From Boardrooms to Brutality: Zaibatsu Power and Wartime Atrocities in Manchuria

Gabriel Fermin

​From their humble nineteenth-century births to their twentieth-century zeniths, Mitsui and Mitsubishi became major drivers in the forces of Japanese imperialism. The Zaibatsu, Japan’s powerful family controlled industrial and financial conglomerates, seized their most profitable financial opportunity with the outbreak of the Second Sino-Japanese War in 1937, as wartime demand fueled massive industrial expansion and military contracts. In the years leading up to the conflict, particularly between the establishment of Manchukuo in 1932 and the February 26 Incident of 1936, Japan saw the creation of its war infrastructure through rapid industrial expansion. Decades of Zaibatsu support for right-wing ultranationalist militarism and ethnic supremacy over other Asians had directly contributed to Japan’s transformation into one of the three fascist states comprising the Axis Powers during World War 2. Just like its counterparts in Germany and Italy, Japan engaged in some of the most egregious human rights abuses of the 20th century. Among these were the use of biological & chemical weapons, brutal prison and labor camps, and the use of "hellships" in the transportation of prisoners of war (POWs). Japanese activities in Manchuria were particularly infamous, details of which have been written about in works including Factories of Death: Japanese Biological Warfare 1932-45 and the American Cover-up by historian Sheldon H. Harris, Guests of the Emperor: The Secret History of Japan’s Mukden POW Camp by historian Linda Holmes, and Mitsui: Three Centuries of Business by historian John G. Roberts. Details of key imperial activity can be further corroborated through the official South Manchurian Railway Company (SMR) documentation First through Sixth Report[s] On Progress in Manchuria.

​Shiro Ishii and the Origins of Japan’s WMD Research

As stated earlier, Japan executed a massive buildup of military industrial power in the years leading up to the beginning of the Second Sino-Japanese War. Between 1932 and 1936, Japanese Manchuria saw tremendous development within industries such as steel, coal mining, gold mining, oil refining, alcohol manufacturing, shale oil production, liquefaction of coal, magnesium & aluminum mining, machinery manufacturing, chemical development, explosives manufacturing, and numerous other industries. Furthermore, according to political theorist, journalist, and suspected Communist spy T.A. Bisson, “After 1937 the flow of investment capital was channeled ever more rigorously into the munitions and strategic industries.”
World War II is infamous for the widespread manufacturing of weapons of mass destruction: weapons of biological, chemical, and nuclear nature. Japan’s foray into using these weapons began with the former Surgeon Major Shiro Ishii. Having acquired his medical degree in December of 1920 and completed military training in April of 1921 as a Surgeon-First Lieutenant, Ishii began to rapidly rise through the ranks of the Japanese military. In 1924, Ishii was sent back to Tokyo University by his superiors for further advanced training, he received a doctorate in microbiology in 1927; his thesis was titled “Research on Gram Positive Twin Bacteria.” Like many of his fellow young officers, he became attracted to the growing fascist movement within Japan: “Ishii openly supported the ultranationalists, espousing their anti-capitalist, anti-bourgeois, anti-liberal, and pro-National Socialist views.” It was during this time that Ishii became enamored with the concept of biological and chemical warfare through his acquisition of a report written by a professor who attended the 1925 Geneva Disarmament Convention, “which outlawed, at least on paper, both chemical and biological warfare.” When Ishii’s superiors were unconvinced by his early advocations, he set off in April 1928 for a two-year international research tour to gather evidence to change their minds. His travel destinations included, “Singapore, Ceylon, Egypt, Greece, Turkey, Italy, France, Switzerland, Germany, Austria, Hungary, Czechoslovakia, Belgium, Holland, Denmark, Sweden, Norway, Finland, Poland, the Soviet Union, Estonia, Latvia, East Prussia, Hawaii, Canada, and the mainland of the United States.” Returning to a Japan in 1930 that was significantly more aggressive than before in regards to its foreign policy, Ishii immediately began using his influence to lobby for Japanese usage of WMDs. In late 1931, he wrote to his superiors, “due to your great help we have already achieved a great deal in our bacteria research. It is time we start to experiment. We appeal to be sent to Manchukuo to develop new weapons.”

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​The Beginnings of Experimentation

Harris, the author of the Factories of Death, stated that, “Ishii was appointed as a Professor of Immunology at the Tokyo Army Medical School” upon returning to Tokyo and was also promoted to the rank of Major. Ishii relentlessly lobbied and advocated to his superiors over the next two years. A Ishii argued “that biological warfare must possess distinct possibilities, otherwise, it would not have been outlawed by the League of Nations.” Ishii accrued support among powerful right-wing figures such as “Col. Tetsuzan Nagata, chief of military affairs; Col. Yoriniichi Suzuki, chief of 1st tactical section of Army General Staff Headquarters; Col. Ryuiji Kajitsuka of the medical bureau of the army; Col. Chikahiko Koizumi, the Army's surgeon general; and the Minister of the Army and later as Education Minister Sadao Araki.” Ishii was perfectly positioned during the swelling of fascism in Japan to be provided with significant resources to further his biological and chemical research goals. His greatest opportunity came with the Japanese invasion of Manchuria beginning in 1931.
    The Japanese army occupied Harbin within Manchuria on February 5th, 1932. Ishii arrived in August 1932 with a team of scientists to establish a research center in the city commonly known as the Togo Unit. According to Harris, “Ishii often remarked: “There are two types of bacteriological warfare research, A and B. A is assault (Angriff) research, and B is defense research. Vaccine research is of the B type, and this can be done in Japan. However, A type research can only be done abroad.” Per his views, the initial facility at Harbin was deemed by Ishii to be “adequate for B, or innocuous research.” However, it soon became clear to Ishii that a separate isolated facility was needed for an A site to maintain the covert nature of the research: the town of Beiyinhe was selected as Ishii’s A site for aggressive research. Known colloquially as the Zhong Ma Prison Camp, the initiation of the Beiyinhe facility by Ishii was an important development in the progression of the Japanese war machine because it marked the beginning of large-scale human experimentation on behalf of the Japanese army on the Chinese.
    With an annual budget of 200,000 yen, a large amount for that time, Ishii went to work in Beiyinhe. Harris describes Ishii and his men as having “roared into the village, forcefully evacuated all the inhabitants and burned most of the buildings… Local Chinese peasants were drafted to construct buildings on the site… With the traditional arrogance the Japanese militarists displayed toward colonials, they brutalized the Chinese laborers during the process of constructing the new facility.” The Zhong Ma Castle was built to house 1000 inmates, and Ishii ensured its tiny cells were filled to maximum capacity. Here, Ishii and his team experimented on Chinese prisoners with diseases such as plague, anthrax, glanders, and cholera. Harris notes that even though much of the official record was destroyed by Japanese officials in 1945, there still exists enough information through existing records and survivor testimonies to paint the activities at Zhong Ma. For example, a peer of Ishii named Endo Saburo is recorded to have conducted experiments on prisoners with poison gas, liquid poison, electrical impulses, phosgene gas, and potassium cyanide. Ishii aroused interest when he conducted tests on frostbite with “humans who repeatedly were frozen and then defrosted.” The team would also mutilate prisoners to inspect or conduct experiments on severed limbs or organs, such as the brain. The total loss of life in Beiyinhe is unknown.
    The Zhong Ma facility was forced to close in 1934 because of a prison riot and was completely abandoned in 1937 when Ishii ordered all of its research and equipment transferred to a new location in Pingfang and the facility itself destroyed. This new location was where Ishii was appointed Chief of the Kwantung Army Anti-Epidemic Water Supply and Purification Bureau in 1936, which was soon known as Unit 731.

Slave Labor

Hideki Tojo (right) with Nobusuke Kishi, the key architect of Manchukuo during 1935–39.

​With World War II on the horizon, it was clear that Japan sought to use the virtually limitless supply of Chinese citizens as both test subjects for experiments and slaves for labor, which is not dissimilar to Adolf Hitler’s plan to deport a part of the Slavic population to East Russia for slave labor. After American entry into World War 2, the Japanese began to also use captured American prisoners-of-war in their labor camps.
    The origin of Imperial Japanese labor camps is closely tied to Unit 731. In 1936, the same year Emperor Hirohito created the Bureau and appointed Ishii as its head, Mitsubishi subsidiary Manchu Kosaki Kai Kibasha Ki Kaisha (MMK) purchased a factory from Ford Motor Company to use for its manufacturing. This factory was located in Mukden, less than 200 miles away from Unit 731 in Pingfang. To reiterate, the Japanese were quick to destroy most of the official records regarding these operations, and unlike our knowledge of Nazi Germany’s activities, much of what we know about the Kwantung Army’s most deeply nefarious activities in Manchuria come only from survivors’ testimonies. Using evidence that does exist, especially the operation of Zhong Ma, it’s not unreasonable to assume that the Japanese had been engaging in slave labor with the Chinese before American POWs made their way into such camps. Mukden later was the location for the Hoten Camp that housed American POWs. Since Mukden was already the location for wide-ranging Chinese internment and experimentation, the Japanese using the Chinese slave labor does not seem out of the question.
    The chairman of Mitsubishi and the managing director of Mitsui, Kiyoshi Goko and Suhin Ikeda, were detained by the US military, but a directive had already been issued throughout their companies and the military to destroy “all documents which would be unfavorable to us in the hands of the enemy.”

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Works Cited
First-Sixth Report[s] On Progress in Manchuria.
Bisson, T. A. (1945). Increase of zaibatsu predominance in wartime Japan. Pacific Affairs, 18(1), 55. https://doi.org/10.2307/2752026 
Harris, S. H. (2002). Factories of Death: Japanese biological warfare, 1932-1945, and the American cover-up. Routledge. 
Wu, T. (n.d.). Review of Japanese biological warfare and unit 731. https://zzwave.com/cmfweb/wiihist/germwar/731rev.htm 
HOLMES, L. G. (2024). Guests of the emperor: The secret history of Japan’s Mukden POW Camp. NAVAL INSTITUTE PRESS.