It’s one of the sicker jokes of our recent history that Unit 731 is best known for the infamously noxious Chinese film, Men Behind The Sun. The violence that it portrays is – in the West, at least – more notorious than the horrors it was based upon. While the Japanese program of human experimentation differs from the Holocaust in scope and intention it’s not entirely unlike the final solution being eclipsed by the reputation of The Night Porter. This, from what I’ve read, isn’t all that accidental.
Unit 731 was established in the 1930s to conduct chemical and biological research. It was the headquarters of many other giant units, based around China, Manchuria and Singapore. Under General Shirō Ishii, a Japanese officer and scientist, its programmes largely centred on human experimentation. In gigantic labs of awful, clinical indifference prisoners were infected with disease, exposed to intense cold or chopped apart while still alive. In the midst of pain and death they were carefully studied. The sick rigor of the Japanese inquiry is borne out by just how influential their findings remain. Dr Yoshimura Hisato’s torture of frozen captives, for example, now informs our research into frostbite.
The Unit also carried out biological weapons research. Captives were infected with spores inside laboratories, and attacks were launched against Chinese villages and towns. Tainted rats and fleas were spread and it’s claimed that poisoned sweets were distributed. Their victims weren’t treated like lab rats – those tests are regulated. This was a dearth of fellow feeling.
After the war, and the odd speculative news report, Ishii was arrested by U.S. intelligence agents. Sheldon Harris writes, in his Factories of Death…
Ishii was permitted to live in style at his Tokyo residence and was considered under house arrest. He was not transported to the prison where the principal war criminals were held.
Indeed, Harris claims that the U.S. suppressed the evidence of Ishii’s guilt, leaning on Ralph Teatsworth, the United Press Association’s bureau chief.
Several investigations were launched into Unit 713 but in contrast with the coming trial of Nazi doctors they weren’t undertaken with an eye on justice. Tsuneishi Keiichi writes that …
…not one of the members of Unit 731 who returned to Japan was tried as a war criminal. Instead…unit officers were asked to provide information about their wartime research, not as evidence of war crimes, but for the purpose of scientific data gathering. In other words, they were granted immunity from prosecution in exchange for supplying their research data.
The first…two reports contained information on the unit’s bacteria bombs, but did not address the subject of human experimentation or the trial use of biological weapons. Kitano Masaji…was instructed by Lt. Gen. Arisue Seizo, the Japanese chief of intelligence, that he should not talk about “human experimentation and biological weapons trials”…In other words, until that time, these two subjects had been effectively concealed.
At the end of 1946, however, the U.S. caught wind that Russia was planning to try cases involving human experimentation and biological weapons. Two further reports were produced to deal with the claims. One, by Dr Edwin Hill and Dr Joseph Victor, discussed the information that the Unit had acquired; information that “could not [have been] obtained in our…laboratories because of scruples attached to human experimentation”. Hill hoped that the scientists he’d bought this information from “w[ould] be spared embarrassment”.
He needn’t have worried. An internal memorandum claimed “any ‘war crimes’ trial would completely reveal [their] data to all nations” and, thus, “publicity must be avoided”. In a lengthy article for The Bulletin of Atomic Scientists, Jonathan Powell revealed the fruits of some of this data…
U.S. biological warfare experts learned a lot from their Japanese counterparts. While we do not know exactly how much this information advanced the American program, we have the Fort Detrick doctors’ testimony that it was “invaluable”. And it is known that some of the biological weapons developed later were at least similar to ones that had been part of the Japanese project. Infecting feathers with spore diseases was one of Ishii’s achievements and feather bombs later became a weapon in America’s biological warfare arsenal.
While the U.S. did its bit to cover up the Unit’s crimes Japan was never going to admit its armed force’s misdeeds. Its programmes have hardly been recognised since. Some of the criminals oozed into a peaceful retirement; others became widely respected professionals. Masaji Kitano became a director for the profitable pharma company, the Green Cross. Hisato was made President of the Medical Faculty of the University of Kyoto. General Shiro Ishii died a calm, quiet death in total freedom. I’ll bet Mengele would have kicked himself if he’d known. If only he’d done more research into biological weapons he might have been immune rather than a morality tale.
There’s a decent documentary on Unit 731 on youtube (1, 2, 3, 4). I wrote on the Allies’ employment of German fascists here. Some notes on human experimentation are here, here and here.
 Eckhart, Man, Medicine, and the State (pg. 189)
 Just try googling “Studies on the Reactivity of Skin Vessels to Extreme Cold“
 Harbin and Kattoulas, Time, “Black Death“
 Michael Brockhoff, Unit 731: Nightmare in Manchuria
 Harris, Factories of Death (pg. 243)
 Tsuneishi, Z-Net, “Unit 731 and the Japanese Imperial Army’s Biological Warfare Program“
 Powell, The Bulletin of Atomic Scientists, “A Hidden Chapter in History“