War's clouded morality

History: On the night of December 29th, 1940 the British chief of the air staff, Sir Charles Portal, went up on the roof of …

History: On the night of December 29th, 1940 the British chief of the air staff, Sir Charles Portal, went up on the roof of the air ministry with his deputy, Sir Arthur Harris, to watch London burning under Luftwaffe attack. They looked on in silence at the destruction, with the dome of St Paul's Cathedral "standing out in the midst of an ocean of fire".

Eventually the junior man turned and said, "Well, they are sowing the wind". The following winter Portal asked Harris to run Bomber Command, giving him the chance to unleash that storm. His campaign of mass destruction against German cities helped win the war, but at a cost of more than half a million civilian lives. AC Grayling says that makes "Bomber" Harris a war criminal.

Harris revitalised Bomber Command when he took over in February 1942. He had served in the Royal Flying Corps during the first World War and had seen at first hand the barbarity of the western front. This provoked in him an ardent belief that the pain and expense of a ground war could be avoided by the right application of air power. Within months of arriving at Bomber Command he launched his first spectacular "1000-bomber" raids. On May 30th, 915 tons of incendiaries and 840 tons of high explosives hit Cologne. More than 600 acres of the city were flattened. About 13,000 buildings were destroyed, making more than 45,000 people homeless and killing 469. More damage was done to the city in one night than in all previous air raids during the war. This was the beginning of a sustained attack on Germany's principal cities, including Hamburg, Dresden, Leipzig, Nuremberg and Berlin.

The experience for those on the receiving end was appalling. Cities became like "the pan of a gigantic oven". Survivors spoke of "the tremendous force of hot, dry winds ... bundles of flame ... a blizzard of red snowflakes ... and the shrieking, howling of the storm as it raced through the streets". The psychological impact was often worse. One refugee from Hamburg recalled a woman at a train station dropping her suitcase, which "bursts open and spills its contents. Toys, a manicure case, singed underwear. And last of all, the roasted corpse of a child, shrunken like a mummy, which its half-deranged mother has been carrying about with her, the relic of a past that was still intact a few days ago."

Such details have made it easy to suggest that the man who planned such a campaign must be a monster. Harris often did not help his own case. He would repeat with gusto the story of being stopped for speeding on a journey back from London to Bomber Command headquarters in Buckinghamshire. "Sir, you're travelling much too fast, you might kill someone," scolded the policeman. "It's my business to kill people," Harris replied: "Germans."

This absorbing book by AC Grayling on area-bombing is not primarily a historical one. He freely admits that he has not trawled the archives looking for new information or read much beyond the English language secondary literature on the subject. Rather Among the Dead Cities is a timely philosophical reflection on the ethical complexity of war. What impress most are the depth of Grayling's own humanity and the intellectual vitality of his argument. He is moved to incandescence by area-bombing, but refuses to offer glib answers. He builds his case patiently, giving readers the opportunity to disagree, and openly acknowledges weaknesses in his logic. Harris, so often portrayed as a pantomime villain, emerges as a many-sided individual, not least in the chapter entitled "The Mind of the Bomber". In the end, however, Grayling offers an unequivocal judgement on the British and American air forces that bombed both Germany and Japan. "The area-bombing campaigns of the second World War were as a whole morally criminal," he concludes. "It cannot be said that deliberately targeting civilians and dropping thousands of tons of bombs on them remorselessly over many years is a side-effect of war."

Most military historians will disagree. Firstly, Harris's area-bombing made a highly effective contribution to the war. The 1000-bomber raid enhanced British morale, not least in cities that had suffered so much during the Blitz. The raids were politically significant in pacifying Stalin, who complained that not enough was being done to relieve Soviet forces. Attacks on industrial targets reduced German tank and aircraft production by more than a third. And crucially, in 1944, by obliging Hitler to defend the German homeland against air attack, area-bombing gave Anglo-American forces a decisive advantage on D-Day and beyond.

Part of the difficulty, as Grayling concedes, is that war is a dirty business in which nation states usually do whatever is necessary to ensure their survival. Collective agreement on the ethics and practice of war is difficult to achieve. In the years leading up to the second World War, interminable disarmament talks attempted without success to limit the means for making war. "The course we are now following is straight towards the destruction of our civilization," Stanley Baldwin, the British delegate at the Geneva Disarmament Conference, warned his US counterpart in 1932, "and something radical has to be done unless we are all going down together." His proposal was the total abolition of all military aviation. Soon afterwards, dejected by the failure to reach agreement, he coined a bleak prophetic axiom for the future of warfare: "The bomber will always get through."

He did, and as Grayling dejectedly concludes, any observer of that conflict would have to suppose that in "the situation regarding humanitarian restraint in war . . . scarcely any progress had been made since a sagacious Roman 2,000 years beforehand commented that inter arma silent leges: in time of war the laws are silent."

Richard Aldous teaches modern history at UCD. His next book, The Lion and the Unicorn: Gladstone vs. Disraeli, will be published by Hutchinson in autumn

Among the Dead Cities By AC Grayling Bloomsbury, 361 pp. £20