less in place today. But Bohr was really trying to make clear to the political leaders of the time that there was no way these weapons could be used once more than one nation had access to them. That's how it turned out. But Bohr also thought that once nations realized this salient fact, they would forgo the arms race.

It doesn't seem like too many people were listening to him.

These weapons still have lots of prestige as a symbol of national power. This attitude follows very directly from the continuing insistence on the part of the United States to this day that other nations shouldn't have nuclear weapons but we should because it's important to our national security. If we can make that claim, then so can any other nation or any other entity. And they have. A country like North Korea knows -- especially after the invasion of Iraq -- that being part of the "Axis of Evil" is a dangerous place to be. Because we insist on our primary right to be a nuclear power, they have no other option but to do the same.

Is disarmament a realistic goal? Can we turn back the clock?

It is possible to imagine a world without nuclear weapons, but the know-how would still be around and deterrence would still work. You only have to imagine it as extending the amount of time it takes to deliver a weapon to its target. Today it takes 15 to 30 minutes to deliver a nuclear weapon, which is hardly enough time for any kind of rational consideration. If you took the warhead off all the missiles and kept them in a separate place -- which is how Pakistan maintains the security of its weapons -- then it would take perhaps an hour or two hours. If you actually dismantle these weapons and put the parts in separate places, it would take three days. The countries like Germany that have the technology to go nuclear but have refrained from doing so have a delivery time of about a year. In such a world, if one country decides to start building a weapon, other countries might follow suit. At worst, that would bring us right back to where we are today.

How great is the danger that a nuclear weapon will be used again?

Everybody I talk to in the nuclear community is pretty comfortable that nation-states are not going to use nuclear weapons -- even states like North Korea are clearly more concerned with the prestige factor than about actually using it. But everyone I talk to is greatly concerned about the very real possibility of a terrorist nuclear attack. Terrorist groups -- al-Qaida is one example -- would see a great amount of prestige if they were able to build and detonate a nuclear weapon in New York City or in Iraq's U.S.-controlled Green Zone. In fact, everyone I take seriously in this field believes the possibility is 100 percent. The fact is, if you can get a sufficient quantity of highly enriched uranium, it's very easy to make a nuclear weapon that would explode with about the same yield as the Hiroshima bomb. These weapons are so small and so portable and so vastly destructive for their weight and size that there is no effective defense against them except abolition.

- - - - - - - - - - - -

This article has been provided by Der Spiegel through a special arrangement with Salon. For more from Europe's most-read newsmagazine, please visit Spiegel Online at http://www.spiegel.de/ international or subscribe to the daily newsletter.

Recent Stories