Sir

We are glad to see that Nature is taking a strong line about the growing dangers of nuclear proliferation (“We have the technology” Nature 432, 432–437; 2004). When the Berlin Wall came down it was easy to become complacent: most people believed that the dangers of nuclear weapons had receded. That has proved overoptimistic. Nature is right to point out that the increasing number of states possessing, or on the point of possessing, nuclear weapons gives grave cause for alarm. We strongly support the view that scientists have a special responsibility to restrain these trends.

In his Commentary in the same issue, C. P. Robinson (“Revisiting the Baruch Plan” Nature 432, 441–442; 2004) takes the view that the nuclear non-proliferation treaty (NPT) is not the right tool with which to tackle this problem because of its “basic structural problems”, which he says the world is not yet ready to address. He proposes, instead, a gradual strengthening of regional alliances. This should be given careful consideration. But let us not forget that the original nuclear powers, when they signed the NPT, made an “unequivocal undertaking to accomplish the total elimination of their nuclear arsenal”. We believe that the right approach is for the nuclear powers to abandon those policies that are incompatible with the letter and the spirit of the NPT.

For example, Robinson's claim that “The United States has been leading an international effort to reduce existing nuclear stockpiles, including its own” is not supported by talk of new ‘bunker-busting’ nuclear weapons. Congress has denied funds for 2005, but the administration has renewed its request for 2006. Furthermore, the administration has affirmed — in its “National Strategy to Combat Weapons of Mass Destruction”, December 2002 — its willingness to use pre-emptive measures against WMD-armed adversaries (a course contrary to Article 2(4) of the UN Charter) and to respond to an attack with overwhelming force, including use of WMD.

We believe that the failure of the official five nuclear states to abide by their NPT obligations encourages proliferation, by providing an excuse for other nations to acquire nuclear weapons. The United Kingdom, for example, should phase out its ‘independent’ nuclear weapons, such as Trident submarine-based systems.

Robinson claims that the United Nations “is not now an organization that can satisfactorily demonstrate security leadership”. The United Nations must be brought up to date, but that can only happen with US support and US willingness to take a less self-centred and more global view than it is doing at present.