Japanese Army 1939-40

Strength and organization of the Imperial Army and Air Force 1939 and 1940, before the Japanese entry in the Second World War.

Japanese soldiers crossing a pontoon bridge in China
Heavily-loden Japanese soldiers are pictured while crossing a pontoon bridge in China. They wear M98 field service uniforms and carry bolt-action 6.5mm Ariska rifles. The enormous distances which warfare in China necessitated were hard to cover, especially for an Army as unmechanized as the Japanese. Logistics were a constant problem.

Japanese Army before WW2

Japanese Lieutenant, 1937
Japanese Lieutenant, 1937, with the old-style service dress.
The Japanese Army was a mirror of Japanese society before 1945. It contained a peculiar amalgam of medieval attitudes and modern material, for the Army still followed the code of Bushido which upheld the virtues of man-to-man combat in a machine age, and demanded that the Japanese soldier die rather than surrender.

The political influence of the Japanese Army had substantially increased in the years between the two world wars. The Army saw Japan’s salvation in China: Japan should secure the vast resources of the Asian mainland by carving out for herself a continental empire. The Army consequently viewed the Soviet Union as Japan’s most dangerous enemy – a power which had traditional interests in North China. The Navy looked to the Pacific Ocean, and particularly to the South West Pacific, with the rich prize of Malaya and the Dutch East Indies as the means by which the resources vital to the maintenance of Japan as a great power could be seized. The Navy, therefore, regarded the world’s two greatest naval powers, Great Britain and the United States, as Japan’s most deadly enemies. It was no coincidence that the two services shaped Japan’s strategy to suit the exclusive capacity of either the Army or the Navy. Before 1941 the Army had most of its own way.

Japan seized Manchuria in 1931 and the province of Jehol in 1934. Three years later the Japanese Army embarked on a full-scale undeclared war against China. The Japanese aimed to destroy the Chinese Army in the field and thus bring the country to its knees quickly; this would avoid the colossal task of trying to conquer and hold the vast spaces of China. The Japanese generals failed. The Chinese Army was more elusive and remained intact, and Japan’s need to keep large forces on the Chinese mainland was a limiting factor on her strategy throughout World War II.

The peacetime strength of the Japanese army was 17 divisions.
By 1940 it had 2 divisions in Japan and Korea, 12 in Manchuria and 27 in China (total 41 divisions).

The Manchurian Army proper in 1939 had a strength of some 75,000 men in infantry and cavalry units.

Japanese ground-combat units

Basic Japanese fighting units:

Infantry DivisionArmored DivisionArmy Amphibious BrigadeNavy Naval Landing Force
Total units401??
Infantry regiments 3 (c. 2,500 officers and men each) 1 brigade (3,800 officers and men) 3 battalions with 3,200 officers and men 2,000 officers and men
Cavalry regiments 1 (950 officers and men)---
Total men? 10,500 4,000 c. 3,500
Machine guns 120 (just in MG companies) + ????
Howitzers and Field guns 66 (48 x 75mm, 18 x 70mm + independent field artillery companies) 12 (8 x 105mm, 4 x 155mm)? 8 (4 x 3inch, 2 x 75mm, 2 x 70mm)
Anti-tank guns 18 (37mm) 18 (47mm)??
Anti-aircraft guns? 20 (4 x 75mm, 16 x 20mm)??
Tanks 10-17 (tankettes)270--
Vehicles c. 300 1,580--

Army Air Force

Nakajima Ki-27
The Nakajima Ki-27 was the standard fighter of the Japanese army before the outbreak of the Pacific War. Here a Ki-27b 1938-39 in China.

There was no independent Japanese air force. The Army and the Navy each had their own air service. Each was nominally controlled by the Emperor. Actual control was vested in the General Staff, the Army and Navy Ministries and the Inspector General of Aviation.
The function of the Japanese Army Air Service was to provide support for the ground troops and to conduct counter-air force operations. It was not expected to initiate strategic operations on its own behalf, as was the case with the RAF for instance.

The Air Service was relatively small at the outbreak of war and Japan’s highly trained pilots were soon casualties. Their replacements lacked the necessary flying ability to take on the growing technical and numerical superiority of the Americans. Partly as a response to this shortage kamikaze aircraft were introduced. The kamikaze aircraft was simply an aimed bomb in which the pilot sat over an explosive charge and aimed the aircraft at the target. First used at Leyte Gulf, these planes caused some consternation to the American forces; but overall their effect was negligible to the final outcome of the conflict.

Japanese bomber crews in northern China
Japanese bomber crews in northern China before a mission. They are wearing the regulation issue summer flying uniform with rank insignia displayed on the left breast.
The Japanese Army Air Service was organized into five air armies with clear areas of operations. Coordination was achieved between the Army and the Air Service by placing the air forces in each theater under the command of the theater commander. The largest Japanese tactical organization was the air division, two or more of which would form an air army. Beneath this was the air brigade; two air brigades formed an air division. The composition of the brigade was flexible. Its HQ was small and concerned primarily with tactical planning. It was usually composed of three or four air regiments; each regiment was equipped with the same type of aircraft (fighters, or light or medium bombers) divided into three or four companies. The company was the most important operational unit; it was normally of nine aircraft, divided into three sections, each of three aircraft.

The total strength of the Japanese Army Air Service in 1940 was 36 fighter (324 planes), 28 light (252 planes) and 22 medium bomber (198 planes) and 29 reconnaissance companies (261 planes), with a personnel total of 33,000 officers and men.

References and literature

The Armed Forces of World War II (Andrew Mollo)
Luftkrieg (Piekalkiewicz)
World War II – A Statistical Survey (John Ellis)
Japanese Army of World War II (Philip Warner)

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