I met a man called Neil Boyd, retired and living in York. He had painted in oils and watercolours some remarkable pictures from memory of his time as a prisoner of war in Japan.

Neil died a few years ago but I think of him especially this week, the 60th anniversary of the end of the war with Japan.

Neil was sent with the Army to Burma where he was captured. The Japanese stuck him in solitary confinement in a hole in the ground. Over this hole they placed a grille and, as they walked by, the soldiers repeatedly urinated and defecated on Neil underneath.

One day he was taken out and put on a train. It turned out that the train was bound for Hiroshima. Neil was in the city when the bomb was dropped and his recollections of what his fellow prisoners and his captors endured is beyond my telling. If you think you can bring yourself to read about it, get hold of Neil's autobiography, An Englishman's Peace and War, which is published by the Pentland Press.

I used to go round to Neil's house for a drink and a chat. He told me of his many trips back to Japan to ask the Japanese politicians to say sorry for the way they had treated him. He also repeatedly told me that he was glad the atomic bomb had been dropped on Japanese cities.

There is no doubt that the dropping of the A-bomb saved at least a million lives - those of Allied soldiers and sailors preparing to mount an assault on the Japanese mainland. The ending of the war, brought abruptly about by the bombs on Hiroshima and Nagasaki, also saved millions more Japanese lives, both soldiers and civilians.

The bomb was a terrible invention and no-one can disinvent it, but no doubt the evidence of its appalling destructiveness seen in Hiroshima has restrained the great powers from using it again.

Still, we are forced to listen to the ramshackle arguments of the unilateral disarmers who say that Britain should get rid of its stocks of atomic weapons because their possession makes it more likely an enemy will drop nuclear bombs on us. The Soviet authorities used to describe CND as "useful idiots" - and they were right.

It remains astonishing how many men with the reputation for intelligence - I do not say they actually were intelligent - supported unilateral nuclear disarmament. The last interview I heard with Robin Cook on Radio Four a few weeks before his death was an example of this foolishness. I could hardly believe my ears when he said that since the Soviet Union had collapsed 16 years ago we now no longer had any need to keep our nuclear deterrent.

Sixteen years, as Harold Wilson might have said, is a damn short time in politics. And a nation that collapses might rise up again. In any case, Russia still holds thousands of nuclear weapons which, in its present state of disintegration, is more volatile and unreliable than the old USSR ever was. The atomic bomb is a very nasty thing which ought never to have been invented. Given that it has been invented, it has saved more lives than it has destroyed. We should keep our deterrent. It is too dangerous a thing to surrender.

* Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange.