Thomas Holt
Unit 731
Ever since World War I the existence of biological warfare has been a concern to all nations, which is why many were banned in the Geneva Convention. Despite this international ban, some nations, in clear disregard of human rights, have tried to develop biological weapons for illegal use. Since no other time has there been such a concentrated effort as the Japanese in World War II. The lack of public knowledge of the Japanese World War II biological warfare research group, Unit 731, in comparison to Nazi human experimentation, is an outrage especially considering it’s size, the cruelty of the experiments, and how many of the leaders of the group went on to live normal lives after the war. The sheer scale of Unit 731 cause many people to wonder why they had never heard of it.
As the Japanese acquired territory, they clearly had plans to develop biological warfare and began setting up extensive programs as early as 1931. After the Japanese occupied Manchuria in 1931 they set up a biological warfare program with laboratories in Tokyo and Harbin and a small human experimentation facility in the small village of Beiyinhe, 100 km south of Harbin (Ziegler). However, in 1934 the Japanese decided to build a much larger facility in the village of Ping Fan, 20km south of Harbin. The facility was huge with living quarters for 3,000 staff members including 300-500 doctors and scientists and had its own airport and railway (Ziegler). In 1936 the Emperor Hirohito signed a degree which formally established a biological warfare unit at Ping Fan. The unit was top-secret and was officially known as the Anti-Epidemic Water Supply and Purification Bureau but was referred to as Unit 731 (Ziegler). In addition to the facility at Ping Fan, several smaller satellite units were established in China. When the unit was set up its command was given to General Shiro Ishii, a graduate of Kyoto Imperial University who had become attracted to biological warfare after the Geneva conventions banned biological warfare (Hudson). After the war, US intelligence documents commented on Ishii saying:
The idea of bacterial warfare was solely that of Ishii. He came back from Europe in 1930 and immediately initiated steps for financing bacterial warfare, both offensive and defensive. Most microbiologists in Japan were connected in some way or another with Ishii’s work. He mobilized most of the Universities in Japan to help in research for his unit (Cunliffe)
Ishii soon began to gather his resources and massive funding from Tokyo in order to create biological weapons.
Shiro Ishii created and led a huge effort to perfect biological warfare. Speaking to his staff he declared, “A doctor’s God-given mission is to block and treat disease, but the work on which we are now to embark on is the complete opposite of those principles” (Hudson). Unit 731’s main goals were to investigate which diseases were best suited for biological attacks and to develop methods to mass-produce, store, transport and disseminate these diseases. Typhoid, cholera, dysentery, anthrax, glanders, plague, tetanus, gas gangrene and many other diseases were all considered as possible biological warfare agents (Ziegler). Over 1000 culture boxes were harvested daily for the production of such diseases (Ziegler). Methods of dissemination for biological agents investigated by the Japanese included bombs, artillery shells, spray from aircraft and sabotage. The principal effort was devoted to bomb development. Nine aircraft bombs had been developed and tested by 1940. They included bombs designed for ground contamination, production of infectious clouds and fragmentation munitions for production of casualties by wound infection (Cunliffe). Porcelain bombs were eventually determined to be the most effective due the small amount of explosives required which prevented excessive damage to the disease. In addition, the use of insects as agents for disease was developed at Ping Fan, with millions of plague-carrying fleas bred in order to be dropped on targets (Ziegler). In order to gather this data, Unit 731 had to resort to horrific means.
The sheer horror of the experiments committed by Unit 731 would have convinced anyone to try the unit’s commanders for war crimes. Since the object of Unit 731 was biological warfare, countless numbers of prisoners were the subject of human experimentation in order to test the effectiveness of diseases. The experiments were absolutely horrifying:
But the torture inflicted upon them is unimaginable: they were exposed to phosgene gas to discover the effect on their lungs, or given electrical charges which slowly roasted them. Prisoners were decapitated in order for Japanese soldiers to test the sharpness of their swords. Others had limbs amputated to study blood loss – limbs that were sometimes stitched back on the opposite sides of the body. Prisoners were exposed to extreme cold until their arms or legs were deep frozen, to test different techniques to treat frostbite. To test weapons, victims were tied to stakes to find the best range for flame-throwers, or used to test grenades and explosives positioned at different angles and distances. They were used as targets to test chemical weapons; they were bombarded with anthrax. Other victims had various parts of their brains, lungs or liver removed, or their stomach removed and their esophagus reattached to their intestines. People were locked into high-pressure chambers until their eyes popped out, or they were put into centrifuges and spun to death like a cat in a washing machine. To study the effects of untreated venereal disease, male and female “logs” were deliberately infected with syphilis. Other experiments involved hanging prisoners upside down to discover how long it took for them to choke to death, and injecting air into their arteries to test for the onset of embolisms. Some appear to have had no medical purpose except the administering of indescribable pain, such as injecting horse urine into prisoners’ kidneys (Hudson)
The Japanese called the prisoners “logs”. This slang derived from the cover story for Ping Fan during the construction period: The Chinese laborers and inhabitants of Ping Fan were told that the huge Ping Fan complex was destined to become a sawmill. Not a single “log” that entered Ping Fan survived. With no exception, all of them died in experiments or were killed thereafter. It’s estimated that 3000 to 1200 people died in Ping Fan and only about 277 of these victims have been identified (Ziegler). Chinese were not the only nationality torture in Ping Fan. In 1995 the US Department of Veteran Affairs announced in a statement, “We have conclusive evidence that unethical experiments such as dissections of live human beings were performed on captured US airmen and other American POW’s” (Cunliffe). Unit 731 soon applied the knowledge it gained from experiments into actual biological warfare.
The Japanese committed some of the deadliest biological attacks in history on Chinese villages. The Japanese had numerous plans for biological warfare such as a proposal to carry plague, anthrax and other diseases to the US west coast with balloons (Hudson). By 1940 the Japanese had perfected the method of spreading plague through fleas and began to test it on Chinese villages. On October 4 1940, a Japanese airplane dropped plague-infected fleas over Quzhou, a small town in Western Zhejiang province. A few days later, the first victims in Quzhou died, and soon the plague spread all over the region. The last human case of plaque in Quzhou and neighboring areas was reported in 1948 after 5000 people had died of plague (Ziegler). Today, the local Center of Disease Control is still monitoring the local rat population for plague and plague antibodies were detected in rats up until 1990 (Ziegler). Quzhou was not the only area attacked and plague was not the only disease used. In 1942 the Japanese used scorched earth tactics and biological agents against villages along the Zhejiang- Jiangxi in retaliation for assisting American bombers. Following the attacks many villagers got sick and died while others developed painful ulcers on their legs. Today, settlements in a region around the small city of Jinhua in central Zhejiang are still known as the “rotten leg villages”. In some, more than 5 percent of the inhabitants developed festering wounds on their legs (Ziegler). Today, residents in the province of Zhejiang have tried to receive compensation from the Japanese government for the plague attacks. Epidemiological evidence indicates that:
Bubonic plague never occurred in Quzhou before. After careful investigation it was believed that the strange visit of the enemy plane was the cause of the epidemic and the transmitting agent was rat fleas, presumably infected with plague and definitely dropped by the enemy plane. As plague is primarily a disease of rodents, the grain was probably used to attract the rats and expose them to the infected fleas mixed therein (Cunliffe).
This data, along with a diary by a high-ranking Japanese officer which contains references to the plague attacks, has been used as evidence by the group for the attacks (Ziegler). A Japanese court in 2002 declared that biological attacks had occurred in China, but rejected calls for compensation (Ziegler). Japanese courts have dismissed similar cases, including one in May 2005, on grounds that government compensation issues had been resolved by post-war treaties (China). Japan’s refusal to compensate its victims is an outrage, especially considering how Germany had similar programs during World War II but still admitted their crimes.
Unit 731 was vastly larger and horrendous in comparison to Nazi human experimentation. The human experimentation committed by Nazi doctors at concentration camps is widely known. There are few people who are not aware of the experiments committed by Dr. Josef Mengele at Auschwitz and who, upon learning of them, did not react in horror. However, the horrors of Nazi experiments begin to pale in comparison to Unit 731. It is estimated that there were about seven thousand victims of Nazi human experimentation. The experiments conducted by Mengele and others mainly involved experiments to test hypothermia, inoculations against diseases, bone-grafting, the effectiveness of mustard and phosgene gas, sterilization of “inferior races” and attempts to prove Nazi racial theories (Holocaust). As can be seen, these experiments were vastly less numerous and as horrific as the experiments committed by Unit 731. In comparison, between 3000 to 12000 people were victims of human experimentation at Unit 731, with not a single victim surviving. And the experiments conducted on those victims later led to the death of an estimated 400,000 Chinese in biological attacks (Hudson). In addition, the human experimentation conducted in Nazi concentration camps were mainly the work of individual doctors while Unit 731 was a vast, nationwide effort with large amounts of government funding. Following World War II 23 leading Nazi physicians were given their own trial during the Nuremberg Trials called the “Doctor’s Trial” and were charged with “murders, tortures, and other atrocities committed in the name of medical science” (Holocaust). Sixteen of the doctors were found guilty and seven were executed (Holocaust). Meanwhile, Dr. Mengele was forced to flee to South America after the war and lived until his death in 1979 as a wanted war criminal. Why then, were no physicians of Unit 731 ever tried for “murders, tortures, and other atrocities committed in the name of medical science”?
In what may be the most shameful act of World War II, no member of Unit 731 was ever put on trial for war crimes, by the US or Japan. In the autumn of 1945, General MacArthur, commander of the US occupation force, granted former staff members of Unit 731 immunity from prosecution for war crimes. Unit 731 was also never mentioned in the Tokyo War Crimes Tribunal (Hudson). In addition to being shielded from war crimes prosecution, the US gave these staff members money and rewards in exchange for their research data. Why all this sudden desire for data on biological warfare? The US feared the Soviets would beat them in developing biological weapons unless they had Unit 731’s research data (Kyodo). As a result of this, war criminals were allowed to walk the streets and live normal lives. Shiro Ishii went on to live a prosperous life and died of throat cancer at the age of 67. The man who succeeded Ishii as commander of Unit 731 towards the end of the war, Dr Masaji Kitano, became head of Green Cross, one of Japan’s largest pharmaceutical companies (Hudson). Other staff members went on to hold positions in the Japanese Medical Association, the Japanese Bacteriological Society, the Preventive Health Research Laboratories, National Cancer Center, National Institutes of Health and many other Japanese medical organizations (Ziegler). As a result of this Japan continues to deny Unit 731’s existence to this day.
Unlike Germany, which atoned for its war crimes, Japan has been able to deny the evidence of Unit 731. When, as now, it does admit its existence, it refuses Chinese demands for an apology and compensation on the grounds that there is no legal basis for them – since all compensation issues had been settled by a treaty with China in 1972 (Hudson)
Along with the Japanese government, most Japanese medical associations remain silent on Unit 731. In addition, most Japanese documents on Unit 731 remain classified (Ziegler). This silence from the Japanese is most likely the reason knowledge of Unit 731 is not widespread.
Unit 731 was one of the greatest war crimes of World War II and must become publically recognized as such. Everyone should know of the horrific human experiments and the testing of biological weapons on Chinese villages. Japan should be forced to acknowledge the existence of Unit 731 and compensate victims. The US must also recognize that they set war criminals free. It would be unacceptable to not do so especially considering how Nazi doctors were tried for war crimes and had their actions become common knowledge. In doing so, justice would finally be brought and the world would learn to prevent future development of biological warfare.
Works Cited
“China recalls germ warfare experiments” China Daily. 03 February 2009.
http://www.chinadaily.com.cn/english/doc/2005-05/06/content_439768.htm
Cunliffe, William H. “Select Documents on Japanese War Crimes and Japanese
Biological Warfare, 1934-2006”. The National Archives. 01 February 2009
http://www.archives.gov/iwg/japanese-war-crimes/select-documents.pdf
Hudson, Christopher. “Doctors of Depravity”. The Daily Mail. 01 February
Kyodo. “US paid for Japanese human germ warfare data”. ABC News. 01 February
“The Doctor’s Trial: The Medical Case of the Subsequent Nuremberg Proceedings”.
United States Holocaust Memorial Museum. 04 March 2009. http://www.ushmm.org/wlc/article.php?lang=en&ModuleId=10007035
Ziegler, Matthias. “Ping Fan Slideshow”. The Sunshine Project. 01 February 2009.
Johlerpow and Zale et al. 
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