I will add a couple of things to Vheissu's take on this, which I consider the definitive GR review and recommend, most of all because it examines Grayling in light of institutional (air force) perspectives. (http://www.goodreads.com/review/show/124302773)
Grayling's is an important and readable account, but it really bothers me that he does not address the most egregious outcomes of this legacy to date: the Korean and Vietnam wars.
Grayling periodically refers to the criteria for jus in bello: the means employed must be necessary and proportional. He argues clearly and forcefully that area (terror) bombing in World War II was neither.
"It can certainly be granted that the overwhelming aim was to defeat the Axis powers, and it is surely right that it would have been an act of immorality not to strive fully and effectively to achieve that goal. But it is wrong to use this to justify indiscriminate bombing of towns and cities, for the familiar reason that the ends do not automatically justify the means." (p. 264)
But Grayling notes: "In practice victory tends to provide absolution for all wrongs, since the victor is judge and jury in his own behalf -- history is written by victors. In the same way, the victor nations of the Second World War have allowed their victory to excuse them from self-examination over some aspects of their behavior. But that is a wrong in itself." (p. 264)
A wrong that led blindly and directly to America's bombing wars in Korea and Vietnam.
In the Korean War, the air force gave up trying to distinguish between enemy and friendly civilians. Distinctions in general are damn hard to make in a bombing war, but in Korea the directive about civilians quickly degenerated into "bomb anybody wearing white."
In case you missed it (and it was easy to miss, because as far as I can tell it was hardly mentioned), I'll offer the example of Gokgyegul. In 2008, Jae-Soon Chang reported for the Associated Press that:
"After a two-year investigation, the story of Gokgyegul, the Cave of the Crying Stream, was confirmed on May 20 (2008) by the South Korean government’s Truth and Reconciliation Commission. It was one of the first inquiries completed among dozens of such cases of alleged mass killing of South Korean civilians by American forces in 1950-51. 'The U.S. military hardly took into consideration a risk that its massive bombing and incineration operations could take heavy tolls on civilians,' the commission concluded, calling the attack indiscriminate and saying the U.S. had failed, with the roadblock, to meet its responsibility to safeguard refugees.
"Declassified U.S. military records show that the Americans, on guard against possible enemy disguised as refugees, were blocking South Korean civilians fleeing the fighting. Air Force pilots were told to view 'people in white' – the color most civilians wore – as potential enemy.
"Yeongchun (South Korean) villagers left their homes and moved into the nearby 85-yard-long cave, named for the crying sound of its intermittent stream. Outside they tethered cows and stacked household goods.
'People thought they’d be safe inside,' said Cho Tae-won. But on Jan. 20 at 9:50 a.m. two or three Air Force F-51 Mustangs struck, the U.S. record shows.
"'They dropped oil drums (gasoline-gel napalm bombs) and then the fire incinerated everything and spread into the cave,' Cho Byung-woo, 66, told Associated Press reporters visiting the site . . . . The truth commission concluded that well over 200 [South Korean] civilians were killed." (AP, Jae-Soon Chang, 2008)
And that was just at Gokgyegul. Granted, the above was released after Grayling's book, but his research easily could have turned up information about the investigation, and plenty of information about the Korean air war was available to him.
Combat pilots continued to attempt to distinguish themselves by their given planes and expertise (in props or jets, singles or heavies, as fighters or bombers or fighter-bombers), most experiencing not the slightest sense of irony over the generic tons of incorrigibly and massively explosive ordnance to which the air force had at some point reduced almost all of them.
So armed, the air force proceeded to Vietnam, about which I wish Grayling had talked to Earl H. Tilford Jr. Tilford is a historian and former air force intelligence officer who served in that war. In Crosswinds: The Air Force's Set Up In Vietnam, Tilford writes:
"More than half of the hundreds of billions of dollars spent on the Vietnam War went to support Air Force, Army and Navy aerial operations. The Air Force built up its forces the fastest of any service, reaching near peak strength by mid-1966, and remained in Southeast Asia longer than any other service, not closing down its Thailand-based headquarters until January 1976.
"The United States dropped eight million tons of bombs on Vietnam, Laos and Cambodia between 1962 and 1973 – the Air Force accounted for nearly 80 percent of those bombs. Total U.S. aircraft losses, fixed wing and helicopter, came to 8,588. The Air Force lost 2,257 aircraft and more than 2,700 Air Force men died while hundreds of airmen endured torture in captivity. For all that expenditure of treasure, firepower, and lives, air power, while occasionally pivotal, was never decisive in the Vietnam War.
"The failure of American air power in the Vietnam War cannot be blamed entirely on politicians 'who tied our hands,' a pernicious and 'wayward' press, or the antiwar movement. Air Force leaders, especially the air commanders in Saigon, Honolulu, and Washington between 1964 and 1972, share much of the blame. In the final analysis, they could not – indeed, did not – develop a strategy appropriate to the war at hand.
"In fact, they failed to articulate any coherent strategy at all. In Vietnam the Air Force fell victim to its own brief history and to the unswerving commitment of its leadership to the dubious doctrine of strategic bombing." (Crosswinds, Preface)
That commitment has proved to be the most enduring and damning and tragic legacy of all. Had Grayling more thoroughly examined it, I'd have granted five stars.