Military conscription was first established in Meiji period Japan by a set of Conscription Acts in 1872-1873, and later revised in 1883. This established the first citizen army in Japan - the Imperial Japanese Army - and the first organized in service to the nation-state in the modern sense of the term. Men of all classes were conscripted into service for a period of three years.
The chief figures involved in pushing for the institution of conscription included Ômura Masujirô and Yamada Kengi of Chôshû, and Tani Kanjô of Tosa. They saw conscription not only as a means by which to strengthen the country's defenses against outside attack, but also as a means of strengthening it against uprisings against the new government. A centralized military would also help guard against regional governors gathering power and becoming regional warlords.
E.H. Norman argues that these men were well aware of elements within the Meiji government, and new-formed military, who still believed strongly in samurai ideals, who believed that commoner/peasant troops could not be as loyal and dutiful nor as skilled in combat as the samurai, people who might lead pro-feudal revolts against the new government in order to restore samurai rule if they were rubbed the wrong way. They were to be proven right, as the 1870s saw numerous samurai uprisings of this sort, particularly in Kyushu, culminating with the Satsuma Rebellion in 1877.
References
- Norman, E.H. Soldier and Peasant in Japan: The Origins of Conscription. New York: Institute for Pacific Relations, 1945. pp41-42, 49.