Imperial Japanese Army
The was the principal ground force of the Empire of Japan from 1871 to 1945. It played a central role in Japan's rapid modernization during the Meiji period, fought in numerous conflicts including the First Sino-Japanese War, the Russo-Japanese War, World War I, the Second Sino-Japanese War, and World War II, and became a dominant force in Japanese politics. Initially formed from domain armies after the Meiji Restoration, it evolved into a powerful modern military influenced by French and German models. The IJA was responsible for several overseas military campaigns, including the invasion of Manchuria, involvement in the Boxer Rebellion, and fighting across the Asia-Pacific during the Pacific War. Notorious for committing widespread war crimes, the army was dissolved after Japan's surrender in 1945, and its functions were succeeded by the Japan Ground Self-Defense Force.
History
Origins (1868–1871)
In the mid-19th century, Japan had no unified national army and the country was made up of feudal domains with the Tokugawa shogunate in overall control, which had ruled Japan since 1603. The bakufu army, although a large force, was only one among others, and bakufu efforts to control the nation depended upon the cooperation of its vassals' armies. The opening of the country after two centuries of seclusion subsequently led to the Meiji Restoration and the Boshin War in 1868. The domains of Satsuma and Chōshū came to dominate the coalition against the shogunate.Boshin War
On 27 January 1868, tensions between the shogunate and imperial sides came to a head when Tokugawa Yoshinobu marched on Kyoto, accompanied by a 15,000-strong force, some of which had been trained by French military advisers. They were opposed by 5,000 troops from the Satsuma, Chōshū, and Tosa domains. At the two road junctions of Toba and Fushimi just south of Kyoto, the two forces clashed. On the second day, an Imperial banner was given to the defending troops and a member of the Imperial Family, the Prince Ninnaji, was named nominal commander in chief, in effect making the pro-imperial forces officially an The bakufu forces eventually retreated to Osaka, with the remaining forces ordered to retreat to Edo. Yoshinobu and his closest advisors left for Edo by ship. The encounter at Toba–Fushimi between the imperial and shogunate forces marked the beginning of the conflict. With the court in Kyoto firmly behind the Satsuma-Chōshū-Tosa coalition, other domains that were sympathetic to the causesuch as Tottori, Aki, and Hizen emerged to take a more active role in military operations. Western domains that had either supported the shogunate or remained neutral also quickly announced their support of the restoration movement.The nascent Meiji state required a new military command for its operations against the shogunate. In 1868, the "Imperial Army" being just a loose amalgam of domain armies, the government created four military divisions: the Tōkaidō, Tōsandō, San'indō, and Hokurikudō, each of which was named for a major highway. Overseeing these four armies was a new high command, the Eastern Expeditionary High Command, whose nominal head was prince Arisugawa-no-miya, with two court nobles as senior staff officers. This connected the loose assembly of domain forces with the imperial court, which was the only national institution in a still unformed nation-state. The army continually emphasized its link with the imperial court: firstly, to legitimize its cause; secondly, to brand enemies of the imperial government as enemies of the court and traitors; and, lastly, to gain popular support. To supply food, weapons, and other supplies for the campaign, the imperial government established logistical relay stations along three major highways. These small depots held stockpiled material supplied by local pro-government domains, or confiscated from the bakufu and others opposing the imperial government. Local villagers were routinely impressed as porters to move and deliver supplies between the depots and frontline units.
Struggles to form a centralized army
Initially, the new army fought under makeshift arrangements, with unclear channels of command and control and no reliable recruiting base. Although fighting for the imperial cause, many of the units were loyal to their domains rather than the imperial court. In March 1869, the imperial government created various administrative offices, including a military branch; and in the following month organized an imperial bodyguard of 400 to 500, which consisted of Satsuma and Chōshū troops strengthened by veterans of the encounter at Toba–Fushimi, as well as yeoman and masterless samurai from various domains. The imperial court told the domains to restrict the size of their local armies and to contribute to funding a national officers' training school in Kyoto. However, within a few months the government disbanded both the military branch and the imperial bodyguard: the former was ineffective while the latter lacked modern weaponry and equipment. To replace them, two new organizations were created. One was the military affairs directorate which was composed of two bureaus, one for the army and one for the navy. The directorate drafted an army from troop contributions from each domain proportional to each domain's annual rice production. This conscript army integrated samurai and commoners from various domains into its ranks. As the war continued, the military affairs directorate expected to raise troops from the wealthier domains and, in June, the organization of the army was fixed, where each domain was required to send ten men for each 10,000 koku of rice produced. However, this policy put the imperial government in direct competition with the domains for military recruitment, which was not rectified until April 1868, when the government banned the domains from enlisting troops. Consequently, the quota system never fully worked as intended and was abolished the following year.The Imperial forces encountered numerous difficulties during the war, especially during the campaign in Eastern Japan. Headquarters in faraway Kyoto often proposed plans at odds with the local conditions, which led to tensions with officers in the field, who in many cases ignored centralized direction in favor of unilateral action. The army lacked a strong central staff that was capable of enforcing orders. Consequently, military units were at the mercy of individual commanders' leadership and direction. This was not helped by the absence of a unified tactical doctrine, which left units to fight according to the tactics favored by their respective commanders. There was increased resentment by many lower ranked commanders as senior army positions were monopolized by the nobility together with samurai from Chōshū and Satsuma. The use of commoners within the new army created resentment among the samurai class. Although the nascent Meiji government achieved military success, the war left a residue of disgruntled warriors and marginalized commoners, together with a torn social fabric.
Foundation of a national army (1871–1873)
After the defeat of the Tokugawa shogunate and operations in Northeastern Honshu and Hokkaido a true national army did not exist. Many in the restoration coalition had recognized the need for a strong centralized authority and although the imperial side was victorious, the early Meiji government was weak and the leaders had to maintain their standing with their domains whose military forces was essential for whatever the government needed to achieve. The leaders of the restoration were divided over the future organization of the army. Ōmura Masujirō who had sought a strong central government at the expense of the domains advocated for the creation of a standing national army along European linesunder the control of the government, the introduction of conscription for commoners and the abolition of the samurai class. Ōkubo Toshimichi preferred a small volunteer force consisting of former samurai. Ōmura's views for modernizing Japan's military led to his assassination in 1869 and his ideas were largely implemented after his death by Yamagata Aritomo. Aritomo has been described as the father of the Imperial Japanese Army. Yamagata had commanded mixed commoner-samurai Chōshū units during the Boshin War and was convinced of the merit of peasant soldiers. Although he himself was part of the samurai class, albeit of insignificant lower status, Yamagata distrusted the warrior class, several members of whom he regarded as clear dangers to the Meiji state.
Establishment of the Imperial Guard and institutional reforms
In March 1871, the War Ministry announced the creation of an Imperial Guard of six thousand men, consisting of nine infantry battalions, two artillery batteries and two cavalry squadrons. The emperor donated 100,000 ryō to underwrite the new unit, which was subordinate to the court. It was composed of members of the Satsuma, Chōshū and Tosa domains, who had led the restoration. Satsuma provided four battalions of infantry and four artillery batteries; Chōshū provided three battalions of infantry; Tosa two battalions of infantry, two squadrons of cavalry, and two artillery batteries. For the first time, the Meiji government was able to organize a large body of soldiers under a consistent rank and pay scheme with uniforms, which were loyal to the government rather than the domains. The Imperial Guard's principal mission was to protect the throne by suppressing domestic samurai revolts, peasant uprisings and anti-government demonstrations. The possession of this military force was a factor in the government's abolition of the han system.The military ministry was reorganized in July 1871; on August 29, simultaneously with the decree abolishing the domains, the Dajōkan ordered local daimyos to disband their private armies and turn their weapons over to the government. Although the government played on the foreign threat, especially Russia's southward expansion, to justify a national army, the immediately perceived danger was domestic insurrection. Consequently, on August 31, the country was divided into four military districts, each with its own chindai to deal with peasant uprisings or samurai insurrections. The Imperial Guard formed the Tokyo garrison, whereas troops from the former domains filled the ranks of the Osaka, Kumamoto, and Sendai garrisons. The four garrisons had a total of about 8,000 troopsmostly infantry, but also a few hundred artillerymen and engineers. Smaller detachments of troops also guarded outposts at Kagoshima, Fushimi, Nagoya, Hiroshima, and elsewhere. By late December 1871, the army set modernization and coastal defense as priorities; long-term plans were devised for an armed force to maintain internal security, defend strategic coastal areas, train and educate military and naval officers, and build arsenals and supply depots. Despite previous rhetoric about the foreign menace, little substantive planning was directed against Russia. In February 1872, the military ministry was abolished and separate army and navy ministries were established.