Before Hiroshima: The Bombing of Japan 1944-45

On 5th July, 1928 the citizens of Osaka, Japan's second largest city, experienced blacked-out streets and air raid sirens for the first time. Long before Pearl Harbor Japanese leaders recognised bombing as a danger, and began air raid drills in major cities. At first these were amateurish rehearsals; but as war approached new laws and organisations laid the foundations of nationwide civil defence. In April 1937 the Air Defence Law was passed, and two years later the Greater Japan Air Defence Association began a programme of training and propaganda.

Despite these early beginnings Japan's military leaders paid surprisingly little attention to American air power. On the eve of war Prime Minister Tojo believed that overseas conquests would protect Japan from heavy bombing, and declared 'Preparations for homeland air defence must not interfere with the operations of our armed forces overseas'. Japan's conquests in South East Asia confirmed this misplaced confidence, and her air defences lagged far behind those of Britain and Germany. But in these years of Japanese complacency America was preparing the B-29, a fast, well-armed bomber able to raid Japan from distant bases. In September 1942 its test flights began at Seattle, and in June 1944 a force of B-29s arrived in China to launch attacks on the Japanese mainland.

News of the B-29 and the devastation of German cities gradually destroyed the assumptions of Japanese strategists. On April 18th, 1942 sixteen carrier-borne B-25s had made a symbolic raid on Tokyo, Nagoya and Kobe, but by 1943 it was clear that Japan would soon face more destructive attacks. Now civil and military defence became matters of unprecedented importance.

In many respects Japan had important advantages in civil defence preparations. Her population was homogenous, united and disciplined, and in 1940 the government had converted voluntary neighbourhood associations into compulsory organisations under Home Ministry control. These groups provided a ready basis for co-operation in wartime emergencies. The Japanese family was yet another element of strength in civil defence planning. Most city dwellers retained close links with relatives in the country so that evacuation posed less difficulties than in many European countries.

In December 1943 the Japanese government presented its first proposals for evacuation. Ministers recommended that children and those without war work should leave greater Tokyo, Nagoya, Kobe, Osaka and North Kyushu. Evacuees were expected to live with relatives in the country but the government gave little help in implementing its programme. In fact evacuation gained little momentum until June 1944 when B-29s made their first raid on Northern Kyushu. At this time Ministers again called for the evacuation of children to the homes of relatives, and special provision was made for those with no grandparents in the country. Under this new plan third to sixth year junior school pupils were to be evacuated in groups. Teachers would supervise them, and they would live together in temples, inns and public halls. Few parents were happy at the prospect of divided families but official persuasion and propaganda overcame much of their resistance. By September 1944 over 411,000 children had been evacuated with their teachers, but outside the four great conurbations little organised dispersal had taken place.

As fear of bombing intensified, the Japanese government made plans to protect their cramped wooden cities from fiery destruction. The repetition of simple 'bucket relay' fire drills formed one element of official policy; but urban surgery was the most dramatic sphere of government action. In November 1943 municipalities began destroying buildings to create fire breaks. Belts up to 120 feet wide were cleared of all houses, while around public buildings everything was razed to the ground. Citizens whose homes were destroyed were compensated, but no alternative accommodation was provided. Like evacuees they were expected to share the homes of friends and relatives. By the end of the war 1,800,000 people had lost their homes as a result of these air raid precautions.

Evacuation and destruction made few demands on national resources, but shelter construction required supplies of important materials. In 1943 the government urged the building of public and family shelters; but cement and steel were in short supply. A few concrete bunkers were built for important persons but plank-covered trenches had to suffice for most civilians. These unsafe, insanitary shelters remained the only refuge for most Japanese.

If Japan's civilian defence was inadequate her military protection was almost totally ineffective. From the beginning of the war Japan possessed a warning system of picket boats, radar and observation platforms, but these were never more than a faulty shield. Japan's radar could not cope with very high or low flying aircraft; it could not detect the altitude of enemy bombers, and was too crude for operators to judge the types of aircraft which crossed their screens. There was often poor communication between observers, radar and fighter stations and this created unnecessary delays in mounting counter-attacks.

Even more serious difficulties stemmed from the aircraft which constituted Japan's fighter forces. During the war attempts were made to improve their quality and organisation, but overall they were outclassed by the technical quality of the B-29. The new American bomber could cruise without difficulty at 30,000 feet whereas few Japanese fighters could attack effectively at this altitude. Japan had no properly equipped night fighters and attempts to produce a jet fighter were still incomplete at the end of the war. Japanese forces were also handicapped by a shortage of good pilots for many had been lost in overseas campaigns. Aircraft fuel was yet a further difficulty. In 1944 American submarines destroyed many tankers and imports were insufficient for a full programme of training flights. Like all Japan's military forces her fighter units were hopelessly overcommitted. In early 1945 some squadrons were transferred to the Philippines, others were needed in Okinawa while many aircraft were held in reserve for an expected invasion.

Like her radar and aircraft Japan's anti-aircraft guns were also obsolete and inadequate. After four years of war there were still insufficient guns to protect all towns and cities, and the fire of many batteries could not reach the altitude of B-29 formations. Japan's gun-laying system was also ineffective and she lacked sufficient low calibre weapons to ward off low level attacks. In comparison with the formidable barrages which defended German cities, Japanese fire was both weak and inaccurate.

In June 1944 the United States Army Air Force planned to defeat Japan by scientific precision bombing. Its commanders believed that the B-29 could destroy key targets and paralyse Japan's economy and war-making power. To carry out this policy B-29s based in China began by attacking the Yawata steel works which produced 24 per cent of Japan's rolled steel. In many respects this first raid indicated the difficulties of accurate bombing with a new, complex aircraft. Of seventy-five bombers scheduled to attack Yawata seven were unable to take off, one soon crashed, and a further four returned to base with mechanical difficulties. When the B-29s reached their target they found it fully blacked out and thirty-two planes were forced to bomb by radar. Fifteen bombed visually and six were forced to jettison their bombs due to technical difficulties. Japanese fighters and anti-aircraft batteries mounted no serious opposition, but the Yawata steel works suffered no real damage. This was to be the pattern of most raids from Chinese bases. The complex instruments of the new bomber, insufficient aircraft and hastily trained crews all contributed to ineffective bombing.

At the time of these unsuccessful raids American forces were battling for bases closer to the Japanese mainland. In June 1944 they invaded Saipan, and by August had occupied all the Mariana islands. Immediately construction units began building large bomber bases, and in October the first B-29s arrived. Tokyo and all Japan's major cities were within range of the new airfields and on November 24th 110 bombers attacked the Nakajima aircraft factory on the outskirts of Tokyo. This was a high altitude daylight raid, but it was no more successful than the night attacks which had been launched from China. As before, Japanese opposition was ineffective but thick cloud and strong winds made accurate bombing almost impossible. Later raids on aircraft factories were equally disappointing. In fact the indirect effects of bombing were more significant than physical destruction. Fearing air raids, aircraft manufacturers began to disperse their plants to remote villages. The resulting disruption seriously reduced the output of fighter aircraft.

Inconclusive attacks continued, and on January 20th, 1945 General Haywood Hansell, commander of the Mariana force, was replaced by General Curtis Le May. The new commander was a decisive and resourceful airman with wide experience of bombing in Germany and Manchuria. At first Le May continued precision raids but he also experimented with incendiary attacks on Japanese cities. Such raids had a dual purpose; to destroy small workshops which provided components for large factories, and to demonstrate America's enormous power to the Japanese people. On February 4th sixty-nine bombers attacked Kobe with incendiaries and 2.5 million square feet of the city were destroyed. Three weeks later 172 aircraft bombed Tokyo and 27,000 buildings were burnt out. After these successes Le May adopted a dramatic new tactic. By early March over 300 B-29s had been assembled in the Marianas and he decided to launch these in a concentrated night attack on Tokyo. All aircraft were stripped of armament so that large incendiary loads could be carried, and they bombed in small formations, at 7,000 feet, to confuse Japanese radar. Many thought this a hazardous enterprise but the vast scale and novelty of the raid utterly confused Tokyo's defenders. On March 9th, 279 B-29s rained 1,665 tons of incendiaries on the densely populated North East section of the city. Tightly-packed wooden buildings blazed instantly, and a high wind whipped the flames into an immense inferno. Some canals boiled and others were choked with corpses as thousands sought refuge from the swirling fire. In the midst of this disaster fire brigades and neighbourhood associations were helpless. Medical posts and hospitals were overcome by flames, and by dawn 83,700 people were dead, 40,000 injured and over a million homeless. Fifteen square miles of Tokyo were a charred wilderness.

This immense disaster transformed both public attitudes and official policies. The evacuation of schoolchildren was extended to include first and second-year pupils, much civil defence training was abandoned, and thousands of terrified civilians streamed into the countryside. In the past exhortations to leave cities had been ineffective, now fear drove people to seek safety wherever they could.

For General Le May the attack had been an overwhelming success and he quickly applied his new tactics to other cities. On March 11th 285 bombers dropped 1,700 tons of incendiaries on Nagoya. Two days later 270 B-29s attacked Osaka. On March 16th 66,000 buildings in Kobe were burnt to the ground. A second raid on Nagoya started 192 fires. Within ten days American bombers had destroyed thirty-two square miles of urban Japan. The destruction of Japan had begun in earnest, but stocks of incendiaries were exhausted.

Before new supplies of incendiaries arrived the B-29s turned to assist the invasion of Okinawa. While American landing craft massed to attack, bombers from the Marianas raided airfields in Kyushu, Okinawa's forward defence. At the height of the battle these sorties continued, and for almost a month these targets replaced Japanese cities as the main objective of the bomber fleet.

By April 13th more incendiary bombs had been received and the destruction of Tokyo and major cities was resumed. In May the first 500 bomber raid was launched, and in two nights eighteen square miles of the capital were destroyed. By this time American bombers had a further advantage. In March United States forces had taken Iwojima; from there Mustang fighters could escort B-29s to the Japanese mainland. On May 25th Mustangs accompanied bombers on a major raid on Yokohama. They destroyed twenty-six Japanese interceptors, and increasingly Japanese defences disintegrated before the combined force of American bomber and fighter power. By mid-June the task of destroying Japan's largest cities was almost complete, and day by day millions of refugees retreated into remote villages. Now carrier-borne planes bombed and strafed, special units attacked oil refineries, and bombers dropped mines in coastal waters. Next provincial centres became prime targets for the American offensive. Fifty-two cities were largely destroyed and a further six suffered substantial damage. In this final stage of bombardment B-29s often dropping warning leaflets before raids, saving thousands of lives.

By August 5th, 1945 Japan's air defences were broken. Precision bombing had failed but fire raids had been cruelly effective. Cities were charred and ruined. 200,000 civilians lay dead, half a million were injured and 8,000,000 refugees were crowded in rural villages. Japan's war was lost, but Hiroshima was still to come.

Gordon Daniels is a lecturer in the Department of Japanese Studies at Sheffield University.