Pious resolutions won't rid the world of the threat of nuclear war

Nuclear disarmament is back, and this time it is "unequivocal". The world's five long-standing nuclear powers, the United States, Russia, China, Britain and France, have put their names to a statement promising to get rid of all their nuclear weapons, but without saying when.

Nuclear disarmament is back, and this time it is "unequivocal". The world's five long-standing nuclear powers, the United States, Russia, China, Britain and France, have put their names to a statement promising to get rid of all their nuclear weapons, but without saying when.

This is, sadly, the kind of agreement that gives diplomacy a bad name. The statement came at the end of a conference to review the Nuclear Non-Proliferation Treaty, or NPT, and it certainly marks a step forward from the wording of the original treaty in 1970, which only committed signatories to move "in the direction of" nuclear disarmament.

However, universal nuclear disarmament has been a theoretical objective accepted insincerely by all national leaders for decades. The "complete elimination of nuclear weapons" was affirmed as an "ultimate goal" by the last five-yearly review of the NPT in 1995. So what is different this time? That it is "unequivocal"? Does that mean the pledge was equivocal five years ago? We scurry to our dictionary. "Equivocal: subject to two or more interpretations and usually used to mislead or confuse; uncertain as an indication or sign." That, unfortunately, is still a succinct criticism of last weekend's agreement.

It could be argued that diplomacy works by agreeing goals and then forcing countries to face up to the practical steps required to achieve them. That was the principle of the agreement on climate change at Kyoto in 1997. But there the objective - of reducing emissions of greenhouse gases - was backed by a consensus, even if some of the politicians who lent their countries' names to the agreement may not have been genuinely committed to fulfilling their obligations. The objective of total nuclear disarmament, however, will not be achieved so long as it excludes some nuclear powers, most notably Israel, India and Pakistan. So long as one other country has the potential to make and use nuclear weapons, it makes no sense - as the unilateral disarmers discovered in this country in the Eighties - for any country to give up altogether its own nuclear capacity.

There are, meanwhile, plenty of more realisable objectives in this field. The original aim of the NPT, to prevent proliferation, is still valid. The argument that it can only be achieved if existing nuclear states promise to disarm is a counsel of despair. There is much work to be done on preventing the development of nuclear weapons by terrorists. A complete ban on the testing of nuclear weapons is another worthwhile and achievable objective. The Indian and Pakistani tests two years ago underlined the urgency of achieving it, and it is bitterly regrettable that the United States Senate refused once again to ratify the Test Ban Treaty last year.

It may be that - ultimately - total nuclear disarmament is an achievable goal. The development and use of chemical and biological weapons has, after all, been suppressed by international agreement. But that requires more progress on the lesser-order objectives and, above all, more countries to sign up to a global regime of nuclear weapons control.

The fact that the United Nations conference last weekend could only come up with a reheated promise of deferred virtue, however "unequivocal", suggests that it made depressingly little progress towards the objectives that really matter.