Sir

We welcome your Editorial (“Conscience call” Nature 432, 421; 2004 10.1038/432421a), calling for active engagement by scientists in addressing the problems of nuclear-weapons proliferation. But the ‘solution’ proposed by C. P. Robinson of the Sandia National Laboratory in his Commentary article, “Revisiting the Baruch Plan” ( Nature 432, 441–442; 2004 ), is an unlikely route to safety. He suggests more military alliances, each with a nuclear umbrella state providing ‘security’, forming a worldwide network of nuclear deterrence.

Would it not be more effective, and safer, to build alliances of nuclear-weapons-free countries? There are already several large and legally recognized nuclear-weapons-free zones (NWFZ). These include the areas covered by the Treaty of Tlatelolco in Latin America, of Rarotonga in the Pacific, of Bangkok in Southeast Asia and (yet to enter into force) of Pelindaba in Africa. Some states, including Mongolia and New Zealand, have individually declared themselves nuclear-weapons-free. Proposals have also been made for NWFZ in central Europe and the Middle East.

These treaties or decisions bind their adherents to non-nuclear policies. Some are recognized by the nuclear-weapons states, which agree not to use nuclear weapons against countries in the NWFZ.

If, as Robinson suggests, most or all states were linked to nuclear military alliances, this would render them all liable to nuclear attack. NWFZs will tend to reduce the proliferation of nuclear weapons, and simultaneously make such countries safer by diminishing the overall likelihood of nuclear conflict.

In our view, the way forward is to treat nuclear weapons like other weapons of mass destruction (WMD), which have all involved scientists in their development. Chemical and biological weapons are forbidden by treaty. There exists a model Nuclear Weapons Convention, introduced into the United Nations in 1997 by Costa Rica. Its entry into force would end the hypocrisy of the nuclear-weapons states lecturing other countries for their nuclear ambitions. All WMD would be forbidden; there would be no need for WMD-dependent alliances; the entire globe would be a nuclear-weapons-free zone.