The Home Islands Ablaze
Despite the changes, LeMay was still dissatisfied with the XXI Bomber Command’s performance. During his first six weeks in the Marianas, B–29s dropped more than 5,000 tons of bombs during sixteen missions, but only one raid caused much damage. From altitudes of 25,000 to 30,000 feet above targets obscured by cloud ceilings averaging 6,000 feet, LeMay’s airmen placed less than 6 percent of bombs within 1,000 feet of their targets. The damage was hardly worth the raid’s expense in resources and lives. LeMay was getting no better results than had Hansell.
Anxious to demonstrate the effectiveness of the B–29, LeMay decided to supplement precision, high-altitude, daylight bombing with low-altitude, night incendiary bombing of Japanese cities. He had good reasons for the transition. Arnold and Norstad insisted that he use incendiary bombs. They had encouraged LeMay’s fire raid on Hankow, China, in December 1944 and had pressured Hansell to use fire raids as well. LeMay admitted: “The turkey was around my neck....”
Operations in Europe had demonstrated the effectiveness of incendiary raids. In February, British and U.S. bombers devastated the German city of Dresden, causing firestorms like those in Hamburg. LeMay and other AAF leaders speculated that the fire raids would destroy the enemy’s will to resist as well as his ability to do so. LeMay also reasoned that Japan’s predominantly wood-and-paper structures were more vulnerable to fire than was the masonry construction of German cities.
Incendiary weapons were then becoming available in quantity. Chemists at Dupont and Standard Oil, with support from the National Research Defense Council, had perfected napalm and other formulas, making the new bombs more lethal than ever. The U.S. Navy, in firm control of the water routes to the southern Marianas, could deliver the large quantities of firebombs that the XXI Bomber Command would need for incendiary raids.
However, LeMay believed that greater accuracy would not necessarily cripple Japanese production. Much of the enemy’s war industry was in small factories scattered across the cities rather than in large plants. Unlike Europe, Japan had few strategic bottlenecks vulnerable to precision bombing.
Lower-altitude strikes, from about 5,000 feet, would save fuel and engines by eliminating the need for the B–29s to climb so high during the long flight from the Marianas. Coming in beneath the high-velocity jet stream, bombers would not have to f ight powerful headwinds, and bombardiers would not have to worry about tailwinds driving the bombers too quickly over the targets. The fuel savings would allow each bomber to carry more bombs, and flying below the average height of the cloud cover would make the targets more visible, even at night. LeMay preferred night raids, which would reduce the effectiveness of Japanese antiaircraft artillery and fighters and make low-altitude missions practical. Without the threat of enemy night fighters, the XXI Bomber Command could strip the B–29s of most of their guns and load more bombs instead.
Putting these theories to the test, LeMay directed a massive B–29 raid on the Japanese capital on February 25, 1945—a rehearsal for future incendiary raids. Striking a city four times as densely populated as the aver-age American city, 172 B–29s from three wings left twenty-eight million square feet of urban real estate in smoldering embers. The Tokyo raid proved the vulnerability of enemy cities to firebombing, although it did not produce the tremendously destructive firestorms of later B–29 attacks.
In March 1945, XXI Bomber Command employed the new incendiary tactics in five massive fire raids against some of the largest Japanese cities, including Tokyo, Nagoya, Osaka, and Kobe. During the Tokyo raid on the night of March 9/10, 279 B–29s flew in at altitudes of 4,900 to 9,200 feet. Three streams of bombers from three wings dropped almost 2,000 tons of firebombs while pathfinder aircraft illuminated the heart of the city.
In thirty minutes, the fires were out of control. Even if the Japanese had had more and better fire-fighting equipment, they would have been hard-pressed to combat the raging firestorms that boiled water in canals and melted the glass of store windows. Flames leaped waterways and fire-breaks and raced through a three-by-five-mile area. Updrafts even shook the bombers flying above the fires. The raiders could see the glow in the sky 150 miles away. This time the incendiaries burned out sixteen square miles of Tokyo, killing more than 83,000 people, injuring more than 40,000, and leaving up to one million homeless. No other single air raid in history had killed so many people. More than 267,000 buildings, as much as one-fourth of the city, burned down. The proper combination of factors, including weather, quantities of bombers, types of bombs, and formation patterns resulted in the annihilation of 18 percent of Tokyo’s industrial area and 63 percent of its commercial area. In contrast, the XXI Bomber Command lost only fourteen B–29s on the mission and forty-two other airplanes suffered damage.
The Twentieth Air Force raided Nagoya the night of March 11/12, 1945, with 285 B–29s; Osaka before dawn on March 14 with 274 B–29s; Kobe just after midnight on March 17 with 307 B–29s; and Nagoya again the night of March 18/19 with 290 B–29s. The five raids in ten days incinerated more than thirty-one square miles of densely populated urban area in four of Japan’s largest cities. Later in March, LeMay also directed the firebombing of Tachiarai, Oita, and Omura. By the end of the month, the XXI Bomber Command was running out of incendiary bombs.
The low-level night fire raids fulfilled the airmen’s expectations. Bomb loads on each airplane doubled. LeMay increased the number of missions per month, saved large amounts of fuel per mission, and lost fewer bombers. More aircraft bombed the new primary targets because those targets were so much larger: area bombing did not require much accuracy. Although analysts could not accurately gauge the destruction of Japanese industrial and military targets hidden in the cities, they could see in reconnaissance photographs how much area was destroyed. LeMay was succeeding where Hansell had failed. The March fire raids convinced the bomber commander that air power alone could force a Japanese surrender.
During April 1945, the XXI Bomber Command shifted its attention from major enemy cities to airfields on Kyushu. From there, suicidal Japanese kamikazes launched deadly ramming attacks against the U.S. fleet during the invasion of Okinawa (Operation Iceberg). Okinawa in the Ryukyu Islands was to be the home of new B–29 bases for the strategic bombardment of Japan. Between April 8 and May 11, 75 percent of XXI Bomber Command missions supported Iceberg. Regrettably, these airfield raids were not very effective because the enemy forces hid their fighters and quickly rebuilt the strips.
By mid-May, LeMay was happy to return his attention to the Japanese cities and their industries. He embarked on an “Empire Plan,” which allowed weather conditions to determine if the bombing raids would be precision or area strikes. The B–29s flew precision daylight missions in good weather and night incendiary raids when targets were obscured by clouds. Thus, LeMay retained the relevant portions of U.S. strategic bombing doctrine.
Incendiary bombing continued to produce the most destructive results. In May and June 1945, the XXI Bomber Command firebombed Japan’s six largest industrial cities, eliminating them as profitable targets. Seven of these raids involved formations exceeding 500 B–29s. On the night of May 23/24, no less than 520 B–29s—the largest number of Superfortresses sent against any Japanese city—struck Tokyo again. Two nights later, 464 B–29s returned to the Japanese capital with over 3,000 tons of firebombs. Almost seventeen square miles burned, and the Imperial Palace caught fire. Casualties, however, were lower than in the March raid because of evacuations to the countryside. Fifty-eight medium-sized cities and towns suffered next. A firestorm generated by B–29s at Toyama destroyed 99 percent of the city.
Throughout the onslaught, Japanese air defenses remained largely ineffective. U.S. B–29s could operate freely at lower altitudes because anti-aircraft fire was feeble at night and the enemy lacked a first-rate night fighter. Even so, enemy fighters downed twenty-six Superfortresses during the last fire raid on Tokyo the night of May 25/26, 1945, the highest single-day loss of B–29s in the war. A few days later, 454 B–29s struck Yokohama, this time escorted by more than one hundred P–51s from the VII Fighter Command on Iwo Jima. By the summer of 1945, LeMay was so confident his bombers could get through the Japanese fighter and anti-aircraft defenses that he began warning enemy cities that might be attacked through leaflet drops and radio broadcasts. Of course, he did not immediately strike every city warned, but the tactic did prove psychologically damaging and saved some lives.
The XXI Bomber Command devoted 75 percent of its sorties and tonnage to urban area incendiary attacks. Just as advocates had predicted, the fire raids destroyed many strategic targets that precision bombing had failed to hit: an estimated twenty-three major aircraft factories; six major arsenals; and a host of steel, petroleum, and gas plants. The Twentieth Air Force launched almost 7,000 B–29 sorties or flights on seventeen incendiary raids, dropping a total of 41,500 tons of firebombs. Only about 136 B–29s were lost to all causes during the incendiary campaign—a mission loss rate of less than 2 percent.