FORTY YEARS AGO Germany's cities lay in ruins. No one had done more to destroy them than Sir Arthur Harris, who led the Royal Air Force's Bomber Command. His many critics have censured his offensive for immorality or ineffectiveness or both.

After publishing his own account of the bomber offensive in 1947, Harris turned his back on the controversy. Not until 1971 did one of Harris' wartime subordinates, Dudley Saward, get Harris' permission to write a biography. Saward had access to Harris' correspondence and taped 50 hours of interviews. The biography was completed in 1976, but Harris forbade publication until after his death, which came in 1984 just short of his 92nd birthday.

The circumstances of its publication aroused hope that Saward's biography would offer a candid view of influential personalities. But this is a remarkably impersonal book -- so much so that Harris' first wife is not even mentioned. Harris is obscured by Saward's attempt to prove that his former boss was "groomed by destiny" to save Great Britain.

There is just enough of Harris here to whet our curiosity. During the First World War he flew against German Zeppelins bombing London. He studied bombing through the interwar years, partly in the context of providing "air control" for Iraq. After helping to break up the Ottoman Empire, the British governed Iraq under a League of Nations mandate. Harris commanded one of eight RAF squadrons which suppressed tribal unrest by dropping warning leaflets, sometimes followed by bombs.

When Germany invaded Poland in 1939, Harris was a hard-driving, middle-aged officer with a young pregnant wife, an ulcer, and a preoccupation with bombing. A year later he could be found night after night on the roof of the Air Ministry -- watching the Germans bomb London. He judged their bombing too light, too spread out over space and time, with too little attention to the best mix of incendiary, blast, and fragmentation bombs.

Soon after taking charge of Bomber Command in 1942, Harris managed to scrape together 1,000 bombers for a single raid. He had to use more than 300 training aircraft, and heavy losses might have cost him his career. Instead the unprecedented devastation of Cologne helped to win support for building a Bomber Command which could make heavy raids repeatedly. The British press and people discovered a hero whom they affectionately dubbed "Bomber" Harris.

At his home near High Wycombe, Harris entertained visitors in his "Conversation Chamber," where they could examine photographs of the punishment wreaked by his bombers. He was himself a frequent visitor at Chequers, the prime minister's country residence. Though Churchill's support for bombing ran hot and cold, Harris got much of what he wanted.

HARRIS competed with rivals outside and inside the RAF for Great Britain's limited resources. He necessarily plays an important role in John Terraine's lively history of the RAF during the Second World War -- a much larger role than Terraine thinks Harris should have played.

Terraine seems torn between his respect for the sacrifice of nearly 50,000 RAF bomber crew members and his nagging suspicion that they and more than 300,000 German civilians may have died needlessly. He is least uncomfortable with the bombers before D-Day, when they were much less potent. He suggests that bombing was the only way to attack Germany itself until an invasion force could be gathered. The strength of German air defenses forced the RAF to bomb at night, when hitting a target smaller than a city was exceedingly difficult.

In 1944 American bombers penetrated Germany in daylight with endurable losses -- thanks to long-range fighter escort. After British and American troops moved into France, navigation radio transmitters were installed nearer Germany, so that bombing accuracy could improve in bad weather and at night. Yet Harris continued to ignore demands to focus on oil and other "panacea" targets (as he called them) at the expense of city bombing. Not even Sir Charles Portal, chief of the air staff, could persuade (let alone order) him to cooperate fully.

Terraine's version of this story makes a fragile distinction between precision bombing of oil targets and area bombing of cities. Many American attacks on oil and transportation targets could be called area bombing. Since oil targets were often in the countryside, in villages, or in city outskirts, even area bombing usually caused fewer civilian casualties than bombs falling on a city center. Nevertheless, American bombing of target systems and British bombing of cities could look much alike.

The very deadly bombing of Dresden in February 1945 was not simply part of Harris' city-busting campaign, as Terraine implies. He neglects to say that Churchill called for bombing cities in eastern Germany, apparently as a way of interfering with the movement of German troops to meet the Soviet advance.

Terraine's uncertain handling of the bomber offensive contrasts with the confident judgments which populate the rest of his book. He defends Sir Hugh Dowding's conduct of the Battle of Britain; applauds the role of Coastal Command in the Battle of the Atlantic; praises Lord Tedder's ability to work with the British and American armies. But none of Terraine's characters seizes his imagination as does Harris. There is something curiously moving about Terraine's reluctant tribute to Harris' ruthless perseverance and "warm and magnanimous heart."