by Kelly Suen
Unit 731 was a biological and chemical weapons research and development unit of the Japanese Army. It operated covertly for ten years since 1935 in Harbin, China, and was responsible for some of the most notorious war crimes committed by Imperial Japan, due to its extensive use of lethal human experimentation. With science and medicine as its stated purpose, Unit 731 was called upon to develop cures for sexually transmitted diseases, which had begun to spread among the Japanese army due to soldiers’ rape of civilians and sex with comfort women. To study STDs, Unit 731 prisoners were used as human test subjects. Female prisoners, for example, were infected by syphilis either by forced sex with an infected male prisoner or by injections. These women were forced to become pregnant for use in STD experiments, and the babies born to these women were also used in experiments.
Pregnant women were infected with syphilis and other STDs for use in studying the effect it may have on the fetus. Female prisoners were systematically raped, sometimes by doctors, resulting in a large number of babies born in captivity. Babies born to women with syphilis were tested on the moment they were born. These babies were personally delivered by doctors instead of nurses, as it normally would be the case. Blood flow from mother to child would be stopped and released intermittently to take multiple blood samples. This was done to determine the intensity of syphilis transmitted from mother to child, and to study the progression of the disease from the time of birth.
Some women were forced to have sex to study the transmission of STDs. When the infection of STDs by injection was abandoned, the researchers started forcing prisoners to have sexual intercourse with each other. The process was handled by four or five Unit 731 members, dressed in white laboratory clothing which would cover the body entirely, leaving only eyes and mouth visible. A male and female, one infected with syphilis, would be brought into a cell together and forced to have sex with each other, under threat of getting shot if anyone resisted. Once the healthy partner was infected, researchers closely observed the progress of the disease to determine, for example, how far it advanced the first week, the second week, and so forth. Instead of looking for external changes, such as the condition of sexual organs, researchers performed live dissections to investigate the effect of the disease on the internal organs at different stages of the disease. Unsurprisingly, some women were impregnated from these sexual encounters.
Babies, whether born outside or in Unit 731, were also made use of in experiments. The ones born in Unit 731 were the results of rape. A few months after being impregnated, women would be dissected and their fetuses removed while they were awake. On one occasion, a pregnant woman was infected with syphilis, and when her child was born, they were both dissected. Another experiment conducted on children was for a frostbite cure. A temperature sensing needle was inserted into the hand of a three-month-old baby and the infant was immersed in ice water, then temperature changes were recorded.
With the prevalence of syphilis and other STDs among Japanese soldiers, Unit 731 was sought out to create cures. Unit 731 performed experiments that had caused the deaths of many female prisoners. Atrocities such as vivisections and forced pregnancies were committed for science. Women were infected with syphilis, and some were also forced to become pregnant. They were infected and impregnated by rape or forced sex with male prisoners. Scientists utilized pregnant women as well as the children they would later give birth to in their STD experiments. Pregnant women, women with syphilis, and babies were dissected alive. Despite knowledge of a large number of children born in Unit 731, there are no records of survivors. It is likely the children were killed along with other prisoners at the end of the war.
Unit 731: Japan's Secret Biological Warfare in World War II by Peter Williams, David Wallace pg. 41
Unit 731: Testimony By Hal Gold
Get our ebook to learn more about Unit 731!
by Jack Gray
The Japanese Imperial Government Disclosure Act of 2000, another name for Title VIII of the Intelligence Authorization Act of 2000, authorized the process of locating, declassifying, and publishing documents relevant to war crimes committed by the Imperial Japanese Army during World War II. Previously, the majority of research on World War II was focused on Nazi war crimes as President Clinton had created the Nazi War Criminal Records Interagency Working Group (known as the IWG) in 1998 to “to locate, inventory, recommend for declassification, and make available to the public all classified Nazi war criminal records.”
The researchers of the IWG felt there was a need for additional research into Japanese war crimes, and asked permission to expand their activities to include this topic. Samuel Berger, Assistant to the President for National Security Affairs at the time, informally granted this request, which was later officially confirmed by President Bill Clinton. In 2000 the IWG was formally renamed the Nazi War Crimes and Japanese Imperial Government Records Interagency Working Group, and asked government agencies to examine their records for documents which could be relevant to Japanese war crimes. Specifically, they asked for (1) any materials related to Japanese Treatment of prisoners of war and civilian internees, including any materials related to forced or slave labor, (2) any materials related to development and use of chemical and biological warfare agents, (3) any materials related to General Ishii (the commanding officer of Unit 731), (4) any materials related to the U.S. Government decision after the War not to prosecute the Emperor and certain war criminals, and (5) any materials related to the so-called “Comfort Women” program, the Japanese systematic enslavement of women of subject populations for sexual purposes. This is why many of the war crimes are still being researched as the declassification didn't happen until the 2000s.
After reviewing each department’s inventory, the IWG estimated that there were about two hundred thousand pages of documents that could be released—a far cry from the ten million pages of documents relating to Nazi war crimes. The reason for this disparity is different departments of the U.S. government have documents pertaining to different aspects of the war; the Department of the Army had greater autonomy over the Pacific theater and kept their own records, gradually releasing them during the 1970’s and 1980’s, whereas in Europe the Office of Strategic Services (the OSS) was largely in charge of intelligence, and had more stringent protocols for releasing documents. However, conventional intelligence agencies like the OSS and later the CIA (its successor) did play a role in the Pacific Theater. For example the Office of Strategic Services kept records about Japanese chemical and biological warfare and crimes against both civilians and prisoners of war, while the CIA kept records on Japanese intelligence efforts before and during the war.
In addition to the recently released documents, there are many documents that have been available to the public since the end of the war. Most of these are transcripts or evidence from the International Military Tribunal for the Far East, which prosecuted individuals such as Tojo Hideki, prime minister of Japan during the war, General Yamashita Tomoyuki, who conquered Malaysia and the Philippines, or Lieutenant General Homma Masaharu, who commanded the Bataan Death March. Prosecutors used over 4,000 documents as evidence against the 28 defendants.
Furthermore, many Japanese records from the war have been translated into English, thanks to the Allied Translator and Interpreter Section under General MacArthur, who were responsible for gathering and analyzing Japanese documents during and after the war. Unfortunately, many Japanese documents were destroyed by the Japanese themselves in an attempt to protect their leaders from prosecution for war crimes. More were lost when the U.S. government agreed to return a number of documents to Japan in the 1950’s and 1960’s.
Although originally directed to complete their mission in one year, the IWG continued to work until April 2007, when they presented their final report to Congress. They declassified 1.2 million pages of documents relating to Nazi and Japanese war crimes. However, they considered their greatest accomplishment to be their proving that declassification of intelligence documents would not have drastic negative consequences, as was previously thought. U.S. intelligence services had long resisted the release of confidential information, concerned that it would endanger current efforts and operations, but the IWG felt they had shown that the release of historical documents would have no negative effects.
The IWG also drew other large conclusions from their efforts. They showed that the reopening of documents and files is a massive, expensive, time-consuming effort, and recommended that all agencies continually review and follow protocols for declassifying their records instead of having to do large projects to search through decades of unopened files. The reason that these documents remain classified for so long after they became irrelevant was that there was a lack of public interest in Japanese atrocities before and during World War II. However, the stories of survivors and witnesses gradually gained momentum until the 1990’s, when a group of comfort women (women who were forced by the Japanese government to be prostitutes for Japanese soldiers) filed a lawsuit against Japan. In addition, Congress passed a resolution demanding that Japan issue both an apology for the crimes they had committed and pay compensation to surviving victims. However, Japan has never issued a formal apology, and did not provide restitution to their victims.
The documents released thanks to the efforts of the IWG will be resources for researchers and historians who can shed greater light on this dark period of history. Hopefully by learning from the crimes of the past we can prevent any similar atrocities in the future.
This small book provides introductory essays to some of the more useful sources on Japanese war crimes that were released thanks to the Disclosure Acts.
Most of the released documents themselves can be found on the National Archives Website at https://www.archives.gov/
National Archives. "Japanese Interim Report: an Interim Report to Congress." https://www.archives.gov/iwg/reports/japanese-interim-report-march-2002-1.html#highlights.
National Archives. "Declassified Documents: Berger Memorandum, February, 1999." https://www.archives.gov/iwg/guidance/berger-memorandum/berger-memo-dec-2000-2.html.
National Archives. "Interagency Working Group Title 8, Intelligence Authorization Act." https://www.archives.gov/iwg/about/iwg-title-8.html.
U.S. Congress. Nazi War Crimes & Japanese Imperial Government Records Interagency Working Group Final Report to the United States Congress. April 2007. https://www.loc.gov/rr/frd/Military_Law/pdf/NaziWarCrimes_Japanese-Records.pdf
by Sophie Hammond
In 1936, the Japanese built Unit 731—the administrative center of the top secret biological warfare project of the Imperial Japanese Army—in the isolated Pingfang District of the city of Harbin in Manchuria. At the time, Harbin was a city with a large Russian minority population, and writer Morimura Seiichi has hypothesized that of the 3,000 prisoners experimented on at Unit 731, up to 30% were Russian.
Harbin was built in the late nineteenth century as part of the Russian Empire’s colonizing effort. In 1896, China sold Russia the right to build the Chinese Eastern Railway across Manchuria, from the city of Chita in Eastern Siberia to the city of Vladivostok, an important Pacific port for the Russian Empire. This deal made Harbin, where three train lines now met, a major rail hub. Immediately an influx of Russian engineers, refugees, and criminals began. The relationship between the new immigrants and the Asian ethnic groups already living in Manchuria was rarely smooth—according to anecdotes, some of the arriving Russian soldiers would shoot out of train windows at locals as they sped past. Later came Russian Jews, to whom the Czar promised freedom from anti-Semitic laws if they served as Russian colonists in Manchuria. Anti-Communist White Russians fled to Harbin en masse during and after the Russian Civil War. By 1922, the Russian population of the city had soared to over 100,000. Artists, writers, and political refugees created a cosmopolitan, Russianized culture in the city they called their “Paris of the Far East”.
After the Bolshevik Revolution, the Chinese and the Soviets fought over who should run the Chinese Eastern Railway. In 1924 China and the Soviet Union agreed to manage the CER together, with the Soviet Union acting as the dominant partner. Soviet citizens emigrated to Harbin to work on the railroad and caused friction with the White Russians already working there. Over most of the next decade, China and the Soviet Union battled for control over the railroad, and by extension, over Harbin.
These disputes ended when Japan invaded Harbin in 1931. The Soviet Union sold the CER to Japan four years later, and thousands of Soviet railroad employees left Harbin. Non-Soviet Russians also emigrated quickly. By 1939, some sources say that only 28,000 Russians lived in Harbin. Russians who stayed often faced the loss of their jobs to Japanese settlers and were vulnerable to arrests by the Kempeitai, a branch of the Imperial Japanese Army who patrolled the streets of Harbin like a police force. They had the power to arrest anyone accused of being a Communist sympathizer, an anti-Japanese saboteur, a spy, or a “vagrant”. Fearing the charge of vagrancy, some Russian families never let their children leave home after 5 pm.
Unit 731 got the vast majority of their Russian prisoners from those Russians arrested by the Kempeitai. Most prisoners of Unit 731 were brought there after having been charged and convicted of capital crimes, usually without even the pretense of a trial. However, when the supply of victims was running low, the Kempeitai were authorized to send even “vagrants” straight to Unit 731.
Very little information remains about who these Russian victims were or what they suffered. One account mentions a Russian mother and daughter trapped in a gas chamber, the mother frantically trying to shield her daughter from breathing in the gas as researchers safely on the outside of the chamber timed their convulsions. A Japanese Youth Corps member training at Unit 731 gave later testimony that among the subjects for syphilis testing were two Russian women with their children, a girl of four or five and a boy of six or seven. A former Unit 731 medical worker stated that he once saw a white man cut length-wise and pickled in a six-foot-high jar of formaldehyde, a man the worker assumed was Russian. Some of the Russian victims were not actually citizens of Harbin but Soviet prisoners of war captured in border skirmishes. One researcher later admitted to being personally responsible for the deaths of at least forty Soviet citizens in experiments at Unit 731. While details are far and few between, it is certain that all of the Russians held prisoner in Unit 731 suffered greatly and that none of them survived. In the last days of the war, any remaining prisoners were killed and buried.
In the end, it was the Soviet Union, in response to so many Soviet and Russian victims, who subjected the Unit 731 researchers they had captured to an open trial for war crimes. The other researchers made a deal with United States occupation authorities for immunity in exchange for their research data. The Khabarovsk War Crime Trials of 1949 found all eight Japanese researchers and four military servicemen guilty of biological warfare and sentenced them to work in Soviet labor camps for two to twenty-five years. As part of a political compromise, the remaining Japanese prisoners were released and returned to Japan in 1956, and historian Sheldon Harris thinks it is likely that the researchers gave the Soviets information about Unit 731’s research data in exchange for leniency. But while the week-long Khabarovsk Trials were at least partly for propaganda purposes, Harris in his book Factories of Death accepts the accuracy of their findings, saying, “Evidence introduced during the hearings was based on eighteen volumes of interrogations and documentary material gathered in investigations over the previous four years. Some of the volumes included more than four hundred pages of depositions....Unlike the Moscow Show Trials of the 1930s, the Japanese confessions made in the Khabarovsk trial were based on fact and not the fantasy of their handlers.”
To learn more about Unit 731 itself, see these blog posts:
And check out Pacific Atrocities Education’s book about Unit 731: http://www.pacificatrocities.org/unit-731-ebook.html
Clurman, Irene, and Dan Ben-Canaan. “A Brief History of the Jews of Harbin: How a Manchurian Fishing Village Became a Railroad Town and a Haven for Jews.” JewishGen KehilaLinks, JewishGen, 2007, kehilalinks.jewishgen.org/harbin/Brief_History.htm.
Dreyer, Jacob. “Ghost Town: Searching for Remnants of Russia in the Chinese City of Harbin.” The Calvert Journal, 20 Aug. 2014, www.calvertjournal.com/opinion/show/3018/russia-china-harbin-legacy.
Gold, Hal. Unit 731 Testimony. Tuttle Publishing, 2011.
Harris, Sheldon H. Factories of Death: Japanese Biological Warfare, 1932-1945 and the American Cover-Up. Routledge, 2002.
Kristof, Nicholas D. “Unmasking Horror—A Special Report.; Japan Confronting Gruesome War Atrocity.” The New York Times, The New York Times, 17 Mar. 1995, mobile.nytimes.com/1995/03/17/world/unmasking-horror-a-special-report-japan-confronting-gruesome-war-atrocity.html.
Lisenko, Alexander. “Harbin—A Russian Enclave in Manchuria.” The Orthodox Vision, 2006, pp. 4–10.
McCurry, Justin. “Unit 731: Japan Discloses Details of Notorious Chemical Warfare Division.” The Guardian, Guardian News and Media, 17 Apr. 2018, www.theguardian.com/world/2018/apr/17/japan-unit-731-imperial-army-second-world-war.
Morimura, Seiichi. The Devil’s Gluttony. Kobunsha, 1981.
Nie, Jing-Bao. “The West’s Dismissal of the Khabarovsk Trial as ‘Communist Propaganda’: Ideology, Evidence and International Bioethics.” Journal of Bioethical Inquiry, vol. 1, no. 1, Apr. 2004, pp. 32–42., doi:10.1007/bf02448905.
Pawlowicz, Rachel, and Walter E. Grunden. “Teaching Atrocities: The Holocaust and Unit 731 in the Secondary School Curriculum.” The History Teacher, vol. 48, no. 2, Feb. 2015, pp. 271–294., www.societyforhistoryeducation.org/F15Preview.html.
by Sophie Hammond
Unit 731 was the administrative center of the top secret biological warfare project of the Imperial Japanese Army. Located in rural Manchuria, at that time a puppet state of Japan, and known by the codename “the Epidemic Prevention and Water Purification Department”, Unit 731’s purpose was, in fact, to cause epidemics and contaminated water—for the enemy. The Imperial Japanese Army was fighting multiple wars and needed to win all of them. To do so, they turned to biological warfare.
The Geneva Protocol of 1925 banned biological and chemical warfare in international armed conflicts in order to prevent the outbreak of another war on the magnitude of World War I. The Japanese delegation in attendance at the conference had signed the agreement, but since the Japanese Diet did not ratify the agreement, Japan was not bound by the Geneva Protocol. Several countries who had ostensibly agreed to the Protocol were developing their own weapons in secret, and Japan was no exception.
The human test subjects of Unit 731 were criminals, political prisoners, Communists, or civilians—usually pregnant women, children, and the elderly—who were considered useful for experiments and were rounded up under trumped-up charges. Seventy percent of these victims were Chinese, while others were Korean, Mongolian, and Russian, and a few might have been Allied prisoners of war. They were called marutas by the researchers, or “logs”, because the local Manchurians were told that the facility was a lumber mill. Research findings discovered at Unit 731 were occasionally published in peer-reviewed scientific journals, where the articles claimed the experiments had been performed on Manchurian monkeys.
Whether these prisoners were called logs or monkeys, their human suffering was immense. One of the most common experiments at Unit 731 was the vivisection of diseased bodies. Researchers found the most virulent strains of disease by infecting prisoners, usually by injecting them with “vaccines” or feeding them contaminated food, and killing those prisoners who recovered quickly from their illnesses. They then injected the more potent bacteria and viruses from the sickest prisoners into the next “generation” of victims. For researchers who wanted to view a more natural progression of disease, some prisoners were kept locked in cages in the same room as plague-infested mice and fleas to see how long it took for them to become infected. The prisoners were then sliced open so that researchers could see how the disease affected living organs. This vivisection was done without anesthetic, to ensure results untainted by any external factors. Vivisections were also commonly performed on pregnant women—many of whom were pregnant by rape.
The researchers were especially interested in the pregnancies of women with syphilis. The Japanese military was struggling to combat the syphilis sweeping through its ranks, likely due to the rape of civilian women and of the comfort women forced to service the military. At first the researchers tried to inject prisoners with syphilis, but seeing that this yielded few results, they turned to raping them. Two prisoners, one infected with syphilis, were placed in a room together along with armed guards and made to have sex with each other. Once the previously healthy partner contracted syphilis, they would be inspected periodically to see the progression of the disease, culminating in a vivisection to see what syphilis did to the organs and—in the case of pregnant prisoners—the baby. Vivisection was practiced on Chinese citizens at many other government-sponsored research facilities besides Unit 731. For a time, it was considered the most effective way to train young Japanese medical students to perform surgeries correctly.
Unit 731 researchers also experimented with methods of treating frostbite. Prisoners were taken outside in freezing weather, sometimes after being dipped in water, and kept there until their limbs were frozen solid. Artificial cool air currents accelerated the freezing. A Japanese officer who watched one of these experiments stated later that frostbite was considered achieved if, when struck, the prisoner’s limbs made a sound like a wooden board. Sometimes prisoners were left to thaw, their arms and legs turning gangrenous until they rotted. Usually, however, frostbite victims were immersed in water at various temperatures to see which temperatures cured frostbite the fastest. It’s from these tests run by Unit 731 that the world knows the most effective way to deal with frostbite—not to rub the affected limbs, but to immerse them in water between 100 and 122 degrees Fahrenheit.
But the main research aim of Unit 731 was to develop the most effective biological warfare weapons. At a testing ground called Anda, prisoners were lashed to stakes and suffocated with poison gas or forced to wait while planes dropped plague bombs—bombs full of plague-infested fleas—over them. Prisoners were also used to test the effective range of flamethrowers, chemical weapons, and bombs, including bacteriological bombs. The resulting shrapnel of these weapons was often infected with various diseases, so that researchers could discover how long it would take people to die from being hit by flying shrapnel only. Unit 731 helped develop balloon bombs, which were sent to float across the Pacific to the United States and cause destruction and terror. Only a few ever actually arrived in the United States and went off, and while American news outlets were requested not to report on these bombs for fear of causing mass hysteria, there were at least seven verified American victims.
Unit 731 was also instrumental in planning an army operation which was never carried out, Cherry Blossoms at Night, which involved infecting San Diego with the bubonic plague using kamikaze pilots. This operation was halted in large part, it seems, by the intervention of Hideki Tojo—a man the United States later hanged for his other war crimes. Other contributing factors to the failure of Cherry Blossoms at Night were the Japanese surrender in August 1945 (Cherry Blossoms at Night was planned for September) and the necessity near the end of the war for the Japanese to focus on defense rather than offense.
China wasn’t so lucky. Using knowledge developed from Unit 731 tests, the Imperial Japanese Army created plague bombs and had airplanes spray diseases like bubonic plague, cholera, and anthrax over Chinese cities, killing hundreds of thousands of people. Plague outbreaks, for example, were reported in Changde in north-central China and Ningbo in eastern China. Between three and four hundred thousand Chinese people are estimated to have been killed by this method of biological warfare.
Unit 731’s other experiments included injecting prisoners with animal blood and horse urine, heating them until they died, spinning them with centrifuges until they died, and locking them in pressure chambers until their eyes popped out. It’s estimated that about 3,000 people died from the tortures they underwent at Unit 731.
After the war, the American government helped cover up many of the atrocities the Japanese military committed during the war. The masterminds of Unit 731 were granted immunity during the Tokyo Trials in exchange for handing over what data existed on the Unit 731 experiments. Many of those affiliated with Unit 731 enjoyed long and illustrious medical careers. Three Unit 731 researchers became the president of the Japan Medical Association, the head of the Japan Olympic Committee, and the Governor of Tokyo.
In April 2018, a nearly complete list of the 3,607 people who were employed by Unit 731 on January 1, 1945 was released to the public. Katsuo Nishiyama, professor emeritus of Shiga University of Medical Science, is attempting to use the list to declare the university degree of one of Unit 731’s officers illegitimate. It seems likely the experiments which this man oversaw for his dissertation were performed on Unit 731 prisoners, rather than on animals as he had claimed. Many hope that the release of this list will be a major step towards Japan openly condemning its wartime atrocities.
For more information about Unit 731, please check out some of the sources used to write this article. Additionally, Pacific Atrocities Education has produced a book about Unit 731. You can view it here: http://www.pacificatrocities.org/unit-731-ebook.html
Brennan, David. “Identities of Japanese War Crimes Unit That Killed POWs Released.” Newsweek, 17 Apr. 2018, www.newsweek.com/identities-japanese-war-crimes-unit-killed-pows-released-889544.
Harris, Sheldon H. Factories of Death: Japanese Biological Warfare, 1932-1945 and the American Cover-Up. Routledge, 2002.
Kristof, Nicholas D. “Unmasking Horror — A Special Report.; Japan Confronting Gruesome War Atrocity.” The New York Times, The New York Times, 17 Mar. 1995, www.nytimes.com/1995/03/17/world/unmasking-horror-a-special-report-japan-confronting-gruesome-war-atrocity.html.
Park, Eun. Theodicy--Through the Case of "Unit 731". Boston University, Dec. 2003, people.bu.edu/wwildman/WeirdWildWeb/courses/thth/projects/thth_projects_2003_parkeun.htm.
Pawlowicz, Rachel, and Walter E. Grunden. “Teaching Atrocities: The Holocaust and Unit 731 in the Secondary School Curriculum.” The History Teacher, vol. 48, no. 2, Feb. 2015, pp. 271–294., www.societyforhistoryeducation.org/F15Preview.html.
Reuters, Jason Lee. “Chinese Man Looks at Figures Showing Vivisection Tests at Exhibition Hall of Historical Japanese Germ Warfare Located in South of Harbin.” Newsweek, 17 Apr. 2018, www.newsweek.com/identities-japanese-war-crimes-unit-killed-pows-released-889544.
Weeks, Linton. “Beware of Japanese Balloon Bombs.” NPR History Department, National Public Radio, 20 Jan. 2015, www.npr.org/sections/npr-history-dept/2015/01/20/375820191/beware-of-japanese-balloon-bombs.
Williams, Peter, and David Wallace. Unit 731: The Japanese Army's Secret of Secrets. London, 1989.
Unit 731 was known as a covert chemical and biological warfare research and development section of the Imperial Japanese Army that commenced lethal human experimentation during the World War 2. This program was responsible for some of the most horrific war crimes that were carried out by the Imperial Japanese Army.
Officially it was known as the Epidemic Prevention and Water Purification Department of The Kwantung Army, the site was originally set up under the command of General Shiro Ishii who was a combat medic officer at the Kwantung Army. He finished his studies in microbiology at the Kyoto Imperial University in Japan. He came up with the idea of having the facility built to keep up with the West, since they were believed to be developing their own weapons of biological warfare. The Japanese government heavily invested in the facility in order for it to function fully. General Shiro Ishii’s career started accelerating in 1932 after he was chosen to be the head of the biological warfare division where his mission was to perform covert experiments on live subjects. The location was later than moved to Pingfang and General Ishii was again appointed as the director.
Masaji Kitano was a commanding officer of Unit 731. He graduated as a medical doctor at Tokyo Imperial University. He joined the army as an army surgeon with the rank of a lieutenant. Right before the full blown Sino-Japanese War, he taught microbiology at the Manchu School of Medicine in Manchuria. Manchuria had been a puppet state of Japan’s since 1931. Read more here: http://www.pacificatrocities.org/blog/marutas-in-manchuria-imperial-japanese-biological-warfare-1931-1945
By 1942, he was made second in command of Unit 731. He was known to be the chief funeral commissioner of Shiro Ishii.
After the Japanese surrendered in August 1945, he ended up being detained in a POW camp in Shanghai. Due to a deal made with the Allied, he was released in exchange for research material of biological warfare. He was later repatriated to Japan in January 1946 and became the chief director of Green Cross, a Japanese Pharmaceutical company.
Another member of the Unit 731 was Yoshimura Hisato, who was a physiologist. Before his career in Unit 731 in 1938, he was a lecturer at Kyoto Imperial University Faculty of Medicine. He was employed by the Imperial Japanese Army as an Army Engineer, which was a researcher who was treated like an officer but not a professional military serviceperson. At Unit 731, he took a great interest in hypothermia. Taking into consideration Maruta’s study in limbs, Hisato made his prisoners submerge their limbs in a tub of water that was filled with ice and then had them hold until their leg or arm had frozen solid and a coat of ice formed in their skin. An eyewitness stated that the limb sounded like wood when they were struck with a cane. In addition the physiologist also tried different methods for rapid rewarming of the frozen appendages by dousing them in hot water, holding them close to an open fire source or even leaving the subjects all night in order for him to see how long it would take for an individual’s own blood to thaw out.
After the war was over, he was able to obtain war crime immunity, and he became the president of Kyoto Prefectural University of Medicine.
In addition, Yasuji Kaneko is also one of the alleged members of the Unit 731 as ho testimony of the crimes committed have appeared in the 2001 film known as Japanese Devils and 2007 film Iris Chang: The Rape of Nanking. He started testifying at the age of 76 in 1996 about his activities in Nanjing Massacre as well as Unit 731. As an ex-soldier of the Imperial Japanese Army, not only did he spread cholera into the water system in Linqing in 1943. He had also claimed to raped many women during the war as he could not afford comfort woman as a lower ranking soldier.
Yoshio Shinozuka was a teenager when he joined Unit 731 under the impression to provide safe drinking water to other soldiers. His day to day duty included raising fleas infected with plague on rats as well as vivisections.
There were many victims from Unit 731, but many of the soldiers were able to be freed in exchange for their knowledge of human experimentation. Many of them lived prosperous lives after the war. Although they gained a lot of science knowledge, their ways of violating human rights were mostly forgiven in the name of science.
Unit 731 of the Japanese Army conducted some of the most heinous experiments in the human history on POWs during the World War II. Unit 731 had eight divisions: Division 1- Bacteriological research; Division 2- Warfare Research and field experiments; Division 3- Water Filter Production; Division 4- Bacteria Mass production and Storage; Division 5- Educational Division; Division 6- Supplies Division; Division 7- General Affairs; Division 8- Clinical Diagnosis.
The leader of this unit was a 6-feet tall man known as Shiro Ishii. Born in Japan, Shiro was a bright young man who studied at the Kyoto Imperial University. There, he got to study preventive medicine, pathology, serology and bacteriology. In 1922 after completion of his studies at Kyoto Imperial University, he was sent to Kyushu where they were battling a contagious disease which was aggressive and causing deaths of many people including soldiers.
Shiro studied how he could effectively filter the contaminated water. He was able to successfully do it, much to the acclaim of his colleagues. To prove his filters worked to the Emperor of Japan, he demonstrated how his device worked by filtering his own urine and drinking it. In 1928, Shiro Ishii traveled extensively in various countries learning from their clinics and laboratories. After two years of travel, he returned to Japan. Due to his close association with influential and prominent officials, he was able to secure funding for his projects which he believed would propel Japan to the world leadership.
Shiro Ishii proposed a research unit to study biological and chemical weapons. He argued that the Western powers were carrying out similar programs. He got support from Colonel Chikahiko Koizumi who was the army’s Surgeon General (later become Japanese Health Minister) and had secretly joined a poison gas research committee during World War I.
Shiro Ishii was given the command of Unit 731 in 1932.
The project Unit 731 aka Epidemic Prevention and Water Supply Unit of the Kwantung Army, was initially established in Harbin. This was later to be blown up by prisoners and they had to look for a new location. Due to the kind of experiments being conducted, secrecy was a priority. Manchuria was a perfect hideout place. Manchuria was forcefully taken from the Chinese through Japanese invasion. It was about 200,000 square kilometers. In Manchuria, the research facility was set up in Pingfan and occupied three square kilometers. The buildings were strategically built to hide any suspicion and were further shielded by high walls and high voltage wires.
Later on from 1937 after Japanese expansion to China, other such facilities were set up in various Chinese cities such as Hsinking, Guangzhou, Beijing, and Nanjing.
The opportunity to work at the Unit 731 facilities was highly appealing to doctors and scientists as they the chance to experiment on human subjects and had financial aid from the army. To work here required high-level secrecy and members of the unit had to be transported in covered cargo trucks whose registration numbers were often changed to conceal identity. Some staff knew what was going on while others did not know of the “death blocks” where prisoners would pass through never to return. By 1939, Ishii’s network comprised of over 10,000 personnels conducting research at Unit 731.
by Danielle Dybbro
In a previous blog post I wrote about Unit 731, but the facility in Harbin was not the only Imperial Japanese facility used for biological warfare research.
General Shiro Ishii was the head of the Imperial Japanese biological warfare research program. Ishii made extensive visits to Europe in order to tour military hospitals during the mid 1920s, but the main reason for his European tour was to investigate biological warfare research. Ishii studied the research that was developed during World War I, which later heavily influenced his creation of Unit 731. Additionally, on his world tour, some of the countries he visited were secretly researching biological warfare, and a Military Attaché in the Japanese Embassy in Washington D.C. “said that he heard that Ishii had studied bacteriological warfare at the Massachusetts Institute of Technology in Boston.” Upon his return to Japan in 1930, he managed to convince the Japanese State Department of Military Affairs to develop a biological weapons program.
The invasion of Manchuria in 1931 by the Japanese was the golden opportunity that General Ishii had been waiting for. The wide expanses of uninhabited land served as the perfect arena for conducting biological warfare research, as the small island nation of Japan had severely limited research potential because of the issues of space and safety. By 1933 Ishii had established facilities in Manchuria for conducting both defensive and offensive biological warfare research. Defensive research involved the production of vaccines and offensive research was the main focus of the notorious Unit 731 for the purpose of developing diseases for use as weapons, including plague, glanders, anthrax, and typhus. World War II began in 1939 for the Western world, but by this time there were an estimated 18 other biological warfare facilities scattered throughout the Japanese empire, from Manchuria in the north to Indonesia in the south.
In the use of human subjects, researchers would refer to the subjects as ‘marutas’ which translated to ‘wooden logs.’ By dehumanizing the Chinese, Russian, Mongolian, and Communists that were rounded up by the Japanese secret police, the Kempeitai, researchers could justify the harsh treatment of marutas in their experiments. In a testimony, Yoshio Shinuzaka confirmed this practice and said that, “We called the victims ‘logs’… We didn't want to think of them as people. We didn't want to admit that we were taking lives. So we convinced ourselves that what we were doing was like cutting down a tree. When you see someone in that state, you just can't move. Your mind goes blank. The fear is overwhelming.”
Evidence of biological attacks in China are recorded in official records of a number of Japanese military officers, including field tests in Chinese villages leading to outbreaks of cholera and the plague. At Unit 731, bombs with fleas infected with the plague, shrapnel carrying anthrax, and planes spraying other diseases were tested on prisoners. Prisoners would be tied to stakes and the bombs would be dropped at varying distances and their bodies were monitored for reactions, which often involved cutting subjects open without anesthetic. After death, their organs would be preserved for further study.
South of Harbin, where Unit 731 was located, was the city of Changchun, which was chosen as the capital for the Manchurian puppet state. In 1936 the Anti-Epizootic Protection of Horses Unit was created in Changchun, which later became known as Unit 100. Unit 100 was not run by Ishii, but by Major Yujiro, a veterinarian who sometimes cooperated with Ishii in joint research. This unit specialized in the prevention of animal diseases, but also researched plant and animal biological warfare akin to Unit 731’s activities. The unit’s focus was on sabotage operations, with research conducted for the cultivation of crop viruses and livestock diseases. Both people and animals were subjected to experimentation, and a number of recorded testimonies from former workers and medical students describe seeing dead bodies being wheeled away from operating rooms and animals being poisoned with contaminated crops. In Soviet-sponsored war trials, a former Unit 100 worker confirmed that he had “taken part in these inhuman experiments on living people, in bacteriological sabotage and in the preparations for bacteriological warfare against the Soviet Union,” and other admissions of guilt are found throughout the trial transcript.
According to some scholarship, the United States government struck a plea bargain with General Ishii in exchange for all the medical research acquired from the experiments conducted at Unit 731. In a letter written in 1998, the Director of the Department of Justice’s Office of Special Investigations in Los Angeles confirmed that the exchange occurred: “Two of these [formerly classified] reports [about biological warfare data collected by the Japanese and the arrangement made between the United States and Lieutenant General Shiro Ishii, the Commander of the Unit 731], dated November 17, 1981 and May 5, 1982, confirm that Ishii and his colleagues received immunity from prosecution and that, in exchange, they provided a great deal of information to U.S. authorities.” In contrast, in memo dated from 1995 from the Department of the Army, Edward Drea, then the Chief of the Research and Analysis Division of Military History, claims that “there is no primary source material guaranteeing General Ishii immunity from prosecution. He was not tried as a war criminal apparently in order to conceal from the Soviet Union the extent of the information he provided the United States about biological warfare. Even that interpretation, however, rests on very fragmentary evidence.”
However, in 1995 in another primary government source, an internal memo claims that with the emergence of the Cold War, the Americans felt that they could not entrust the biological warfare information amassed by the Japanese to the Soviets. In order to keep the research from falling into Soviet hands, the documents handed over to the United States in 1945 were classified and thus were not able to be used as evidence in the Tokyo War Crimes Trials. Despite this cover up, the Soviet Union tried twelve of them in 1949 in the Khabarovsk Trials, which are available to read online through Google books.
Unfortunately, the United States “dismissed the verdicts [in the Khabarovsk trials] with the evidence as another in a series of long-running Stalinist show trials.” Additionally, though 12 Japanese officers involved with Unit 731 were tried in Khabarovsk, the convicts received prison sentences ranging from 2-25 years and most were freed in the 1950s. This is in stark contrast to the Nuremburg and Tokyo war crime trials, which resulted in German and Japanese officials being hanged or sentenced to life in prison.
Scholarship on Japan’s biological warfare program has been increasing since the 1980s with admissions of guilt by former Unit 731 workers and the discovery of a cache of forgotten military records in a Tokyo bookstore in 1984, but the issue is that the evidence is scattered and often fragmentary in nature. Historians must continue to piece together the narrative and bring to light a fuller picture of Imperial Japan’s biological warfare research that began well before the outbreak of World War II.
Cunliffe, William H. “Nazi War Crimes and Japanese Imperial Government Records: Select Documents on Japanese War Crimes and Japanese Biological Warfare, 1934-2006.” Interagency Working Group.
Drea, Edward; Bradsher, Greg; Hanyok, Robert; Lide, James; Petersen, Michael, & Daqing Yang. Researching Japanese War Crimes: Introductory Essays. Washington, D.C.: Nazi War Crimes and Japanese Imperial Government Records Interagency Working Group, 2006.
Harris, Sheldon. Factories of Death: Japanese Biological Warfare, 1932-45, and the American Cover-up. New York: Routledge Press, 1994.
“Japanese Biological Warfare Experiments in World War II,” NSC Contingency Press Guidance. U.S. Internal Memo, August 16, 1995.
Letter, December 17, 1998. Headed “Re: U.S. Non-prosecution of Japanese War Criminals,” sent to the associate dean of the Simon Wiesenthal Center, Los Angeles. Quoted in Reynolds, Gary. “U.S. Prisoners of War and Civilian American Citizens Captured and Interned by Japan in World War II: The Issue of Compensation.” Congressional Research Service Report for Congress, The Library of Congress. Updated 2002. 22.
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by Danielle Dybbro
The systematic medical experimentation of Chinese, Korean, Mongolian, and Allied prisoners during World War II was conducted by the Japanese military with the operation’s headquarters based in Harbin, Manchuria. Unit 731, also known as the Epidemic Prevention and Water Supply Department, was responsible for the deaths of at least 3000 people in the Manchurian headquarters from 1939-1945 and the experimentation of at least another 250,000. Prisoners were victims of such procedures such as live vivisection, frostbite, and disease experiments, all in the name of furthering Japanese medical, military, and biological warfare research.
Historians estimate that at least half a million people were killed as a direct or indirect result of the biological warfare field tests throughout China, which included airplanes dropping ceramic bombs filled with plague-infested fleas, anthrax contaminating water supplies, and lacing food with other infectious diseases. This biological warfare research was even considered as a tool to attack the United States: the military plan codenamed Cherry Blossoms at Night was in the works, which would have involved kamikaze pilots infesting California with the plague.
Unit 731 was just one of many Epidemic Prevention Departments, with at least 5 other permanent facilities in China, Japan, and Singapore, and at least 18 others throughout the Japanese Empire. However, In August 1945, Japan surrendered to the Allies and Unit 731’s leader, General Shiro Ishii, ordered his more than 10,000 workers to bury the evidence by destroying the facilities, killing and burying the remaining prisoners, releasing all disease-infected animals, and taking their secrets to the grave.
The United States granted General Ishii and a number of other prominent Unit 731 workers immunity from war crime investigations in exchange for the medical research they accumulated from their experiments. The Soviet-U.S. rivalry was soon to turn into the Cold War, and the U.S. wanted to get ahead of the USSR in biological warfare research. The U.S. did not want the publicity of an international war crime trial, which would leak any of the secret and valuable research to the Soviets that the Japanese had accumulated at the high cost of hundreds of thousands of human lives. As a result of this war crime immunity, a number of Unit 731 officials were able to become prominent members of society, including professors at medical schools, the director of Japan’s largest pharmaceutical company, the president of Japan’s Medical Association, and the head of the Japanese Olympic Committee.
Former members of Unit 731, including medical assistants, nurses, and doctors, have come forward and admitted to following the orders to perform experiments on prisoners and to cover up the evidence at the end of the war. However, to this day, the Japanese government has not taken responsibility for the nearly 1 million deaths that Unit 731 and its biological warfare division is estimated to have caused. Neither have any lawsuits filed by Chinese families affected by Unit 731’s research been answered by the Japanese government.
731: Two Versions of Hell. Film produced by James T. Hong. 2007.
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