"One of the most neglected aspects of the history of Korea under Japanese colonial rule is the significant role of the drug trade during the colonial period. Korea emerged as a major producer of opium and narcotics in the 1920s, and in the 1930s became an important supplier to the opium monopoly created by the Japanese-sponsored Manchukou regime. The latter development sparked an international controversy due to Manchukou's unsavory reputation in connection with the illicit drug trade, and would later lead the International Military Tribunal for the Far East to identify Korea as the 'principal source of opium and narcotics at the time of the Mukden Incident and for some time thereafter.' Moreover, emigrant Koreans played an extensive role in drug trafficking in China, and especially Manchuria. This disreputable element of the Korean Diaspora was usually employed at the lowest rung of the drug trafficking ladder as poppy farmers, drug peddlers, or the proprietors of opium dens. As Japanese nationals, Korean drug traffickers were immune from prosecution by Chinese authorities due to extraterritoriality."