The Japanese Army that waged World War II emerged in the 1870s and 1880s during the rapid modernizing period of the Meiji Restoration. Into World War II it retained some pre”C20th-century ideas and a unique military culture that had roots in bushidō and in other samurai and premodern traditions and views of honor and death in combat. However, that idea should not be exaggerated: in most ways, the Japanese Army emulated the most modern armed forces of the Western world. New shotai (rifle troops) and Kiheitai (shock troops) were shaped into a modern army in the 1860s by Yamagata Aritomo and his Choshu clan disciples, later reinforced by men of the Satsuma clan. The leading clans used modern troops to defeat an only partly reformed army of the Tokugawa shoguns. Over time, these two traditionally dominant clans removed the samurai class from its superior position in the officer corps, replacing many non-Satsuma or Choshu clan samurai-men tied to other feudal and local clan loyalty groups-with a new officer class that was drawn most often from the rising middle classes, men tied more closely to emerging national institutions. In 1878 a General Staff was established on the Prussian model. Ten years later the Army shifted from a regimental and garrison system to a more modern divisional system. Lower ranks were conscripted principally from the middle and lower classes. Officers and men were imbued with national ideals, from the Emperor Cult and state Shinto to the racialist idea of shido minzoku. French military advisers were important in the early years of change and reform. They were increasingly replaced by German advisers before World War I, a trend that persisted prior to World War II. Despite self-conscious modernism and a new professionalism, the Japanese Army that entered the 20th century still relied on an old idea of “seishin” (“human spirit”) as the driving force behind its tactics and doctrine. That was not especially unusual: most modern militaries heading into the wars of the 20th century retained elements of their premodern warrior ethic, spirit, and origin. In the 1930s the fascist states in Europe would revert to comparable emphasis on “will” and martial or racial “spirit” over material factors in war.
The new Army was tested in the first Sino-Japanese War (1895), during which it swept aside less modern Korean forces and Chinese Qing armies that still fielded some units of archers. After sharp battlefield victories in Korea, the Japanese Army demonstrated what became a pattern of harsh occupation that would mark its history for the next half century, though with important exceptions. Another encounter with Chinese troops occurred when Japan agreed to join an international expedition to suppress the Boxer Rebellion in 1900. During that conflict the Japanese Army was actually the only force to abstain from revenge atrocities against the Chinese. The Japanese Army fared less well militarily during the Russo-Japanese War (1904-1905), taking terrible casualties around Mukden in particular. Its structural weaknesses were covered up in propaganda that celebrated the Imperial Japanese Navy ‘s triumphs at Port Arthur and the Tsushima Strait. Marginal Japanese victory over Tsarist Russia in the war as a whole had contradictory psychological effects on the Army. On one hand, Japanese military thinkers exaggerated the victory and thereby overestimated national military prowess. On the other hand, a deep fear of Russia was confirmed that would underlie Japan’s diplomatic and military policies through 1945, and even after that.
Another pattern became evident in Japanese military policy upon the outbreak of World War I: Japan’s leaders saw war in Europe as presenting opportunities to make gains in Asia at the expense of European colonial empires. Japan quickly entered the war, taking over German possessions in China and the Pacific. In 1914 the Japanese Army was small, but as modern as any other. It struck against the German concession in China, at Qingdao (Tsingtao) in Shandong. It fought well in Shandong, but not well enough to warrant Tokyo making “Twenty-One Demands” in 1915 that would have reduced all China to vassal status. Over the next three years the Army remained relatively small by world standards. It prepared to fight quick and decisive battles, where armies of the Great Powers evolved into mass forces geared to waging attritional warfare. Most importantly, at the Paris Peace Conference, Japan’s diplomatic ambition outpaced its military capabilities, leaving its leaders isolated, embittered, and with feelings of having been cheated of the due spoils of victory in war. Again, that reaction was replicated in Europe, where Italians notably evoked angry denunciations after 1919 of the “mutilated victory” that supposedly cheated Italy of its just reward of other peoples’ territory.
The 1920s saw growing civilian opposition to bloated military budgets and more lower-class Japanese avoiding conscription. In 1924 the first real cuts were made to the Army since its founding-four full divisions-to pay for modernizations. It is therefore widely thought that after World War I the Japanese Army faced a dilemma: it needed to invest in more modern technology but lacked the financial resources and technical expertise to make the transition. Some historians argue that the Army turned away from technology it could not afford to embrace “spiritual training” and fantastical ideas about the unique and special power of the Japanese national spirit to overcome a European-style (or American-style) Materialschlacht . This shift included posting officers to public schools to ensure martial and imperial indoctrination of the young. In that sense, around the new professionals much of the old Meiji value system survived. On the other hand, Leonard Humphreys argues persuasively that during the 1920s the old Meiji system was displaced by a new “imperial army system” in a reform process that raised up new factions not tied to the old Meiji clans. Instead, by the end of the 1920s the most important factions within the Army were organized around shared professional views about how and where to fight future wars. The most important of these factions was the Issekikai, whose members came to dominate the Guandong Army in Manchuria, and eventually also the General Staff. From 1931 even Issekikai officers split into Kodo-ha and Tosei-ha factions whose bitter arguments and conflicts roiled the entire Japanese government through the mid-1930s. These officer cliques provided most of the military prime ministers as well as field commanders who led the Army into a long war in China, then a world war that spread Japanese forces across Southeast Asia and the Pacific.
Many things changed after 1926 as the Army reasserted a leading role in Japanese politics and foreign policy. An important factor in driving Army thinking was a perpetual budgetary struggle with its great rival, and even opponent, the Imperial Japanese Navy. The conflict went far beyond interservice rivalries normal in all national militaries. It would ultimately produce extraordinary irrationalities in the Japanese war effort until total military defeat arrived in 1945, as Army-Navy rivalry led to astonishing duplication in war planning and production. Japan’s military leaders would mutually hoard oil and other vital raw materials, refuse to coordinate on weapons design, and most disastrously, follow divergent grand strategy and operational planning. A round of bitter infighting was set off when Issekikai radicals in the Guandong Army assassinated Zhang Zuolin, the “Old Marshal” and warlord of the north of China and Manchuria. That was the first of several key steps that drew Japan into protracted war with China. The next was the Mukden incident on September 18, 1931, which led to unauthorized conquest of Manchuria by the Guandong Army. That had the unintended consequence of provoking massive anti- Japanese boycotts and riots in China. On January 28, 1932, anti-Japanese rioting in Shanghai was met by ruthless Japanese bombing of part of the city, then by the IJN landing marines (Rikusentai ). The Guomindang fought hard and threatened to overmaster the outnumbered marines. The Army reinforced with 50,000 men, forcing a truce on Jiang Jieshi after defeating his forces inside the city. On either side, the “Shanghai incident” forebode a much wider war to come. The Kodo-ha faction reacted by embracing the idea of war with China. Its radical “war now” agenda led to an attempt to seize power in Japan in 1936, in a rebellion known as the “February Rising.” Opposition from the Tosei-ha faction, and refusal by most troops to obey the rebel officers, ended the February Rising in great disgrace and led to executions of 19 young plotters. Enemies of the Kodo-ha then purged other mutinous young officers and thereby partially restored Army discipline and unity under a newly centralized command.
Japanese Army officers were not all samurai. The majority of Army officers came from a range of socioeconomic backgrounds. As early as 1907 fewer than 50 percent were samurai in class origin. By 1931 only about 15 percent were samurai by class, while fully one-third came from the lower middle class. Along with the disappearance of samurai domination, the old regional basis of the Meiji army waned as officer cadets were trained from the age of 14 in six military schools set up on the Reichswehr model. The best cadets graduated into the central Military Academy at Ichigaya, where they studied for qualifying exams and learned still deeper devotions of the Emperor cult. Specialist training followed at an Infantry School at Chiba. The true elite went on to the Staff College. While regional dominance of senior commands by Choshu officers continued into the 1930s, more important informal associations of officers emerged in which men aligned by training or ideology. The most notable were Issekikai with their Kodo-ha and Tosei-ha factions, but there were other more fanatic groups known as the “Blood Pledge Corps” and “Young Men’s Patriotic Storm Troops.” Such personal loyalty cliques meant the Army was almost impossible to control, with different disobedient factions assuming a moral right and duty to set national policy through mutiny and by force. There also developed a wide gulf between senior officers of the General Staff and Imperial General Headquarters who thought about a total war strategy, and the majority of lesser and more junior officers who cleaved to a highly aggressive 19th-century ethic of decisive battle through “l’offensive a outrance.” The gulf was partly bridged by developing mobile strike forces for future fighting in Manchuria and Siberia. Overall, by the early 1930s the officer corps was contentious, faction-ridden, impatient with civilian authority, and ready to make aggressive war. It had a tradition of officers on the scene outside Japan ignoring and even disobeying orders from Imperial General Headquarters. That tendency would repeatedly draw the Army as a whole, and the Japanese state and people, into military commitments that the Army alone should not have made and could not meet. Simultaneously, the Army declined in general professional competence as it expanded from 24 divisions in 1937 to 51 divisions by 1941. That rapid expansion meant many new officers were not as well trained as older ones, a fact that began to show in the field as early as the first year of the Sino-Japanese War (1937-1945).
A strategy of garrisons and reliance on conscripted civilians in uniform to hold new territorial gains made in China strained old Army identities while eroding established offensive doctrine. On the other hand, the Japanese Army in China had to adapt like other armies to new realities of industrial warfare, facts which militated against blunt infantry assaults in favor of speed and mobility. To facilitate this need in any future war with the Soviet Union, which was thought the most likely next conflict, the Army adopted a three regiment structure for its divisions, replacing the old quadrangular structure. Where earlier Army tactics called for a division to attack in two columns of two regiments each, new doctrine emphasized that one regiment should attack frontally, the second must probe the enemy’s flank with an eye to envelopment, while the third was held in reserve to exploit any breakthrough or effected encirclement. The main point was to draw the enemy forward toward the attacking main column, then envelop and destroy him in a battle of annihilation. Although first tried in the field in China, the new infantry doctrine maximized what the Japanese saw as their primary skills and advantages- ferocious fighting spirit married to short-range weapons-when confronted with a Western or Soviet enemy capable of bringing vast advantages in matériel to battle. Other close-in fighting skills were to be used in infiltration along the flanks by smaller units, noisy diversionary assaults, and attacking in successive waves that leapfrogged positions to maintain the momentum of attack. These tactics proved most effective in night-fighting, for which the Japanese Army trained hard and was far more effective than any of its enemies. Nevertheless, some historians sharply criticize Japanese Army command and operational skills as blunt, primitive, and inflexible. When one adds a compounding strategic policy that was reckless rather than bold, and that badly overextended Army capabilities, protracted stalemate in China followed by grinding defeat in the Pacific start to look foreordained.
From 1939 the Japanese Army in China suffered from growing lethargy and ill-discipline among fresh conscripts, as well as the usual desuetude of an occupation force stuck in a strategic quagmire. Adding to the burden was a remarkable level of moral and fiscal corruption at an institutional level as the Army sought to develop and exploit territories it occupied. Notably, the Army partially funded operations through a drug empire run out of the occupied territories. It imported heroin from Europe and raw opium from Iran before the war, expanding on ancient drug trades operated from Korea, Taiwan, Manchuria, and southern Chinese ports. A League of Nations report concluded in 1937 that 90 percent of all illegal drugs sold globally originated with the Japanese. As Japan lost access to European and American markets for its export of heroin and morphine, thousands of “opium dens” were set up in China’s cities and in Indochina. Japanese soldiers using these drugs were severely punished: the addictive drug trade was for Army profit and to undermine and humiliate the Chinese and other occupied peoples; its temptations were forbidden to Japanese. The Army also ran prostitution rings and other felonious enterprises across Asia, in partnership with local criminal gangs or client regimes. Prostitution on a grand scale was run at an official level for Japanese soldiers as well as for the Army’s profit. In addition to outrages inflicted on kidnapped or coerced non-Japanese Ianfu in rape camps in China and Korea, tens of thousands of Japanese girls were lured and imported to Manchuria and Inner Mongolia upon signing five-year prostitution contracts with the Army.
In 1936 Army conscription in Japan produced only 170,000 men per annum. From that point forward the rate of conscription was repeatedly increased as the huge manpower drain of war in China was felt. By the end of 1939 nearly half a million Japanese were casualties of the China War, a conflict for which they were relatively well-trained and equipped but badly overstretched. By 1941 the Japanese Army had 2.25 million men in uniform and under arms. Half were in Manchuria or northern China. The other half were scattered in occupation garrisons across Korea and on Taiwan, or held in reserve on Army bases in Japan. Another 4.5 million men were registered in the reserve. Despite those impressive numbers, when the Army agreed to the Navy’s nanshin (“southern offensive”) strategy in July 1940, it was wholly unprepared for the jungle fighting it agreed to undertake in the South Pacific and Southeast Asia. Weapons and doctrine had been developed to fight on the great dry plains of northern China, Manchuria, Mongolia, and Siberia, not the fetid jungles of Burma or the Solomons. An effort was made to correct this equipment deficiency in 1941, during war games and with some training on Hainan Island. But the training was limited and proved inadequate. Japanese soldiers were therefore asked to fight a new war in distant and alien environments for which they had little tropicalized equipment, precious few medical or other field resources, and almost no specialized training or knowledge. They also knew little about the new enemies they faced and fell back on cultural and racial stereotypes to make up the deficit. Fortunately for ordinary Japanese soldiers, their enemies were no better prepared for jungle fighting at the start. Later in the war, each side fought with hard-gained tactical and environmental experience. However, Japanese defenders by then faced severely adverse conditions of a matériel imbalance that had tipped decisively in favor of their enemies.