In 1939, what caused nearly 2 million Koreans to be forced into the labor force or the army?
Korea was considered to be part of the Empire of Japan as an industrialized colony along with Taiwan, and both were part of the Greater East Asia Co-Prosperity Sphere. In 1937, the colonial Governor-General, General Jirō Minami, commanded the attempted cultural assimilation of Korea's 23.5 million people by banning the use and study of Korean language, literature, and culture, to be replaced with that of mandatory use and study of their Japanese counterparts. Starting in 1939, the populace was required to use Japanese names under the Sōshi-kaimei policy. Conscription of Koreans for labor in war industries began in 1939, with as many as 2 million Koreans conscripted into either the Japanese Army or into the Japanese labor force.
Albrecht von Roon, the Prussian Minister of War from 1859 to 1873, put into effect a series of reforms of the Prussian military system in the 1860s. Among these were two major reforms that substantially increased the military power of Germany. The first was a reorganization of the army that integrated the regular army and the Landwehr reserves. The second was the provision for the conscription of every male Prussian of military age in the event of mobilization. Thus, despite the population of France being greater than the population of all of the German states that participated in the war, the Germans mobilized more soldiers for battle.