Saul David, who is peerless now among our military historians, explains at the end of this superb book on the Battle of Okinawa that its title comes from a US Navy veteran’s memoir of the battle: “While on Okinawa the marines and soldiers were going through their crucible of hell brought on by rain, heat, poison, snakes, mosquitoes… the stench of human faeces and rotting human flesh filled with maggots.”

The evidence that underpins David’s account of the battle, which raged from April 1, 1945 when the Americans invaded the island to late June when the Japanese were finally driven into submission, more than supports this idea of its ghastliness.

Okinawa was the last great battle of the Second World War; it was also the most costly in the Pacific theatre in terms of lives and casualties for the Americans. The British Pacific Fleet played a small but important supporting role in the campaign, but almost all of the Allied blood spilt was American. By the end of the battle 12,500 Americans had died and another 63,500 had been wounded.

The Japanese came off far worse: 110,000 military personnel and 125,000 civilians – a third of the island’s pre-war population – were killed. Many of those, believing the propaganda of the Japanese leadership, committed suicide (killing their children first) to prevent the Americans from raping or murdering them.

Since the Japanese occupation of much of the western Pacific in 1942, the Americans had driven the enemy back towards their homeland. In early 1945 plans were being made to attack the Japanese mainland itself, but that required a nearby landfall from which to launch airborne attacks: that was why Okinawa was so strategically useful. There was also a morale issue. Although the Japanese had a rigid code of military honour that ruled out surrender, there was just a chance that the seizure of Japan’s southernmost prefecture would make the enemy, in President Truman’s words, “see reason”.

However, momentous events took place during the battle. Twelve days into it President Roosevelt died, putting into the White House a man who had been vice-president for less than 90 days and had precious little executive experience outside that. Truman was shocked to discover that he would soon be called upon to make a more momentous decision than perhaps any man in history: he was alerted to the existence of the Manhattan Project, to develop the first atom bomb, and to its imminent availability for use against the enemy. As the battle entered its sixth week, Germany surrendered. Truman’s decision, therefore, would be whether to make America’s bomb available to the Allies to use against Japan.

David cleverly weaves in the story of that decision with an account of the fighting on the island. It is in the latter that the meticulousness of his research really starts to display itself. His is more a story of the individual soldier on the ground – on both sides – than of the deliberation of general staff officers and politicians far from the action. He describes the heroic feats of men who either never came back, or came back so scarred, physically or mentally, that they were never the same again.

Some of the names are well known: William Manchester, the writer whose account of the assassination of President Kennedy remains a classic, was a sergeant whose obstinacy saw him deny himself a commission, but who fought almost to the end in Okinawa before being wounded; and war correspondent Ernie Pyle, who had followed US troops through North Africa and Europe and won an enormous audience in doing so. Welcomed to Okinawa as a hero by the soldiers fighting there, he was killed by a sniper just over a fortnight into the battle: some of the men said his death hit them harder than Roosevelt’s.

War correspondent Ernie Pyle, centre, talks with Marines on a US Navy transport while en route to Okinawa
War correspondent Ernie Pyle, centre, talks with Marines on a US Navy transport while en route to Okinawa CREDIT: AP
But most of the heroes had no public profile at all, until they received the Congressional Medal of Honour for their exploits. One such was a Seventh-day Adventist conscientious objector who trained as a medic, Desmond Doss, who on Hacksaw Ridge, under constant enemy fire, helped winch down at least 50 wounded soldiers on stretchers, saving their lives.

While some of the legendary names of American warfare swagger John Wayne-like through these pages – General Douglas MacArthur, for example, and General “Vinegar Joe” Stilwell – it is ironic that the man who was appointed to lead the land operation, Lieutenant-General Simon Bolivar Buckner Jr should be so little known. Buckner was the son of a Confederate general from the Civil War; he had been disappointed not to see action in the Great War. MacArthur disapproved of his appointment for two reasons: he had ceded overall command of the whole operation to the navy, which MacArthur regarded as an insult to the army; and he entirely lacked field experience.

This last weakness came through in the extended nature of the battle, which others thought reflected undue caution and which overexposed the navy. This was at the height of the kamikaze operations, where suicide pilots would fly their planes into the sides of ships to disable them and kill those aboard.

Buckner made a point of going out among his troops, but he also insisted on wearing a helmet with the three stars of his rank emblazoned on it, making him easily identifiable to the enemy. At the very end of the battle, going to a command post at the front to see the action, he was killed by a Japanese missile.

In his descriptions of the lives of Japanese pilots, soldiers and civilians David creates a vivid picture of a culture that seems on a different planet; a medieval idea of dishonour that led to the military leaders on the island committing ritual suicide by plunging daggers into their stomachs (the cue for a conveniently placed soldier to slice off their heads to avoid a lingering death).

It was the carnage of Okinawa that left Truman with no choice but to order the atom bomb; hundreds of thousands, possibly millions, of young Americans and Japanese would otherwise have died as Japan fought inch-by-inch on the mainland.

Even Hiroshima was not enough to bring about surrender; it took a second bomb on Nagasaki to make the high command see the US meant business.

David discusses the pros and cons of using the atom bomb, and he rightly comes down in favour of its use, given the alternative. It is an appropriately sobering end to a highly readable and informative book that often reads like a screenplay, but depicts suffering that was all too real.