Memorandum by the U.S. Army Air Force Planners
Québec, 20 August 1943.
Enclosure to CCS 323
Air Plan for the Defeat of Japan
The provision of an appreciation producing an outline plan to direct the full aerial resources of the United Nations to bring about, in conjunction with other military and naval effort, the overwhelming defeat of Japan not later than 12 months after the defeat of the Axis powers in Europe.
It is assumed that:
a. The defeat of the Axis powers in Europe has been accomplished in the fall of 1944.
b. Russia and Japan maintain a state of neutrality.
c. China continues as an active and cooperative Ally, furnishing ground forces which, in conjunction with U.S. Tactical Air Forces, serve to secure the unoccupied portions of China.
d. The capacity of the air, road and pipeline facilities for “over the hump” transportation is to be first devoted to requirements of the 14th Air Force and the Chinese Army.
e. During the period in question, October 1944 to August 1945, inclusive, United Nations naval, air, amphibious and ground operations in the North, Central, South and Southwest Pacific, in Burma and the Bay of Bengal areas, are maintaining constant and increasing pressure against enemy forces. United Nations submarines, in increasing numbers, continue to harass and destroy enemy shipping.
f. North and North Central Burma are cleared of the enemy and occupied in 1944; and all of Burma in 1945.
To accomplish, by a combined aerial offensive, the destruction of the Japanese military, industrial and economic systems to such a degree that the nation’s capacity for armed resistance is effectively eliminated, within 12 months after the defeat of Germany.
a. To accelerate the destruction of selected systems of critical Japanese industry, the accomplishment of which will reduce the Japanese war effort to impotency.
b. Among the intermediate, nevertheless the most important objectives, is the neutralization of the Japanese Air Force, by combat, and through the destruction of aircraft factories, and the reduction of Japanese shipping and naval resources, to a degree which permits an occupation of Japan.
To reduce Japanese capabilities of resistance to a point which, within 12 months after the defeat of Germany, will force the capitulation or permit the occupation of Japan, requires the launching of an effective bomber offensive against vital targets on the main islands not later than the fall of 1944. Only such an offensive can, at a sufficiently early date, reach and destroy the vital elements of Japan’s transportation structure, and the nerve centers of her economic, military and political empire.
In view of the political, economic, military and transportation situation in the USSR, and more particularly the degree of industrial and economic development in Far Eastern Russia, the vulnerability of supply lines connecting it with Western Russia, and the consequent logistic difficulties which would probably be encountered in supporting air forces in substantial strength in the Maritime Provinces, it is unwise at this time to plan United Nations bomber offensive operations against Japan from bases in that area.
The islands of the Pacific within effective bombing range of the vital industrial areas of Japan, do not afford adequate bases for our air forces which will be available in 1944-45. Upon information now available, it appears that the only land area affording such bases with adequate capacity and dispersion, within 1,500 miles of the Japanese target area, immediately available for development, is on the Chinese mainland.
The beginning of the air offensive against Japan cannot await the opening of the ports of Hong Kong and Wenchow by the difficult and necessarily slow penetration of the enemy’s far flung and well defended defensive positions to the south and east thereof. Naval advances from the south and east will, however, be greatly facilitated and expedited by preliminary air offensive operations against the industrial and transportation targets on the island of Honshu.
It is evident that if a bomber offensive is to begin in 1944 from bases in China, the movement of all troops, organizational equipment and supplies in the base areas must initially be accomplished by air from India.
The transportation of such personnel, equipment and supplies may be accomplished by the employment of approximately 4,000 B-24 airplanes converted to cargo airplanes and tankers. The project will require a flow of approximately 596,000 tons per month through the port of Calcutta. (See Section 1, Enclosure “A”). Calcutta port facilities are at present adequate to handle 960,000 tons per month. Construction of additional facilities in that port will however not be required immediately.
A most important factor in planning for the air attack on Japan from the west, is the necessity for providing adequate protection of the air bases against the violent Japanese reaction which is certain to follow the large-scale development of those bases, and initiation of the use thereof. The pressure being exerted by our operations against Japanese forces in outlying Pacific areas in Burma and perhaps Sumatra, will substantially contain those forces, and prevent Japan from greatly reinforcing her air forces now deployed in China. Nevertheless, Japan will not readily accept the risk of loss of her already important, and potentially rich, newly acquired empire to the south. It is believed, however, that Chinese forces, reasonably equipped and supplied, aided in leadership, supported by the U.S. 10th and 14th Air Forces, will be able to defend the air base areas. Chinese forces and U.S. Tactical Air Forces, essential to provide such defense, will be available. Logistic support for them is dealt with in a subsequent paragraph. The initiation of the bomber offensive, and even measures in preparation therefor, will tremendously stimulate Chinese morale and unify the Chinese people under the leadership of Chiang Kai-shek.
A brief outline of the logistical implications of the proposed plan is contained in Enclosure “A.”
B-29 heavy bomber aircraft possess a tactical radius of 1,500 miles with a bomb load of ten tons, and are the best suited aircraft for the bombing of Japan from available bases. B-29 tactical units shown in Section 2 of Enclosure “A” will be available for deployment in China for operations against Japan on the dates indicated.
Studies conducted within the U.S. Army Air Forces indicate that 28 B-29 groups, of 28 airplanes each, conducting five missions per month on a 50 percent operational basis, for a period of six months, or a total of 168 operating group months, can accomplish the degree of destruction required to accomplish the Over-all Objective, described in paragraph 4, above.
Seventy-five percent of the selected strategic targets in Japan lie between Tokyo and Nagasaki. Substantially, all of this objective area is within 1,500 miles of a region in unoccupied China, the center of which is Changsha, within an approximate 800 miles radius of Kunming (See Map, Appendix “A”).
The area 400 miles north and south of Changsha, within this zone, is suitable for the development of VLR bomber airfields, and many old unimproved fields exist in the region. Operations of B-29 aircraft from this area would bring the majority of the selected strategic objectives within effective tactical radius.
From a source of supply in the Calcutta area, 200 heavy bomber aircraft of the B-24 type, stripped of armor, armament, and other equipment not essential to transport service, can support one B-29 group operating against Japan from bases in this area, at the rate set forth in paragraph 14.
Such B-29 type airplanes would transport gasoline, bombs and other required supplies directly from the port of Calcutta to Kunming, using the latter area as a staging center, before proceeding with a capacity load to the B-29 operating base zone.
A minimum striking force of 100 B-29 airplanes is desirable to conduct effective strategic bombing operations against Japanese mainland objectives. The availability of ten B-29 groups in the base area will permit sustained operation by such striking forces. Ten B-29 groups will be available for deployment in China by October, 1944.
2,000 B-24 type aircraft, converted to transports, would be required to support such operations from Calcutta supply bases. This number of aircraft, so converted, could be made available in the Calcutta area by October, 1944.
Aircraft availability schedules shown in Section 2, Enclosure “A,” indicate that a total of 20 B-29 groups will be available for deployment in China by May, 1945, and could be maintained at normal strength thereafter.
The same schedules indicate that the 4,000 B-24 type aircraft required for conversion to transport functions to maintain these 20 B-29 groups, can also be made available in the Calcutta area by May, 1945.
Operations by the 10-20 groups of B-29 aircraft which will be available, at the rate set forth in paragraph 14, would total 182 operating group months by 31 August 1945 at which time it is estimated that the degree of destruction of Japanese resources essential to crush the enemy’s capacity for effective armed resistance will have been fully accomplished.
Such operations, while weakening and demoralizing the enemy, will vastly encourage our long-suffering Chinese allies, and inspire them to increased and united effort to eject the enemy from their homeland, and hasten complete victory.
During the summer months of 1945, B-29 groups based on the Aleutian Islands could effectively attack parallel strategic Japanese objectives located in the northern part of the Empire.
Air Bases. A report on air base requirements and availability is contained in Section 3, Enclosure “A.” Sites, materials and labor required for construction of Chinese and Indian air bases are locally available.
Preparation of the necessary bases and other facilities for these operations must be initiated at least one year prior to October, 1944.
Other Supply Routes into China. The supplies brought into China from the west by the Air Transport Command, by pipeline, or by overland transportation, would be available for equipment and support of Chinese Ground units and supporting Tactical Air Forces (the latter provided by the USAAF, with limited augmentation by Chinese Air Units). The Tactical Air Force required to be furnished by the USAAF, will be available. The indicated volume of such supplies during the period in question is set forth in Section 4, Enclosure “A.” Such balance of supply as is available beyond the requirements of the above forces will serve to reduce the demands of the B-29 strategic Air Force upon the special type of air transport support set forth herein.
Concept of the Operation
a. Phase I. October 1944-April 1945. Sustained B–29 precision bombing attacks throughout the period to accomplish the destruction of selected strategic Japanese industrial systems, including aircraft factories and ship yards.
b. Phase II. May 1945-August 1945. An all-out attack against the other selected strategic objectives within tactical radius, integrated with attacks upon complementary objectives in Northern Japan by two B-29 groups based in the Aleutian Islands, to accomplish the destruction of Japanese resources which are an essential preliminary to an occupation of the Japanese homeland by United Nations forces.
The destruction of Japanese resources to such a point that the enemy’s capacity for effective armed resistance is substantially exhausted can be accomplished by sustained bombing operations of 10-20 B-29 groups based in an area of Unoccupied China within 1,500 miles of the center of the Japanese industrial zone.
Such operations can be supplied by 2,000-4,000 B-24 type aircraft, converted to transports, based at Calcutta, supplying the operational bases after staging at Kunming.
The required air striking and supply forces will be available.
Adequate air and ground defense forces and the maintenance of such units will likewise be available.
The planning and preparation of air bases and other facilities essential for the execution of this plan should be instituted without delay.
The execution of this plan promises to vastly strengthen our Chinese Allies, and to bring about a decisive defeat of Japan within 12 months after the defeat of the Axis powers in Europe.
That the line of advance proposed in the “Air Plan for the Defeat of Japan” be approved; and that this appreciation and outline plan be submitted to the Combined Staff Planners for further study and detailed development.
That in consonance with the United Nations Overall Objective, and Overall Strategic Concept for the Prosecution of the War, action be initiated without delay and prosecuted with all practicable expedition, to complete the preparatory measures required to be taken, and to provide the facilities and air bases in expanded numbers and increased proportions, essential for the timely execution of this plan.