The incendiary raid on Tokyo of 25 February

On 25 February 1945 more than 170 American B-29 Superfortress bombers from the Marianas arrived over a snow-covered Tokyo. Instead of the aircraft plants that American crews had been aiming at in vain all winter, their target this time was the densely built-up city centre, and their bomb bays held mainly incendiaries. It was the largest raid yet by Major General Curtis LeMay’s XXI Bomber Command, and at the same time the first large-scale trial of the method that two weeks later reduced much of the Japanese capital to ashes.

Some popular chronologies of the war state that the bombers took off on 24 February. American records and Japanese tallies of air raids, however, date the whole attack to 25 February – the take-off from the Mariana Islands and the bombing took place on the same day. The discrepancy probably stems from the time difference: while bombs were falling on Tokyo, it was still 24 February in the United States, on the other side of the date line.

From precision targets to cities

From the first B-29 raid on Tokyo on 24 November 1944, the bombers from Saipan, Tinian and Guam had used against Japan the tactic of high-altitude daylight precision raids, aimed above all at the aircraft industry. The results were meagre. The jet stream at 8–9 kilometres broke up the formations and carried the bombs off course, cloud hid the targets on most days, and the Nakajima works at Musashino near Tokyo emerged from successive raids with little damage. In January 1945 the commander of the Twentieth Air Force, General Henry H. Arnold, relieved Brigadier General Haywood Hansell and handed XXI Bomber Command to LeMay, who had previously commanded the B-29s in India and China; the first raids under his command, however, brought no improvement.

In Washington another solution had long been under consideration. Staff analyses from 1943 pointed out that Japanese cities – built largely of wood and paper, with thousands of small workshops serving the armaments industry scattered among the houses – were exceptionally vulnerable to fire. Special M69 incendiary bombs filled with napalm, dropped in clusters, were manufactured for the purpose. The Twentieth Air Force headquarters pressed for trials of the weapon: on 4 February 1945 B-29s dropped mainly incendiaries on Kobe, causing serious damage to the city and its main factories. According to the official history of the US Army Air Forces (Wesley F. Craven and James L. Cate), in a new directive of 19 February the Twentieth Air Force headquarters raised the priority of incendiary raids on urban areas, treating them as the main complement to the attacks on aero-engine factories.

Target and forces

The circumstances of the raid of 25 February are described in two ways. According to American studies, it was a planned large-scale trial of incendiary bombing of Tokyo in line with the February directive. Japanese studies, and the accounts based on them, state that the bombers were originally to make another precision strike on the Nakajima works at Musashino, in conjunction with an attack by carrier aircraft, and that a forecast of cloud over the whole of Honshu led the command to switch the target to the city centre, while keeping the route and altitude. Both versions agree that the choice of incendiaries was deliberate – they made up about 90 per cent of the load.

According to Japanese tallies, 229 bombers took off from the Marianas – at the time the largest number in the history of XXI Bomber Command. For the first time three bombardment wings took part in a single raid: the 73rd from Saipan, the 313th from Tinian and the 314th, newly arrived on Guam, for which – according to unit histories – this was the first combat mission. According to American figures, 172 aircraft reached Tokyo and bombed (some sources give 174), dropping a total of about 450 tons of incendiary and fragmentation bombs.

Bombs through the snow

A snowstorm was raging over Tokyo. The bombers flew in daylight at high altitude, above the clouds, and bombed largely by radar. In the bad weather the formations broke up: according to Japanese descriptions, some bombers attacked in tight groups, others singly. The bombs fell mainly on the central and eastern districts of the city, around Kanda station, and the fires spread to a number of districts – from Kanda and Nihonbashi to Asakusa, Shitaya and Honjo.

According to American assessments, about 2.6 km² (one square mile) of the city and some 28,000 buildings were burned out or damaged. Japanese tallies record 195 killed, 432 wounded and 20,681 houses destroyed or damaged. According to Japanese studies there were fewer casualties than in the January raid on the Ginza area, but the damage to buildings was far greater than in any earlier attack on the capital. The fire also reached the grounds of the Imperial Palace: the buildings of the court stables burned down, and the Ōmiya Palace, the residence of the Empress Dowager, and the palace of Prince Chichibu, brother of Emperor Hirohito, were among those damaged.

In this weather the Japanese defences were almost helpless. Fighters could not intercept the scattered bombers above the clouds, and the anti-aircraft artillery fired blind. According to Japanese studies, the B-29s lost only two aircraft that day, and those in a mid-air collision. The lack of effective defence in the face of heavy destruction undermined the capital’s confidence in the military’s air defences, and the Japanese command concluded that it had to strengthen its radar so that the fighters could take off in bad weather, too.

On the same day aircraft of the US Navy returned over the Tokyo region. Vice Admiral Marc Mitscher’s carriers, which on 16–17 February had struck the Japanese capital for the first time and then supported the landing on Iwo Jima, again attacked airfields and aircraft plants in the Kantō region. For them, too, the snowstorm proved an obstacle: the attacks were curtailed, and a strike on Nagoya planned for the next day was cancelled.

LeMay’s conclusions

For LeMay and his staff the raid of 25 February was above all an experience. Compared with months of fruitless attempts to hit the engine factories, it produced a measurable result: square kilometres of burned-out buildings at minimal cost to themselves, and in weather in which precision bombing was impossible. At the same time it showed the limits of the tactics used so far – bombs dropped from eight kilometres by scattered formations spread too widely to start a fire engulfing whole districts. Further raids on aircraft plants at the end of February and the beginning of March again failed because of wind and cloud.

LeMay decided to change the method radically: to bomb at night, from low altitude, with aircraft flying singly rather than in formation, and to strip most of the defensive armament from the bombers in exchange for a heavier load of incendiaries. On the night of 9/10 March 1945 more than 300 B-29s attacked the eastern districts of Tokyo in this way. The fire consumed some 41 km² of the city and, by estimates, killed about 100,000 people – it was the most destructive single air raid in history. American planning documents gave the target area of Tokyo the code name “Meetinghouse”; according to Japanese studies, the raid of 25 February was the first attack on this area and the March raid the next.

Place in the war

The raid of 25 February 1945 closes the period in which the Americans tried to defeat Japanese war industry solely by precision attacks on factories. It was not yet a saturation raid of the March kind, but it was this raid that convinced the commanders of the Twentieth Air Force that fire destroyed Japanese cities, where war production was dispersed among residential buildings, more effectively than high explosive. After Tokyo came the turn of Nagoya, Osaka and Kobe, and from June of several dozen smaller cities; by the end of May more than half of Tokyo’s built-up area had burned. The incendiary campaign, waged from ever closer bases – helped also by Iwo Jima, then being captured, where B-29s could make emergency landings – cost the lives of hundreds of thousands of Japanese civilians. It remains controversial to this day: some historians see it as a necessary means of destroying dispersed war industry and hastening surrender, others as a deliberate blow against the civilian population, described in Japan as one of the greatest wrongs of the war.