A day to ask why we still need the bomb

THE atomic bomb that was detonated over Hiroshima 50 years ago today, and the second one which destroyed Nagasaki three days later, were not exclusively American creations. The Manhattan Project which produced them owed its inspiration in large measure to work conducted in Britain in 1940 and 1941, before the United States entered the war. A small number of British scientists subsequently went to America to help to complete the work, and they made important contributions to the bomb design. The existence of this nuclear partnership, however unequal, was acknowledged when President Truman sought and received British government consent before using the new weapon. It is as well to remember this as we reflect on the terrible consequences - the hundreds of thousands of bodies melted by heat, or bloated and poisoned by radioactivity, or simply turned to dusty shadows on the ground. Britain shares the responsibility.

Britain, we know, went on to become a nuclear power in its own right, and it remains so today. The latest instrument of this power is the Trident missile system, now progressing towards full deployment. The price for Trident, most of which has already been paid, is expected to be pounds 11.6bn. For this we will have four large submarines, each capable of carrying 16 missiles. Each missile can deliver up to eight bombs, each of which can be programmed to strike a different target. Each bomb, it is believed, will have the destructive yield of approximately seven Hiroshima bombs. In practice all this destruction could not be wreaked at once, but at a conservative estimate Trident should be capable of levelling 50 or so cities in a day. This is an extraordinary power, and this is the moment to ask whether we need it.

Trident had already been ordered when the world marked the 40th anniversary of Hiroshima, 10 years ago. Then, the arguments about the British nuclear deterrent were quite different. The arms race was in full cry. The Soviet Union still existed in all its might and, although Mikhail Gorbachev had recently taken charge, no one foresaw the collapse that was to come. Ronald Reagan was in the White House, fearing the evil empire and planning to plough billions of dollars into Star Wars. The deployment of cruise missiles to Europe was under way. From that perspective, Hiroshima was widely viewed as the first step on a journey that seemed likely to end with the destruction of the planet.

In August 1995 the world, in strategic military terms, is scarcely recognisable as the same place. With the Soviet Union gone and the superpower arms race now proceeding in reverse - weapons are being destroyed - surely Britain does not need such a big stick to wave. It would be wrong to suggest that the Government has been unresponsive to the new atmosphere. The last British free-fall nuclear bombs are to be scrapped in 1998. The Navy's tactical weapons have already gone. A plan to buy a new nuclear missile system for the RAF has been dropped. And it was announced this year that Britain was no longer producing fissile material for use in warheads. Trident, however, will remain, and as we have seen, its potential power is sufficient to render these other steps insignificant.

Two practical reasons are put forward for keeping Trident despite all that has changed. The first is that the threat from the old Soviet Union may only be dormant, and it would be imprudent to disarm before we know that it will not arise again, perhaps in the form of a fascist Russia. The second is that in a world where any number of "wildcat" states may be trying to acquire the atom bomb, Britain may in future need nuclear weapons for use against another country. This is a very weak case indeed. Both arguments beg the question: why Britain? There is no reason to suppose that, if either threat became a reality, Britain among the world's nations would be especially liable to attack. Germany or Poland would be much more vulnerable to bullying or invasion by a fascist Russia, and yet no one is saying that they should have nuclear weapons. Iraq, Iran and North Korea all have many more immediate potential adversaries than Britain, but does anybody suggest that their neighbours need Trident?

The only reason that Britain has nuclear weapons today is that, unlike these other countries, it had them in the past. When Clement Attlee decided in 1947 that Britain should make an atom bomb of its own, this country had just triumphed in a world war, the Soviet threat was all too clear and there was still a British Empire to protect. We were still a big power, and the idea of forgoing nuclear weapons was never seriously entertained. The link with that world was broken when the Cold War ended. Having joined that confrontation to stand shoulder to shoulder with the United States, Britain stayed until the business was finished. But Britain will never enter any future conflict on the terms under which it entered the Cold War, and nobody would expect it to. Even with Trident its shoulder, in military terms, no longer reaches America's waist.

And the British nuclear deterrent is not just an anachronism; it may be dangerous. It undermines the case for other countries to refrain from making bombs - why should they not, if we can? - and it provides an incentive for proliferation. So long as nuclear weapons appear to confer prestige or influence, vain tyrants everywhere will want them.

The case for scrapping Trident is strong, and getting stronger, yet there is a strange silence hanging over the issue. Even on this anniversary of nuclear carnage, it is not being vigorously debated. Why? Perhaps because there is no pressure from the Labour Party - the disaster of 1980s unilateralism is too fresh in the memory. More is the pity, for it means that both Government and Opposition are prisoners of the past.