Preparations for an Air Campaign
Much like the European air war, the shift away from precision bombing against Japan resulted more from happenstance than design. Despite Army Chief of Staff General George Marshall’s November 1941 warning that Americans would “fight mercilessly” in the event of war, and that B-17S from the Philippines would “be dispatched immediately to set the paper cities of Japan on fire,” Marshall intended his admonition to deter Japanese military activity rather than to provide a blueprint for American actions.25 The United States had only thirty-five B-17S on the Philippines when Japan attacked on 8 December, and by March 1942 had fewer than thirty “Flying Fortresses” in Australia.24 The dramatic raid by Lieutenant Colonel “Jimmy” Doolittle’s sixteen b – 25s, launched from the aircraft carrier Hornet on r 8 April 1942, was an effort to bomb specific industrial and military targets in Tokyo even though most of the bombs fell on residential areas. Hap Arnold and his Army Air Forces commanders intended to conduct a sustained, high altitude, daylight, precision bombing campaign against Japanese industries once they could place a substantial bomber force within range of Japan’s home islands. The guiding strategy for a bomber offensive, Arnold insisted, would be the “destruction of Japanese factories in order to cripple production of munitions and essential articles for maintenance of economic structure in Japan.”25 Yet Arnold and his cohorts had little information on the nature of the Japanese industrial complex and its key components.
To fill that void, in March 1943 Arnold asked the Committee of Operations Analysts (coa) to identify the appropriate targets for an air campaign against Japan that “would knock [it] out of the war.”26 The coa, composed of civilian “experts” that included bankers and economists, as well as Army Air Forces officers, had directed their previous efforts to dissecting the key war-making components of Adolf Hitler’s Third Reich. The committee members began their examination of Japan in similar fashion by listing industrial linchpins that, if destroyed, would negate Japan’s capability to fight. By November, they determined that steel was a key strategic target, and noted that the destruction of six coke plants, essential to the production of steel, would “cause a reduction of 30 percent of total Japanese steel capacity for several months until new sources of fuel could be found.” Moreover, “the immediate effects upon the industrial process would be substantial. . . . It is believed that Japan’s power to wage war effectively would be gravely impaired probably within six months and certainly within one year after the destruction had occurred.”27
Steel was one of the six most important strategic targets identified by the coa; others included merchant shipping, aircraft factories, ball bearing plants, radar and radio facilities, and urban industrial areas. The coa did not stress one set of targets over the other, and the inclusion of “urban industrial areas” recognized the important contribution made by cottage industries to Japan’s war production—as well as the susceptibility of those areas to fire. “Japanese war production (aside from heavy industry) is peculiarly vulnerable to incendiary attack of urban areas because of the widespread practice of subcontracting to small handicraft and domestic establishments,” the coa report stated. “Many small houses in Japan are not merely places of residence, but workshops contributing to the production of war materials.”28 The coa recommended attacks against urban industrial targets between December and May to take advantage of probable weather conditions such as high winds that would maximize the damage from firebombs. The analysts also noted that striking many urban areas simultaneously might “overwhelm the relief and repair facilities of the country as a whole.”29
At first glance, the coa recommendation of “urban industrial areas” as targets appeared inconsistent with the notions of strategic bombing that had guided America’s initial planning for World War II air campaigns. Both awpd-i, developed before the United States entered the war, and AWPD-42, designed soon after the Eighth Air Force had begun bombing Hitler’s Europe, stressed precision attacks against key centers of production to wreck Axis war-making capability. Army Air Forces planners intended those raids to achieve rapid, efficient results once the bomber force received the desired number of aircraft, crews, and logistical support. Japan’s industrial pattern, though, did not match Germany’s, and both awpd-i and AWPD-42 focused on the European war. The coa determined that Japan’s cottage factories were an important part of its industrial complex, and the only way to attack that component successfully would be through area bombing, awpd-i had not completely dismissed area attacks, and in fact had stated that such raids might occur late in the European war when German morale reached the breaking point.
By the time of the coa report on Japan, Ira Eaker’s Eighth Air Force—with Hap Arnold’s blessing—had begun using radar to area bomb German cities in attacks ostensibly aimed at industrial targets but actually designed to break German morale. In the case of Japan, the primary purpose of the coA-recommended attacks would be to wreck industry, although the raids would also kill large numbers of civilians. If the bombing worked as intended, it would provide the most efficient means possible to eliminate a key element of Japan’s production capability.
While the coa tried to identify Japanese targets, Brigadier General Orvil Anderson, the chief of the planning section of Arnold’s air staff, asked the intelligence branch to investigate how the Army Air Forces might best attack them with incendiary bombs. The subsequent October 1943 report compared German cities to those in Japan, observing that Japanese cities were more congested than their German counterparts and that Japanese residences were much more flammable. Combustible material in residential construction could serve as “kindling” for attacks that would also destroy factories and other necessities of war. The report created three categories of vulnerability that applied to Japan’s twenty major cities:
Zone I—Most Vulnerable Zone, the commercial center of the inner city containing the most residential congestion, greatest mix of residences and cottage industries, and an average population density of ninety thousand people per square mile; Zone II—Less Vulnerable Zone, less congested residential areas containing port facilities, rail yards, warehouses and some completely industrial areas with a population density of fifty-four thousand people per square mile; and Zone III—Non-Incendiary Zone, the suburban residential, park, and completely industrial areas, containing factories vulnerable to incendiaries but with fire-resistant business districts and low population density.30
aaf intelligence officers also estimated how many tons of bombs were required to destroy the two incendiary zones. They calculated that six tons of incendiaries per square mile would suffice to destroy Zone I completely, while the total destruction of Zone II would require ten tons per square mile. They did not consider Zone I more important than Zone II, because Zone II contained more factories that would affect war production. Zone I, though, contained more people, and its destruction would produce a significant indirect effect on Japan’s war effort by killing and dislocating its work force.31 The recommended instrument of destruction was the м-69 incendiary bomb, a 6.2-pound gasoline gel device tested against simulated German and Japanese residences at Dugway Proving Ground, Utah, between May and September 1943.32
Despite the attention given Japan’s “Urban Industrial Areas” as potential targets in late 1943, they were only one of many possible target categories, and the emphasis remained on precision bombing with that marvel of air power technology created by American engineering prowess, the в-29 “Superfortress.” The в-29 was the war’s most expensive weapon system at $3 billion, compared to the next costliest arms project, the $2.2 billion atomic bomb.
The Superfortress traced its roots to a 1939 Army Air Corps production board that had included Charles Lindbergh. Board members called for a heavy bomber with twice the range of а в-17, while Arnold demanded an aircraft that could attack targets two thousand miles away from its home base. Boeing won the contract and took two years to build a prototype, which first flew in September 1942.
The в-29 suffered from production delays and design problems, including four Wright R-3 50 engines prone to overheating, but contained unique features that made it a truly revolutionary design. The bomber sported the world’s first pressurized cabins (it had three—the cockpit, gunners’ compartment, and tail gunner’s compartment), enabling its eleven-man crew to fly at altitudes in excess of twenty-five thousand feet without having to wear the cold weather gear required by crews on B-17S or B-24S. The high operating altitude made the в-29 difficult for slow-climbing Japanese fighters to intercept. It had a top speed of 3 50 miles per hour, and a combat radius of 1,600 miles with twenty thousand pounds of bombs (roughly three times the bomb load of a в-17), which allowed it to attack targets in Japan from bases in the Marianas. It further possessed four gun turrets, remotely controlled via four General Electric analog computers, containing a total of twelve.50-caliber machine guns, plus a high-velocity 20 mm long-range cannon in the tail.33 awpd-i and AWPD-42 had both envisaged the в-29 for the European war, flying against Germany from bases in the United Kingdom and Egypt. The need for a heavy bomber that could fly the vast distances required to bomb Japan, combined with lagging в-29 production and the build-up of B-17S and B-24S in Europe, relegated the Superfortress to the Pacific theater.
There, the в-29 formed the mainstay of the Twentieth Air Force, created in April 1944 and directed from Washington DC, by Flap
Arnold. Arnold later claimed that the genesis for an independent bombing force in the Pacific under his command stemmed from his visit to bases in the region in autumn 1942.. “There was nothing else I could do, with no unity of command in the Pacific,” he contended. “It was something that I did not want to do.”34 That admission rang hollow, however. Arnold had no intention of allowing Army generals and Navy admirals to direct his high-priced bombers as auxiliary support for surface forces and divert them from their primary mission of destroying Japan’s vital centers.
The prospects for the B-29S to accomplish that independent goal received a substantial boost in late 1943 at the Sextant Conference of the Combined Chiefs of Staff. At this Cairo gathering, the Combined Chiefs approved the “Overall Plan for the Defeat of Japan,” which outlined grand strategy for the conclusion of the Pacific War. The document noted “the possibility that the invasion of the principal Japanese Islands may not be necessary and the defeat of Japan may be accomplished by sea and air blockade and intensive air bombardment from progressively advanced bases.” Planning for a possible invasion would continue “if this should prove necessary.”35 Arnold was determined that it would not be. After several discussions with his Joint Chief counterparts— including a session with the Chief of Naval Operations, Admiral Ernest J. King, in which Possum Hansell argued for an independent в-29 force36—the Joint Chiefs sanctioned the Twentieth Air Force. The new air force would operate directly under the Joint Chiefs with Arnold serving as “executive agent” to implement their directives. In actuality, the Army Air Forces Commanding General had secured control over his prized B-29S with minimum oversight, and had gained for himself his first ever combat command.
While he received limited interference from the Joint Chiefs in directing Twentieth Air Force, Arnold did have to contend with one higher authority—Franklin Roosevelt. In February 1943, the president proclaimed his progressive hope that air power might provide a relatively inexpensive victory in the Pacific. He called for the bombing of Japan to begin soon to prevent an American advance “inch by inch, island by island” that “would take about fifty years before we got to Japan.”37 Arnold promised that B-29S would begin bombing from China no later than March 1944, but that deadline did not satisfy Roosevelt. On 15 October 1943 the president wrote Marshall that he was “pretty thoroughly disgusted with the India-China matters. The last straw was the report from Arnold that he could not get the B-29S operating out of China until March or April next year.”38 Roosevelt continued to press for an air campaign against Japan from China that he thought would bolster the Chinese war effort. At the Sextant Conference in late November, the president formally committed American support to Chiang Kai-shek and his Chinese army, and the impetus for а в-29 campaign from Chinese bases increased. However, production delays and logistical difficulties shifted the new proposed start date for bombing to 1 May 1944.
Arnold was desperate to fulfill Roosevelt’s wishes, not just because they came from the president but also because he believed that the в-29 could make the decisive contribution to ending the Pacific War. His preference was to begin bombing from the Marianas once the Navy and Marines secured those islands. Roosevelt, though, had promised Chiang that American bombers would soon head his way. Until the capture of the Marianas, China offered the only friendly location from which B-29S could attack Japan—and even then, they had the range to strike only Kyushu, the southernmost main island.
When Arnold briefed Roosevelt in February 1944 on “Operation Matterhorn,” the projected в-29 assault on Japan from China, as well as on his plans to bomb from the Marianas, he noted that Japanese cities were especially vulnerable to fire. Yet he also remarked that he aimed to do more than simply create “uncontrollable conflagrations in each of them.” “Urban areas are profitable targets,” he observed, “not only because they are congested, but because they contain numerous war industries.”39 Roosevelt approved Arnold’s plan, as well as the provision that would make the Army Air Forces leader the Twentieth Air Force Commander.40 The president’s action heightened the increasing momentum to get the Superfortress into combat—and to obtain rapid results with it once it finally began operations. But as with the European war, the desire for fast results would ultimately overcome the progressive desire to minimize casualties among enemy civilians. From the perspective of those on the ground, a quick victory did not necessarily equate to fewer lives lost.
Despite Arnold’s zeal to begin bombing, numerous difficulties delayed the start of “Matterhorn.” Mass production of B-29S had finally begun in autumn 1943, yet deliveries occurred slowly, and many of the new bombers suffered from problems because of constant design changes. Only sixteen of the ninety-seven B-29S produced in January 1944 were flyable.41 To remedy the situation, Arnold created an array of “production modification centers” in central Kansas where design updates occurred en masse to the newly produced bombers; Boeing provided six hundred mechanics to assist. Once the B-29S received the necessary modifications to make them operational, their combat crews arrived and flew them to India—where they faced a new set of challenges to prepare them for their missions against Japan.