THE PLAIN DEALER

08/06/03

Fifty-eight years ago today, the United States dropped the first atomic bomb on Hiroshima, incinerating the city and its inhabitants. Shortly after that, it destroyed a second Japanese city, Nagasaki, with a second nuclear weapon. The horror of these events was so great that, thankfully, in the intervening half-century or so, no nation has used nuclear weapons against another nation.

During the Cold War, the policy of "mutually assured destruction," appropriately nicknamed MAD, effectively kept nuclear peace. The United States and the Soviet Union had amassed so many nuclear weapons (more than 40,000, enough to destroy both countries many times over) that each knew that use of such weapons would be followed by a retaliation too deadly to contemplate.

In spite of this policy, there have been times when the world seemed on the brink of nuclear war. The Cuban missile crisis, for example, spurred the construction of home bomb shelters and ridiculous and traumatic civil defense exercises in which school children practiced hiding under their desks.

In 1947, the Bulletin of the Atomic Scientists created the Doomsday Clock. On that date, the clock read seven minutes to midnight, as a dramatic visual representation of how close the world might be to nuclear disaster.

The Doomsday Clock has been moved forward and backward 16 times since its creation, coming as close as two minutes to midnight in 1953 after the United States and Soviet Union tested their first thermonuclear weapons, and to three minutes to midnight in 1984 with the acceleration of the arms race induced during the early years of President Ronald Reagan's administration. At the end of the Cold War, after the Strategic Arms Reduction Treaty was signed, the clock was moved back to 17 minutes to midnight, representing the lowest level of perceived nuclear threat since its inception.

In February, the board of directors of the Bulletin moved the clock forward for the third time since 1991. It now reads 7 minutes to midnight, the same reading it had in 1947, at the beginning of the modern nuclear arms race. They were motivated to make this move in part because of the U.S. abandonment of the Anti-Ballistic Missile Treaty, and U.S. efforts to thwart international agreements to constrain proliferation of weapons of mass destruction.

Unfortunately, current events are likely to drive the clock even closer to midnight. It is true that events in Iraq suggest it was not undertaking an ambitious nuclear weapons program, as we had been earlier led to believe. However, North Korea has made it clear that it is actively developing nuclear weapons and might export them.

The new concerns about nuclear proliferation come not just from developing countries, however. In a recent disturbing move, the Bush administration announced its intent to begin research on a new type of nuclear weapon, a bunker buster that might destroy underground bunkers. It is claimed that such "small" nuclear weapons would have little collateral damage, and therefore their use might be sanctioned in an attempt to locate and destroy enemy or terrorist weapons sites located underground.

Unfortunately our recent experience with pre-emptive strikes against purported enemy locations in Iraq, Sudan and elsewhere suggests that military intelligence is not what we might hope it would be, and that civilian targets can easily be confused with military ones. Moreover, breaking the taboo against the use of nuclear weapons in wartime is a very dangerous precedent to set, and one that should not be taken lightly. In particular, it is not at all clear what kind of strategic advantage small nuclear weapons might have over large conventional weapons for this type of military purpose.

The United States is not the only major power exploring a new generation of nuclear weapons. Recent reports from Russia suggest an active program to replace aging weapons and develop new ones. At a recent conference in Moscow organized by the Washington-based Center for Defense Information and the Russian Ministry of Atomic Energy, researchers confirmed that significant funds were being allocated to new nuclear weapons research.

The deaths of hundreds of thousands of people in Hiroshima and Nagasaki should continue to serve as a stark reminder that the world should work together to keep nuclear weapons from ever being used again. If we attempt to change the ground rules so that some nuclear weapons are acceptable for first use in wartime, we risk sliding down a slippery slope from which we may never recover.

Krauss is chairman of the Physics Department at Case Western Reserve University. His most recent book, "Atom," won the American Institute of Physics Science Writing Award in 2002.

© 2003 The Plain Dealer. Used with permission.