The role of the China Burma India Theater (CBI) commander, Lieutenant General Joseph W. Stilwell, was restricted to the provision of logistical support and the defense of the bases.

The XX Bomber Command abandoned the logistically difficult and increasingly vulnerable bases in China in January 1945, and concentrated its resources on rail and port facilities in Indochina, Thailand, and Burma.

On 29 January 1940, the United States Army Air Corps issued a request to five major aircraft manufacturers to submit designs for a four-engine bomber with a range of 2,000 miles (3,200 km).

[1] Boeing devoted its plants in Renton, Washington and Wichita, Kansas to B-29 production; assemblies would later also be built by the Bell Aircraft Corporation in Marietta, Georgia, and the Glenn L. Martin Company in Omaha, Nebraska.

[6] Ostensibly, the B-29 was intended to defend the Western Hemisphere against encroachment by a hostile foreign power, but as early as September 1939, Colonel Carl Spaatz had suggested that it might be used to bomb Japan from bases in Siberia, Luzon or the Aleutian Islands.

[13] In March, the Assistant Chief of the Air Staff, Major General Laurence S. Kuter, initiated a detailed study of the possibility of using VLR bombers based in China.

[28] The timetable for the Central Pacific advance was revised in March 1944: Truk was to be bypassed and the Palau operation was postponed until 15 September, after the capture of the southern Mariana Islands, which was now scheduled to commence on 15 June 1944.

The COA had been created in December 1942, and its membership included officers from the Army and Navy, along with distinguished civilians consultants such as Edward M. Earle, Thomas W. Lamont, Clark H. Minor and Elihu Root Jr.

In a report delivered on 11 November 1943, they identified six priority economic targets: merchant shipping, steel production, urban industrial areas, aircraft plants, ball bearings, and electronics.

For his assistant chief of staff for operations (A-3), he secured Brigadier General LaVerne G. Saunders, who had been awarded the Navy Cross while in command of the 11th Bombardment Group during the Guadalcanal campaign.

The 444th Bombardment Group was led by Colonel Alva L. Harvey, who had been a test pilot for the Boeing B-17 Flying Fortress bombers and had participated in the first American bombing raid on Berlin.

Arnold had hoped that the B-29s would be ready by January 1944, but on 12 October 1943 he notified Roosevelt:In connection with the bombing of Japan from China by B-29s, I regret exceedingly to have to inform you that there has been a holdup in production of engines.

He personally reconoitered the Chengdu area in November 1943, and in his report on 8 December he selected four B-29 airbase sites, Xinjin, Guanghan, Qionglai and Pengshan, where existing runways could be strengthened and lengthened to accommodate the B-29s.

Eight bomb maintenance squadrons embarked from Los Angeles on the troopship USS Mount Vernon on 27 February and sailing via Melbourne, Australia, they reached Bombay on 31 March.

Nonetheless, the B-29 Hobo Queen, commanded by Colonel Frank R. Cook, flew to RAF Bassingbourn in the UK on 8 March as part of a deception plan that the B-29 would be deployed to Europe.

[d] Wolfe reported to Arnold on 26 April 1944 that: "The airplanes and crews got off to a bad start due to late production schedules, difficult modifications, inclement weather, and the sheer pressure of time necessary to meet the early commitment date.

[88] If shipped normally, they would not arrive in Karachi before May, so the U.S. Navy made the escort carriers USS Mission Bay and Wake Island available to deliver the first hundred P-47s; the remaining fifty followed on freighters.

Although a key feature of the Matterhorn plan was that the XX Bomber Command would support itself, this was impractical, and it had to fall back on the services of Brigadier General Thomas O. Hardin's India–China Wing (ICW) of the ATC.

[89] March was a difficult month for the ICW, with a gasoline shortage in Assam and the opening of the Battle of Imphal and operations in Northern Burma and Western Yunnan, which caused ATC aircraft and supplies intended for Matterhorn to be diverted to support of the ground forces.

[94] Lieutenant Colonel Robert S. McNamara's statistical section of the XX Bomber Command conducted a detailed investigation of the factors involved in the delivery of supplies to China.

[94] Seventy C-109s were added to the effort to supply the XX Bomber Command in September, flown by surplus B-29 crews, and in November 1944 the B-29s were withdrawn from the airlift entirely and the C-109s were transferred to ATC.

[53] The XX Bomber Command wanted to test out the new M18 incendiary bombs and the large number of wooden buildings and freight cars and a small oil facility in the area offered good targets.

[109] Eight journalists and three news photographers accompanied the mission,[110] which was led by Saunders, who, along with Engler, flew as a passenger on B-29 Superfortress 42-6274 Lady Hamilton of the 468th Bombardment Group, piloted by Captain Herman Sancken.

[113] Six bombers suffered minor damage from flak, and one was lost over Yawata, 42-6230 Limber Dragon, which was shot down by a Kawasaki Ki-45 night fighter piloted by Warrant Officer Sadamitsu Kimura.

[143] The Japanese fighters and antiaircraft guns failed to destroy any of the American bombers,[142] but B-29 Superfortress 42-24420 of the 444th Bombardment Group ditched when it ran out of fuel 90 miles (140 km) from Ceylon.

[156][157] B-29 Superfortress 42-93829 Cait Paomat received flak damage over Yawata and the pilot, Major Richard McGlinn, elected to bail out over the Soviet Union rather than Japanese-occupied China.

[167] On 11 October, LeMay received orders to discontinue the attacks on the petroleum and steel industries and concentrate on missions in support of the theater commanders such as shipping and aircraft and naval facilities.

[173][174] LeMay originally intended to stage a training mission on 4 October to hone his crews' skills in flying the new twelve-plane formations, but this had been postponed in favor of the attacks on Formosa.

[195] Arnold informed the Secretary of War, Henry L. Stimson, that more than 100 warehouses, factories and office buildings had been destroyed, and that the attack was a "vital factor in limiting the speed, effectiveness and scope of Japanese operations in China.

[212][213] On 24 November 1944, American bombers commenced raiding Japan from the Mariana Islands, making operations from the increasingly vulnerable and always logistically difficult China bases redundant.