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The ruins of a boiler building on the site of the bioweapon facility of Unit 731.

Because In a War, You Have to Win

The events of World War II may show humanity at its lowest point. Clashing political ideologies and the ensuing worldwide combat produced a nearly unprecedented level of bloodshed and destruction.

Although the Holocaust showed the extreme nature of the war and the horrifying extent to which a nation could be driven, Japan’s Unit 731 facilities, an Auschwitz equivalent, held their own horrors in human experimentation. The following details are just some of the experiments that were performed during the unit’s existence from 1936 to 1945.

Most of us heard about the horrible experiments on humans of the Nazis done by doctor Mengele. But the Nazis weren’t alone in conducting cruel experiments on humans. One of the lesser known atrocities of the 20th century were committed by the Imperial Japanese Army’s Unit 731. Some of the details of this unit’s activities are still uncovered.

During World War II, the Japanese maintained a biological warfare lab known as Unit 731 in Pingfang, China. There the Imperial Japanese Army, under the direction of Surgeon General Shiro Ishii, conducted forced and lethal human experimentation on war prisoners that were even more barbaric than the tortures dreamed up by the Germans.

While details of much of the experimentation were destroyed by the Japanese as the war was coming to an end, it is unknown exactly how many thousands of men, women and children perished, usually from terrible and painful deaths as the medical people in the unit carved up their bodies without anesthesia while they were still alive. The prisoners were injected with various bacteria and diseases.

Torture techniques conjured up in medieval times, especially the gruesome methods employed during the Crusades, took a giant leap forward thanks to Dr Shiro Ishii’s diabolical imagination. The human suffering he was responsible for remains unimaginable and incomprehensible. He is infamous for being the director of a biological warfare research and testing program of the Imperial Japanese Army that existed from 1937 to 1945 during the Second Sino-Japanese War and World War II.

Like experiments at Auschwitz and other Nazi concentration camps, Unit 731 doctors and researchers studied the potential survival of soldiers on the battlefield. But instead of using Japanese soldiers for these experiments, Unit 731 used Allied POWs as well as Chinese and Russian civilians.

One such war-influenced experiment was in various dismemberments, particularly limb amputations, to study the effects of blood loss. Other forms of dismemberment were purely experimental and not combat-related. For example, some amputated limbs were reattached to other sides of the body. Other times, limbs were frozen and amputated until only the victim’s head and torso remained.

Because of the Unit’s secret nature, there is no known complete list of the experiments that were undertaken by Unit 731.

For 40 years, the horrific activities of “Unit 731” remained one the most closely guarded secrets of World War II. It was not until 1984 that Japan acknowledged what it had long denied – vile experiments on humans conducted by the unit in preparation for germ warfare.

Some of the more horrific experiments included vivisection without anesthesia and pressure chambers to see how much a human could take before his eyes popped out. Unit 731 was set up in 1938 in Japanese-occupied China with the aim of developing biological weapons. It also operated a secret research and experimental school in Shinjuku, central Tokyo. Its head was Lieutenant Shiro Ishii. The unit was supported by Japanese universities and medical schools which supplied doctors and research staff.

Unit 731 and Unit 100 were the two biological warfare research centres set up in spite of the Geneva Protocol of 1925 banning biological and chemical warfare.

Led by Lieutenant-General Ishii Shiro, 3,000 Japanese researchers working at Unit 731’s headquarters in Harbin infected live human beings with diseases such as the plague and anthrax and then eviscerated them without anesthesia to see how the diseases infected human organs.

Because of the Unit’s secret nature, there is no complete list of the experiments that were undertaken by Unit 731.

The researchers performed invasive surgery, removing organs from living patients to study the effects of disease on the human body. Limbs were amputated so doctors could study blood loss. Sometimes limbs were re-attached to opposite sides of the body. Or limbs were frozen and amputated, or thawed to study the effects of untreated gangrene.

Some prisoners had their stomachs surgically removed and the esophagus reattached to the intestines. Parts of brain, lungs, liver and other organs were removed in experiments to determine the effects on patients.

The prisoners were injected with a variety of diseases, including syphilis and gonorrhea and then studied. They were subjected to plague fleas, cholera, anthrax, various bio-warfare agents, forced to endure frostbite, deprived of food and water, injected with animal blood, given lethal doses of X-rays, injected with sea water, subjected to chemical weapons and burned and buried alive.

The results of much of the testing resulted in deadly biological weapons that the Japanese used in the war. For example, bubonic plague-infested fleas, bred in Unit 731 and Unit 1644, were spread upon Chinese cities by low-flying aircraft. Thousands of people perished.

Realizing he would be prosecuted for war crimes, Dr. Shiro Ishii faked his own death and went into hiding to evade justice. He was found in 1946 and turned over to American Occupation Forces for interrogation. After his capture, Dr. Ishii offered to reveal details of the experiments conducted at Unit 731 in exchange for immunity from all of the war crimes he committed. The US agreed to the plea bargain, which also included immunity for top-level members of Ishii’s medical research team. In addition to the promise of not being prosecuted for war crimes, these researchers were enticed with money and other gifts from the US to share what was learned at Unit 731.

He is a cheerful old farmer who jokes as he serves rice cakes made by his wife, and then he switches easily to explaining what it is like to cut open a 30-year-old man who is tied naked to a bed and dissect him alive, without anesthetic.

“The fellow knew that it was over for him, and so he didn’t struggle when they led him into the room and tied him down,” recalled the then 72-year-old farmer, he was at that time a medical assistant in a Japanese Army unit in China in World War II. “But when I picked up the scalpel, that’s when he began screaming.

“I cut him open from the chest to the stomach, and he screamed terribly, and his face was all twisted in agony. He made this unimaginable sound, he was screaming so horribly. But then finally he stopped. This was all in a day’s work for the surgeons, but it really left an impression on me because it was my first time.”

Finally the old man, who insisted on anonymity, explained the reason for the vivisection. The Chinese prisoner had been deliberately infected with the plague as part of a research project — to develop plague bombs for use in World War II. After infecting him, the researchers decided to cut him open to see what the disease does to a man’s inside. No anesthetic was used, he said, out of concern that it might have an effect on the results.

That research program was one of the great secrets of Japan during and after World War II: a vast project to develop weapons of biological warfare, including plague, anthrax, cholera and a dozen other pathogens. Unit 731 of the Japanese Imperial Army conducted research by experimenting on humans and by “field testing” plague bombs by dropping them on Chinese cities to see whether they could start plague outbreaks. They could.

Since the Japanese army used poison gas during the war, one of the Unit 731’s mission was to develop a more potent poison gas, thus prisoners were subjected to poisoning. In 1984, a graduate student at Keio Medical University in Tokyo found records of human experiments in a bookstore. The pages described the effects of massive dosages of tetanus vaccine. There were tables describing the length of time it took victims to die and recorded the muscle spasms in their bodies.

Unit 731 was a huge facility with over 150 buildings covering six square kilometers. The complex contained factories and cauldrons capable of producing a variety of chemicals, raise fleas, biological agents and Bubonic plague bacteria.
The official name of the facility was the Epidemic Prevention and Water Purification Department, which was a cover for what was really going on inside.

The history of Unit 731 begins with one man, Shiro Ishii. Ishii was an extremely bright young man in Japan and gained entrance to Kyoto Imperial University. Something that is important to know about Ishii is that he was close to 6 feet tall. That might seem like a useless piece of information but for the Japanese (who are generally speaking not too tall) he was like a stern tower of a giant, demanding attention and respect wherever he went. In 1922 Ishii had returned to Kyoto Imperial University to further his education and knowledge of bacteriology, serology, preventive medicine, and pathology. That same year he was sent to Kyushu. There, a highly contagious disease had become extremely aggressive and claiming many lives. The disease caused a severe amount of swelling to the brain and was extremely difficult to study. Ishii approached the problem from a different direction, rather than studying the disease (he was unable to do so efficiently because the problem lay in the brain where he was unable to get to before the patients died) he studied how to prevent effective water filtration so that soldiers weren’t drinking liquid parasites. He did this well, and because of it received much acclaim from his colleagues, and it is said that he even demonstrated how his product worked in front of the Emperor of Japan himself (supposedly Ishii swore by his filtration so much that he urinated in the filter and then proceeded to drink the clean water the filter produced). In April of 1928 Ishii left Japan to travel the world for two years studying. Ishii visited clinics and laboratories in almost thirty countries. He went everywhere from Russia to America, Germany and France. He returned with information he believed would drastically alter the fate of Japan.

The research program was one of the great secrets of Japan during and after World War II. The main goal of Unit 731 was to develop weapons of biological warfare, including plague, anthrax, cholera and countless numbers of other harmful pathogens.

Because of Ishii’s strong ties with prominent officials such as: Colonel Chikahiko Koizumi ( who would soon be the Army’s Surgeon General and later on become Japanese Health Minister), Colonel Tetsuzan Nagat (who would soon become Chief of the War Ministry’s Military Affairs Bureau) and Nobuyoshi Araki the War Minister, he was able to receive funding for projects he believed would result in Japan emerging as world leader. In 1930 when Ishii returned from his trip Koizumi (who had long been pushing the idea of funding a project for chemical and biological warfare.) Koizumi, a soldier was not as respected as other militants because he was a surgeon, and surgeons at the time had no weapon they could use in war. Koizumi would use Ishii as his tool to change all of these notions the war officials had.
In 1932 Ishii began experimenting with biological warfare as a secret project for the Japanese military. When Unit 731 was constructed in 1936, Ishii directed the design of the massive compound. By 1942, after Japan and the United States were at war, he was serving as Chief of the Medical Section of the Japanese First Army. But his duties remained at Unit 731.

Over half a century after the end of the war, books, documentaries, and exhibitions are unlocking the past and helping arouse interest in Japan in the atrocities committed by some of Japan’s most distinguished doctors. No one knows how many died in the “field testing.” It is becoming evident that the Japanese officers in charge of the program hoped to use their weapons against the United States. They proposed using balloon bombs to carry disease to America, and they had a plan in the summer of 1945 to use kamikaze pilots to dump plague-infected fleas on San Diego.

The research was kept secret after the end of the war in part because the United States Army granted immunity from war crimes prosecution to the doctors in exchange for their data. Japanese and American documents show that the United States helped cover up the human experimentation. Instead of putting the ringleaders on trial, it gave them stipends.

The accounts are wrenching to read even after so much time has passed: a Russian mother and daughter left in a gas chamber, for example, as doctors peered through thick glass and timed their convulsions, watching as the woman sprawled over her child in a futile effort to save her from the gas. The Origins Ban on Weapon Entices Military

Japan’s biological weapons program was born in the 1930’s, in part because Japanese officials were impressed that germ warfare had been banned by the Geneva Convention of 1925. If it was so awful that it had to be banned under international law, the officers reasoned, it must make a great weapon.

The Japanese Army, which then occupied a large chunk of China, evicted the residents of eight villages near Harbin, in Manchuria, to make way for the headquarters of Unit 731. One advantage of China, from the Japanese point of view, was the availability of research subjects on whom germs could be tested.

To ease the conscience of those involved, the prisoners were referred to not as people or patients but as “Maruta”, or wooden logs and most were Communist sympathizers or ordinary criminals. The majority were Chinese, but many were Russians, expatriates living in China.

Some human test subjects were taken outside during the harsh winter until their limbs froze off for the doctors to experiment how best to treat frostbite.

Takeo Wano, a former medical worker in Unit 731 who now lives in the northern Japanese city of Morioka, said he once saw a six-foot-high glass jar in which a Western man was pickled in formaldehyde. The man had been cut into two pieces, vertically, and Mr. Wano guesses that he was Russian because there were many Russians then living in the area.

The Unit 731 headquarters contained many other such jars with specimens. They contained feet, heads, and internal organs, all neatly labelled. “I saw samples with labels saying ‘American,’ ‘English’ and ‘Frenchman,’ but most were Chinese, Koreans and Mongolians,” said a Unit 731 veteran who insisted on anonymity. “Those labelled as American were just body parts, like hands or feet, and some were sent in by other military units.”

There is no evidence that Americans were among the victims in the Unit 731 compound, although there have been persistent but unproven accusations that American prisoners of war in Mukden (now Shenyang) were subject to medical experimentation.

Medical researchers also locked up diseased prisoners with healthy ones; to see how readily various ailments would spread. The doctors locked others inside a pressure chamber to see how much the body can withstand before the eyes pop from their sockets.

Other terrible weapons were developed, like the defoliation bacilli bomb and other bombs, designed with porcelain shells and laden with anthrax, typhoid, dysentery, cholera and other deadly pathogens. Fleas were often used as the carriers.
The devices developed in the lab were so deadly that one accidental spill of an unleashed biological agent in Chekiang killed an estimated 1,700 Japanese civilians.

Victims were often taken to a proving ground called Anda, where they were tied to stakes and bombarded with test weapons to see how effective the new technologies were. Planes sprayed the zone with a plague culture or dropped bombs with plague-infested fleas to see how many people would die.

The Japanese armed forces were using poison gas in their battles against Chinese troops, and so some of the prisoners were used in developing more lethal gases. One former member of Unit 731 who insisted on anonymity said he was taken on a “field trip” to the proving ground to watch a poison gas experiment.

A group of prisoners were tied to stakes, and then a tank-like contraption that spewed out gas was rolled toward them, he said. But at just that moment, the wind changed and the Japanese observers had to run for their lives without seeing what happened to the victims.

The Japanese Army regularly conducted field tests to see whether biological warfare would work outside the laboratory. Planes dropped plague-infected fleas over Ningbo in eastern China and over Changde in north-central China, and plague outbreaks were later reported.

Japanese troops also dropped cholera and typhoid cultures in wells and ponds, but the results were often counterproductive. In 1942 germ warfare specialists distributed dysentery, cholera and typhoid in Zhejiang Province in China, but Japanese soldiers became ill and 1,700 died of the diseases.

Japan’s Ghiro Ishii.

Sheldon H. Harris, a historian at California State University in Northridge, estimates that more than 200,000 Chinese were killed in germ warfare field experiments. Professor Harris — author of a book on Unit 731, “Factories of Death,” also says plague-infected animals were released as the war was ending and caused outbreaks of the plague that killed at least 30,000 people in the Harbin area from 1946 through 1948.

Many of the human experiments were intended to develop new treatments for medical problems that the Japanese Army faced. Many of the experiments remain secret, but an 18-page report prepared in 1945 — and kept by a senior Japanese military officer — includes a summary of the unit’s research. The report was prepared in English for American intelligence officials, and it shows the extraordinary range of the unit’s work.

Scholars say that the research was not contrived by mad scientists, and that it was intelligently designed and carried out. The medical findings saved many Japanese lives.

For example, Unit 731 proved scientifically that the best treatment for frostbite was not rubbing the limb, which had been the traditional method, but rather immersion in water a bit warmer than 100 degrees — but never more than 122 degrees.

The cost of this scientific breakthrough was borne by those seized for medical experiments. They were taken outside in freezing weather and left with exposed arms, periodically drenched with water, until a guard decided that frostbite had set in. Testimony from a Japanese officer said this was determined after the “frozen arms, when struck with a short stick, emitted a sound resembling that which a board gives when it is struck.”

A booklet published in Japan after a major exhibition about Unit 731 shows how doctors even experimented on a three-day-old baby, measuring the temperature with a needle stuck inside the infant’s middle finger.

“Usually a hand of a three-day-old infant is clenched into a fist,” the booklet says, “but by sticking the needle in, the middle finger could be kept straight to make the experiment easier.”

The human experimentation did not take place just in Unit 731, nor was it a rogue unit acting on its own. While it is unclear whether Emperor Hirohito knew of the atrocities, his younger brother, Prince Mikasa, toured the Unit 731 headquarters in China and wrote in his memoirs that he was shown films showing how Chinese prisoners were “made to march on the plains of Manchuria for poison gas experiments on humans.”

In addition, the recollections of Dr Ken Yuasa, 78, who still practices in a clinic in Tokyo, suggest that human experimentation may have been routine even outside Unit 731. Yuasa was an army medic in China, but he says he was never in Unit 731 and never had contact with it.

Nevertheless,  Yuasa says that when he was still in medical school in Japan, the students heard that ordinary doctors who went to China were allowed to vivisect patients. And sure enough, when Yuasa arrived in Shanxi Province in north-central China in 1942, he was soon asked to attend a “practice surgery.”

Two Chinese men were brought in, stripped naked and given general anaesthetic. Then Yuasa and the others began practicing various kinds of surgery: first an appendectomy, then an amputation of an arm and finally a tracheotomy. After 90 minutes, they were finished, so they killed the patient with an injection.

Unit 731 was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army during World War II.

When Yuasa was put in charge of a clinic, he said, he periodically asked the police for a Communist to dissect, and they sent one over. The vivisection was all for practice rather than for research, and Yuasa says they were routine among Japanese doctors working in China in the war.

In addition, Yuasa — who is now deeply apologetic about what he did — said he cultivated typhoid germs in test tubes and passed them on, as he had been instructed to do, to another army unit. Someone from that unit, which also had no connection with Unit 731, later told him that the troops would use the test tubes to infect the wells of villages in Communist-held territory.

In 1944, when Japan was nearing defeat, Tokyo’s military planners seized on a remarkable way to hit back at the American heartland: they launched huge balloons that rode the prevailing winds to the continental United States. Although the American Government censored reports at the time, some 200 balloons landed in Western states, and bombs carried by the balloons killed a woman in Montana and six people in Oregon.

Half a century later, there is evidence that it could have been far worse; some Japanese generals proposed loading the balloons with weapons of biological warfare, to create epidemics of plague or anthrax in the United States. Other army units wanted to send cattle-plague virus to wipe out the American livestock industry or grain smut to wipe out the crops.

There was a fierce debate in Tokyo, and a document discovered recently suggests that at a crucial meeting in late July 1944 it was Hideki Tojo, whom the United States later hanged for war crimes who rejected the proposal to use germ warfare against the United States.

At the time of the meeting, Tojo had just been ousted as Prime Minister and chief of the General Staff, but he retained enough authority to veto the proposal. He knew by then that Japan was likely to lose the war, and he feared that biological assaults on the United States would invite retaliation with germ or chemical weapons being developed by America.

Yet the Japanese Army was apparently willing to use biological weapons against the Allies in some circumstances. When the United States prepared to attack the Pacific island of Saipan in the late spring of 1944, a submarine was sent from Japan to carry biological weapons, it is unclear what kind, to the defenders.

The submarine was sunk, Professor Tsuneishi says, and the Japanese troops had to rely on conventional weapons alone.

In the final months of the war, Japan planned to deliver a biological weapon containing the plague against San Diego, California. The attack was set for Sept. 22, 1945, but Japan surrendered just five weeks earlier.

Unit 731 embarked on its wildest scheme of all. Codenamed Cherry Blossoms at Night, the plan was to use kamikaze pilots to infest California with the plague.

Building on the site of the Harbin bioweapon facility of Unit 731.

Toshimi Mizobuchi, who was an instructor for new recruits in Unit 731, said the idea was to use 20 of the 500 new troops who arrived in Harbin in July 1945. A submarine was to take a few of them to the seas off Southern California, and then they were to fly in a plane carried on board the submarine and contaminate San Diego with plague-infected fleas. The target date was to be Sept. 22, 1945.

Ishio Obata, who now lived in Ehime prefecture, acknowledged that he had been a chief of the Cherry Blossoms at Night attack force against San Diego, but he declined to discuss details. “It is such a terrible memory that I don’t want to recall it,” he said.

Tadao Ishimaru, said he had learned only after returning to Japan that he had been a candidate for the strike force against San Diego. “I don’t want to think about Unit 731,” he said in a brief interview in 2005. “Fifty years have passed since the war. Please let me remain silent.”

It is unclear whether Cherry Blossoms at Night ever had a chance of being carried out. Japan did indeed have at least five submarines that carried two or three planes each, their wings folded against the fuselage like a bird.

But a Japanese Navy specialist said the navy would have never allowed its finest equipment to be used for an army plan like Cherry Blossoms at Night, partly because the highest priority in the summer of 1945 was to defend the main Japanese islands, not to launch attacks on the United States mainland.

If the Cherry Blossoms at Night plan was ever serious, it became irrelevant as Japan prepared to surrender in early August 1945. In the last days of the war, beginning on Aug. 9, Unit 731 used dynamite to try to destroy all evidence of its germ warfare program, scholars say.

General Douglas MacArthur.

Partly because the Americans helped cover up the biological warfare program in exchange for its data, Gen. Shiro Ishii, the head of Unit 731, was allowed to live peacefully until his death from throat cancer in 1959. Those around him in Unit 731 saw their careers flourish in the post-war period, rising to positions that included Governor of Tokyo, president of the Japan Medical Association and head of the Japan Olympic Committee.

By conventional standards, few people were crueler than the farmer who as a Unit 731 medic carved up a Chinese prisoner without anaesthetic, and who also acknowledged that he had helped poison rivers and wells. Yet his main intention in agreeing to an interview seemed to be to explain that Unit 731 was not really so brutal after all.

Asked why he had not anesthetized the prisoner before dissecting him, the farmer explained: “Vivisection should be done under normal circumstances. If we’d used anaesthesia, that might have affected the body organs and blood vessels that we were examining. So we couldn’t have used anaesthetic.”

When the topic of children came up, the farmer offered another justification: “Of course there were experiments on children. But probably their fathers were spies.”

“There’s a possibility this could happen again,” the old man said, smiling genially. “Because in a war, you have to win.”

Ironically, Japan’s Ghiro Ishii had the facilities to develop a massive and deadly bacterial war machine and promoted the idea to his superiors. But Japanese command snubbed the idea until it was too late. The planned attack on San Diego would have been among the first of its kind, but was never carried out.
When the war ended, the Japanese attempted to destroy the Unit 731 lab.

Before Japan’s surrender, the site of the experiments was completely destroyed, so that no evidence is left. Then, the remaining  prisoners were shot and employees of the unit had to swear secrecy. The mice kept in the laboratory were then released, which could have cost the lives of 30,000 people, since the mice were infected with the bubonic plague, and they spread the disease.

Few of those involved with Unit 731 have admitted their guilt. Some caught in China at the end of the war were arrested and detained, but only a handful of them were prosecuted for war crimes. In Japan, not one was brought to justice. In a secret deal, the post-war American administration gave them immunity for prosecution in return for details of their experiments. Some of the worst criminals, including Hisato Yoshimura, who was in charge of the frostbite experiments, went on to occupy key medical and other posts in public and private sectors.

In the surrender agreement, General Ishii and his staff were granted immunity from trial for war crimes in exchange for the medical information gained from the experiments. Thus many of the amazing advancements in medicine since World War II were the result of the insidious experimentation that went on among war prisoners in both Japanese and German labs.

In 1946, US General Douglas MacArthur granted all the Japanese scientists’ immunity from war crimes prosecution in exchange for the germ warfare data gathered from experiments in Harbin.

As explained in an internal War Department memorandum, dated June 23, 1947: “Since it is believed that the USSR possesses only a small portion of the technical information, and since any war-crimes action would completely reveal such data to all nations, it is felt that such publicity must be avoided in the interests of defense and security of the U.S. It is believed also that the war-crimes prosecution of Gen. Ishii and his associates would serve to stop the flow of much additional information of a technical and scientific nature.”

Gen. Ishii lived on the outskirts of Tokyo until his death in 1959. Other “graduates” of Unit 731 include the former governor of Tokyo, the former president of the Japan Medical Association, the former director of the health ministry’s preventive health research centre, the former chairman and president of Green Cross Corp. and the past heads of a number of Japanese medical schools. The man in charge of vivisections, Yoshisuke Murata, became director of the respected Kyoto University medical school, and later medical director at Kinki University.

The immunity deal granted to Dr. Ishii and members of his senior medical staff was kept secret from the public for years (with the assistance of the British government), until details of the atrocities finally appeared in the media in the 1980s. In 2001, a documentary titled Japanese Devils was released that was created from first-hand accounts of the death camp by members of Unit 731 who had been taken prisoner by the Chinese and later released.


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