Volume Five: T HE PACIFIC: MATTERHORN TO NAGASAKI JUNE 1944 TO AUGUST 1945

Office of Air Force History, Washington, D.C., 1983

China/Burma vs. island strategy

“The decision to mount the invasion of Japan from island bases without benefit of a lodgment on the east China coast meant that the war would end, as it had been waged throughout, with no real connection between the Pacific theaters and China-Burma-India. In the latter theater problems of strategy and command had been even more difficult of solution than in the Pacific, being rooted in the divergent interests of the three Allied nations and made bitter by the personal animosities of some leaders. China-Burma-India, lying at the extreme end of the supply line from America, was accorded a very low priority, and geographical factors within the theater made it difficult to use the bulk of the resources in combat: most of the tonnage available was spent merely in getting munitions to the various fronts. There were few U.S. ground forces in CBI, most of the troops being air or service forces whose mission was to see that a line of communication was preserved whereby China could be kept in the war. The Tenth Air Force, having earlier protected the southern end.

B-29 target cities in Japan

Leyte

Ormac Bay

Palau Islands map

Japanese Sho- plans

“Since Allied positions in the Marianas now permitted an attack on the Japanese mainland, the Japanese planners drew up a series of defensive plans for all-out fleet employment. SHO I provided defense of the Philippines; SHO I1 for Formosa, Nansei Shoto, and south Kyushu; SHO I11 for Kyushu-Shikoku-Honshu; and SHO IV for Hokkaido. Most of the surface strength had been dispatched to Lingga in the NEI where it was adjacent to fuel, but by 17 October the Japanese carriers, which had moved back to Empire waters to train new pilots after their Marianas losses, were still not completely outfitted. Thus the final plan for implementing SHO I, devised by Admiral Toyoda, had to rely on brilliant improvisation. For cover, Japanese surface units would depend upon shore-based planes in the Philippines; the carriers would move south from home waters principally as a diversion. If these carriers could lure Third Fleet vessels northward and away from Leyte, the Japanese hoped that their heavily armed surface ships (the Yamato and Musashi each mounted nine 18.1-inch guns, the most powerful main batteries in the world) would be able to break through the remaining Allied forces and destroy the beachhead as reinforced ground troops pressed the invasion forces back to the sea.”

Leyte

“The tenacity with which the Japanese fought for control of the skies over Leyte cost them dearly, while, at the same time, Allied fighter losses were low. In all, the Japanese sent more than I ,03 3 sorties over Leyte between 27 October and 3 I December; of this number, V Fighter Command pilots shot down 314 and probably destroyed 45, losing only 16 of their own planes in aerial combat. By 25 December Marine fighter pilots had destroyed forty-two enemy aircraft and probably destroyed two, at a cost of seven F4U’s. Sixth Army AA units claimed 250 definites and I 10 probables between 2 0 October and 2 5 December.”

Luzon and Japanese suicide boats

“Nor was the Japanese Navy in condition to attempt more than hit-and- run strikes against a Luzon invasion. The Allies expected strong interference from submarines and from hayabusa boats, the latest agency of suicide attack perfected by the desperate Japanese. These high-speed torpedo boats, armed with a warhead of depth charges, were designed for crash attacks on Allied vessels. Shelters for them had been noted in Subic and Manila bays and along the southeast coast of Batangas; one P/W from a Batangas squadron had identified nine such squadrons on Luzon and claimed that his own unit possessed thirty such boats.”

Lingayen Gulf

Luzon

Corregidor

Bombing Japan

“Tokyo was a natural choice for XXI Bomber Command’s first strategic mission: except for the Doolittle raid in April 1942 the capital city had experienced no air attack, and a successful strike would have important psychological effects within Japan and among the Allied nations. But the choice was also justified by material considerations based on intensive study of Japanese industry. In earlier chapters it has been shown that the MATTERHORN plan for strategic bombardment by XX Bomber Command’s B-29’s staging through fields at Chengtu was guided by a report of the Committee of Operations Analysts issued on I I November 1943. Deliberately restricted to economic objectives, this report had listed six profitable target systems: merchant shipping, steel production, antifriction bearings industry, urban industrial areas, aircraft plants, and the electronics industry. Although no internal priorities were given, by strong implication the steel industry was preferred above the others, and since that industry alone offered important targets within range of Chengtu, XX Bomber Command had during the early months of its campaign gone out against steel plants in Kyushu and Manchuria.”

“Under the first assumption, the air-sea war, the COA recommended attacks against Japanese shipping (to include a comprehensive VLR mining campaign), the aircraft industry, and Japanese urban industrial areas. Mining was to be a continuing program, but after completion of planned attacks against aircraft factories and urban areas, the strategic target program was to be reviewed in search of more profitable objectives-the food supply, for instance, might be vulnerable to air attack. Recommendations under the second assumption were similar, though the order of items and the emphasis were changed: an attack on the aircraft industry and on urban industrial areas and an intensification of the attack on shipping by all available means, including mining by VLR aircraft where operationally feasible.” Although first priority was given to the aircraft industry, the COA believed that, if possible, mining operations should be conducted concurrently. For the area attacks, six cities were named-Tokyo, Yokohama, Kawasaki, Nagoya, Kobe, and Osaka-but the .attacks were to be delivered only when they could be done in force and within a short time. Because the JCS believed that an invasion of Japan would be necessary, it was the latter set of recommendations which was to guide the Twentieth Air Force in its choice of targets; the lessons of the Combined Bomber Offensive in Europe had had a sobering effect, and no person of authority in the AAF urged the probability of a victory by air power alone. There was no disagreement with the COA opinion that shipping losses had so threatened Japan’s industrial balance that it would be profitable to neglect such long-term objectives as steel in order to cripple those industries geared directly to the military machine.”

Iwo Jima

“Japanese raids against B-29 bases, though troublesome, were not important enough alone to have justified the cost of capturing Iwo Jima: the decision to seize the island was made a month before the raids began and they had ceased seven weeks before Iwo was assaulted. Meanwhile, the island had proved a hindrance to the VHB campaign in other ways. Since fighters based on the rock had attacked B-29’s en route to or from Japan, to avoid interception the bombers had been forced to fly a dogleg course which complicated navigation and reduced bomb loads; even then, enemy radar at Iwo gave early warning to Honshu of northbound Superforts. But the idea of seizing the island derived less from its menace while in Japanese hands than from its potential value as an advanced base for the Twentieth Air Force.”

“The cost in human lives was heavy. US. losses, excluding Navy personnel, were estimated by USSBS at 4,590 killed, 301 missing, and I 5,954 wounded, a total of 20,845. In return, the Americans killed an estimated 2 I ,304 Japanese and captured 2 I 2.83 In a war of attrition this would have been an acceptable exchange, but the battle of Iwo Jima was for a small piece of valuable real estate, not primarily to inflict casualties upon the enemy.”

“ By the end of the war about 2,400 Superforts had made emergency landings on its runways. Perhaps the estimate cited by Admiral King that the lives saved “exceeded lives lost in the capture of the island itself” is the most accurate and just one.”

Incendiary Bombing of Japanese cities

“There was a popular belief in the United States that Japanese cities would be highly susceptible to incendiary attacks. When serious study of strategic air targets in Japan began in March 1943, there were many who agreed with this view. Tests conducted at Eglin Field and Dugway Proving Ground on model urban areas of typical Japanese construction seemed to add scientific confirmation to a judgment based on common sense. An air intelligence study completed on 15 October I 943 concluded that Japanese cities would prove much more vulnerable to fire bombing than had comparable German cities, because of more inflammable residential construction and greater congestion. Japanese military and industrial objectives were frequently surrounded by crowded residential sections and were hence exposed to sweeping conflagrations-indeed, much of the manufacturing process was carried on in homes and small “shadow” factories. Japanese industry, unlike German, was concentrated in a few cities, and it was estimated that the industrial areas of the twenty leading cities could be burned out with about 1,700 tons of M69 bombs-a 6-pound oil incendiary that was highly effective against light construction.‘ This calculation referred to bombs actually on target, not to the total weight dropped, but even so AC/AS, OC&R, considered this weight much too light.’ Since subsequent efforts to revise the estimate produced no generally acceptable figure and since both operational and logistical agencies needed a realistic planning factor, it was especially important that test fire-bombing raids be run in the theater.”

The Great Fire Raids

“The decision to attack at night ruled out the command’s standard technique of lead-crew bombing. Formation flying at night was not feasible, and with flak rather than enemy fighters the chief danger, a tight formation would be a handicap rather than a source of defensive strength. With planes bombing individually from low altitudes, bomb loads could be sharply increased, to an average of about six tons per plane. Lead squadron B-29’s carried 180 x 70-pound M47’s, napalm-filled bombs calculated to start “appliance fires,” that is, fires requiring attention of motorized fire-fighting equipment. Other planes, bombing on these pathfinders, were loaded with 24 x 500-pound clusters of M69’s. Intervalometers were set at roo feet for the pathfinders, 50 feet for the other planes. The latter setting was supposed to give a minimum density of 25 tons (8,333 M6g’s) per square mi1e. Since the first Empire strike, no mission had attracted such interest or anxiety. Planning had been shrouded in more than customary secrecy. Norstad, who had come out for a conference on the Okinawa operation, arrived at LeMay’s headquarters on 8 March and, when he had been briefed, alerted Lt. Col. Hartzell Spence, the Twentieth‘s public relations officer in Washington, for “what may be an outstanding show.”“ It was to be outstanding in size: 334 B-29’s would take off with about 2,000 tons of bombs. More important, it was to be a most effective strike.”

“Planes from the 3 14th Wing’s 19th and 29th Groups took off from North Field on Guam at 1735 on the 9th. Forty minutes later the first planes of the 7 3d and 3 I 3th Wings left for the somewhat shorter trip from Saipan and Tinian. It took two and three-quarters hours to get the whole force airborne.” On the way out the B-29’s encountered turbulence and heavy cloud, but navigators easily identified landfall, coast IP, and the target area. Weather over target was better than usual, with cloud cover varying from I /IO to 3/10 and initial visibility of ten miles. The first pathfinders readily located their aiming points and a few minutes after midnight marked them with fires that started briskly from the M47 bombs. The three wings came in low, at altitudes varying from 4,900 to 9,200 feet, and as initial fires spread rapidly before a stiffening wind, the B-29’s fanned out, as briefed, to touch off neb fires which merged to form great conflagrations. The area attacked was a rectangle measuring approximately four by three miles. It was densely populated, with an average of 103,000 inhabitants to the square mile (one ward, the Asakusa, averaged 135,000) and a “built-upness,” or ratio of roof space to total area, of 40 to 50 per cent, as compared to a normal American residential average of about 10 per cent. The zone bordered the most important industrial section of Tokyo and included a few individually designated strategic targets. Its main importance lay in its home industries and feeder plants; being closely spaced and predominantly of wood-bamboo-plaster construction, these buildings easily kindled and the flames spread with the rapidity of a brush fire in a drought, damaging the fire-resistive factories."

"The bombs-away message set the pattern for future reports: “Bombing the target visually. Large fires observed. Flak moderate. Fighter opposition nil.” Late formations reported general conflagrations that sent them ranging widely in search of targets, with visibility greatly reduced by smoke and with bomb runs made difficult by turbulence created by intense heat waves. Tail gunners on the trip home could see the glow for 150 miles.’ Opposition had been only moderately effective. The Japanese later admitted that they had been caught off base by the change in tactics, being prepared for neither the low-altitude approach nor the heavy attack. The several B-29 formations reported flak of varying degrees of intensity and accuracy; automatic-weapons fire was generally too low and heavy AA too high, and the volume fell off sharply as fire or heat overran gun positions. Fighter defense, originally reported as nil,” was weak throughout the three-hour raid. B-29 crewmen reported only seventy-six sightings and forty attacks by enemy planes, usually while the Superforts were caught in searchlight beams. Crewmen thought the interceptors worked without benefit of radar, being guided in solely by the searchlights, an assumption verified by postwar investigation. The fighters did not score, but flak damaged fortytwo B-29’s and was responsible for the loss of fourteen, including five whose crews were picked up at sea by air-sea rescue units. The loss ratio in terms of sorties was 4.2 per cent as compared with a figure of 3.5 per cent for all B-29 missions and of 5.7 for January. In these moderate losses, as in damage inflicted on the enemy, LeMay’s tactics had been justified?’ So fierce was the fire that it had almost burned itself out by midmorning, checked only by wide breaks like the river. Photographs taken on I o and I I March indicated that an area of I 5.8 square miles had been burned out. This included 18 per cent of the industrial area, 63 per cent of the commercial area, and the heart of the congested residential district. The XXI Bomber Command’s intelligence officers struck off their lists twenty-two numbered industrial targets”

Results of the raids

Attack on Osaka

“The high concentration of bombs over so wide an area started so many fires that, according to the fire chief, the situation was out of control within thirty minutes. The flames caught and destroyed 95 fire engines, killed 125 firemen. Buildings of light construction were consumed utterly with their contents. There was little rubble left; only an occasional fire-resistant building, scarred by the heat, remained in the razed areas. Police records show that 267, I 7 I buildings were destroyed-about one-fourth of the total in Tokyo and that I ,008,005 persons were rendered homeless. The official toll of casualties listed 83,793 dead and 40,918 wounded. It was twenty-five days before all the dead had been removed from the ruins. Panic had been partly responsible for the heavy casualties, since persons trapped by spreading fires had tried to dash through the flames. Many found safety in the firebreaks, rivers, and canals, but in some of the smaller canals the water was actually boiling from the intense heat.” Radio Tokyo labeled the raid as “slaughter bombing.” One broadcast reported that “the sea of flames which enclosed the residential and commercial sections of Tokyo was reminiscent of the holocaust of Rome, caused by the Emperor Nero.’’ It was good propaganda to picture LeMay as a modern Nero (though he smoked a cigar instead of fiddling while sweating out the mission), and there are passages in Tacitus’ famous account of the disaster of 64 A.D. that might have been applied to that of 10 March. But the physical destruction and loss of life at Tokyo exceeded that at Rome (where ten out of fourteen wards of a much smaller city were consumed) or that of any of the great conflagrations of the western worId-London, 1666 (436 acres, I 3,200 buildings) ; Moscow, 1812 (38,000 buildings) ; Chicago, 1871 ( 21 24 acres, 17,450 buildings); San Francisco, 1906 (4 square miles, 21,188 buildings).” Only Japan itself, with the earthquake and fire of 1923 at Tokyo and Yokohama, had suffered so terrible a disaster. No other air attack of the war, either in Japan or Europe, was so destructive of life and property. The effect on Japanese morale was profound.” An official of the Home Affairs Ministry later reported:”

“People were unable to escape. They were found later piled upon the bridges, roads, and in the canals, 80,000 dead and twice that many injured. We were instructed to report on actual conditions. Most of us were unable to do this because of horrifying conditions beyond imagination.”

“While Tokyo searched for its dead, the attack turned against other cities.”

“On the afternoon of 11 March, less than twenty-nine hours after the last plane had returned from Tokyo, a force of 3 I 3 B-29's began taking off for Nagoya, Japan's third largest city and hub of her aircraft industry. The XXI Bomber Command had visited Nagoya in six precision attacks and one test incendiary raid without significant results; this time the command would try to burn out the vital central and industrial core of the city in tactics similar to those used at Tokyo.”

“The pathfinder planes again were loaded with M47 incendiaries. Had the supply been sufficient, these bombs would have been used exclusively, but there were not enough at hand; field orders called for the use of any incendiaries available in M69 clusters. Each plane carried 2oo rounds of .5o-caliber ammunition for the tail guns. The B-29's had done well enough without ammunition over Tokyo, but eventually the enemy would discover that the planes were unarmed; moreover, some group commanders thought the tail gunners might knock out a few searchlight. The planes got off between 1710 and 1951. One ditched soon after take-off and nineteen others aborted. The 285 that reached Nagoya went in at altitudes from 5,100 to 8,500 feet and unloaded I ,790 tons, I 25 more than had been dumped on Tokyo. The target area was a triangular wedge of the city with a built-up ratio approaching 40 per cent and a population of about 70,ooo to the square mile. The aiming points were spaced to avoid blacking out the target for late arrivals and the target run was up wind. The 3 14th Wing was on target but the 3 I 3th and 73d dropped short. Many fires were started-394 separate fire areas were later identified -and some of these spread until stopped by firebreaks. Next morning a submarine 150 miles offshore reported its visibility cut to one mile by woodsmoke.”

“But there was no such general holocaust as had gutted Tokyo. Post-strike photos showed only 2.05 square miles destroyed, and this total was made up of many burnt spots scattered through the city. Eighteen numbered industrial targets (i.e., plants given a special designation in the target folders) were damaged or destroyed, but the aircraft plants were not wiped out. Most seriously hurt of this type of factory was Aichi's Eitoku plant, but the decline in production thereafter was negligible-from I 10 planes in February to 106 in March,"

“That success was less spectacular than at Tokyo was due in part to circumstances over which XXI Bomber Command had no control. There was little wind to fan the fires started. Nagoya had an adequate water supply, well-spaced firebreaks, and an efficient fire department which adopted excellent tactics for the 0ccasion.4~B ut there were also errors in planning that had resulted from misinterpretation of the huge success at Tokyo. For the Tokyo raid, intervalometers on all B-29’s except the pathfinders had been set to loose incendiary clusters at intervals of fifty feet. The stories of returning crews regarding the rapid spread of the fires created the false impression that bombs had been wasted by dropping them too close together. For Nagoya the setting was for intervals of IOO feet, which gave a density pattern too thin for the purpose desired. The method of attack, copied from Tokyo, also proved inefficient. The Superforts went over in two waves with bombardiers briefed to place their bombs visually in the vicinity of the aiming points so as to cover the entire area. Only a few planes made a controlled run over the target, and the attempt to scatter the bombs by snap judgment resulted in too wide a dispersal.

The document then goes on to give some rather interesting statistics. It compares the planned target area to be bombed with the area actually destroyed, all in square miles. Tokyo had 55 square miles targeted, and 56.3 square miles were destroyed. Nagoya had 16 sq. miles targeted, and 12.4 square miles were destroyed.

Kobe had 7 square miles targeted, and 8.8 square miles were destroyed. Osaka had 20 square miles of target area, with 15.6 square miles destroyed. Yokohama had 8 square miles targeted, and 8.9 square miles destroyed. Kawasaki had 6.7 square miles targeted, and 3.6 square miles were destroyed.

“The six most important industrial cities in Japan had been ruined. Great factories had been destroyed or damaged; thousands of household and feeder industrial units had gone up in smoke. Casualty lists ran into six figures. Millions of persons had lost their homes, and the evacuation of survivors had made it difficult to secure labor for those factories that remained.”

The air-raid protection system in Japan was pitifully inadequate to

“The probable effect of the raids on Japanese morale were accurately diagnosed by Joseph C. Grew, Ambassador to Japan until Pearl Harbor and Acting Secretary of State in the spring of 1945. Immediately after the Tokyo attacks of 23 and 25 May, he attempted to persuade Truman to temper his “unconditional surrender” message of 8 May with a statement that the United States had no intention of abolishing the emperor’s office. Grew thought that with such a guarantee the Japanese, to avoid further losses at home, might be willing to capitulate. According to Grew’s account, Truman was sympathetic to the proposal but was dissuaded by his military advisers, who feared that such a concession during the tough going on Okinawa might be interpreted by the Japanese as a confession of weakness. Grew has since reaffirmed his belief that the war might have been ended earlier by this procedure. Certainly there was a sharp slump in civilian morale in the wake of the fire blitz, as postwar opinion surveys clearly demonstrate,and a renewed effort on the part of some officials to negotiate for peace.”

lncendiary Attacks on the Smaller Cities

“The incendiary campaign begun by XXI Bomber Command in mid-May was based on a Joint Target Group study of 28 March, which listed thirty-three urban areas concentrated in eight of Japan’s largest cities.* One, Yawata, was not hit; as the others were reduced to cinders in successive raids, it became increasingly obvious that the same tactics should be applied to the smaller cities: the efficiency and light cost of the night raids and the weather outlook were convincing arguments. LeMay’s A-2, Col. James D. Garcia, stressing the importance of cumulative effects of raids compressed within a short period of time, recommended a systematic attack on medium-sized cities now that there was “a possibility of achieving a decisive effect with air power.” His choice of preferred targets was based on the following factors: I) congestion and inflammability; 2) incidence of war industry; 3) incidence of transportation facilities; 4) size and population; and 5) adaptability to radar bombing. The list of 25 cities, with populations ranging from 323,200 (Fukuoka) to 62,280 (Hachioji) was merely a tentative one but it served well enough to get the campaign under way: of the first 15 targets struck, 1 3 were from Garcia’s selection and eventually all but 5 were hit. His estimate of forces required - an educated guess” in advance of photo reconnaissance-was about double what was actually used, and as the original targets were quickly scratched, others were added until by 14 August fifty-eight towns had been fire-bombed.”

Nagasaki post-strike photo

Hiroshima before attack

Hiroshima after attack

Nagasaki

Effect on Japanese Morale

“In a scientifically designed study of public opinion, USSBS found great uniformity in psychological reactions among various classes of society, whether urban or rural. The easy conquests of the early months of the war brought high confidence in eventual victory and since the government suppressed or warped all news of subsequent defeats, this optimism continued well into 1944: as late as June of that year apparently only 2 per cent of the people believed it probable that Japan would lose the war. After the fall of Saipan it became impossible to hide the major losses and in an endeavor to strengthen the war effort the government changed the nature of its propaganda. Reductions in the food ration and B-29 attacks, particularly those against urban areas, intensified the doubts caused by military failures and all morale indexes show a steady decline. The percentage of people believing Japan would lose the war rose to 10 in December 1944, 19 in March 19$5,46 in June, and 68 just before the surrender. Over half of those believing in eventual defeat “attributed the principal cause to air attacks, other than the atomic bombing attacks.” By the end of the war 64 per cent of the populace had reached a point where they felt “personally unable to go on with the war.” Here again the most important cause of defeatism was the air attacks, which for a majority of the respondents outweighed the other reasons most frequently given-military defeats and food shortages. This attitude toward air attacks pervaded the whole of Japan as evacuees from bombed cities infected other communities with their pessimism and as Allied planes flew over all parts of the home islands with hardly a challenge from the defenders. Lowered morale was reflected in a loss of faith in civil and military leadership and in the armed forces, in distrust of government propaganda, and in an increase of complaints and criticism."

"The tradition of passive obedience and the effectiveness of the police system prevented any open break, and it seems probable that the people would have continued to support the war so long as the Emperor commanded. Nevertheless, the deterioration of morale was an important factor in Japan’s defeat: it contributed to the decline in production and it influenced those leaders who finally engineered the surrender and who, incidentally, had arrived at a state of hopelessness earlier but from reasons not unlike those of the masses. The atomic bomb attacks contributed to a sense of defeatism in Hiroshima and Nagasaki, where morale had been better than average, but had a “more restricted” effect on civilian attitudes e1sewhere. The nature of the bomb was better understood by the military and the threat of additional attacks helped shape the surrender, but the chief importance of the bomb, as of Russia’s declaration of war, was in providing an excuse to recalcitrant militarists. Even without those face-saving blows, in the opinion of the survey, “air supremacy over Japan could have exerted sufficient pressure to bring about unconditional surrender and obviate the need for invasion”-probably by I November, certainly by the end of December 1945. The vast expansion of air operations contemplated the B-29’s were expected to reach a monthly rate of I I 5,-ooo tons of bombs during that period, as opposed to 42,700 tons in July."



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