The Nazi atrocities of World War II are well documented – rightly so given the horrors they perpetuated and the scale at which they managed to commit their crimes.  However, the level of the Nazi crimes often overshadow other atrocities that occurred throughout the war, such as those of Japanese Unit 731, but that wasn’t the only thing keeping Unit 731 out of the mainstream.  More on that later.

Ishii Shiro, head of Unit 731Ishii Shiro, head of Unit 731

Led by Ishii Shiro – who held different ranks throughout the Unit’s existence but finished the war as a Lieutenant General – Unit 731’s primary facility was located in occupied northeast China in a Manchurian town called Harbin, chosen because it was fairly isolated and could be operated largely in secret.  At its peak, the facility is estimated to be similar in size to Auschwitz and consisted of workers dormitories, a prison, laboratories, an autopsy and dissection building, and other administrative buildings.  Also prominent at the facility were three large furnaces, which were used to cremate prisoners who were no longer of any scientific use.  “Scientific” is a key distinction here.

Where Nazi atrocities typically stemmed from a sense of racial superiority over their victims, Unit 731 operated on a scientific basis.  Experiments were carried out on live subjects for the purpose of observing the effects of various diseases, biological and chemical agents, weapons, and environmental conditions.  The goal of all of this was to determine the effect these factors had on the human body so they could more effectively treat Japanese soldiers.  The experiments included but were not limited to:

  • Freezing temperatures: subjects were exposed to freezing temperatures until limbs were frozen solid then were treated for frostbite in various ways;
  • Bombs: subjects were tied up at varying distances from a bomb, which was detonated in order to determine the effects of that particular bomb at specific ranges;
  • Disease: researchers used plague-infested fleas to infect prisoners and observe the rate at which symptoms became apparent.  The end goal here was to utilize the plague in bombs which were to be deployed against enemy cities and military personnel;
  • Biological and chemical agents: anthrax, tetanus, cholera;
  • Vivisection: once a subject had been exposed to any of the above conditions, he or she was likely subject to dissection without anesthetic.  The purpose of cutting open live, unsedated subjects was to observe the effects of the experiment without the potential effects of anesthesia on the human body. 

As horrible as all of this was, Japanese military personnel and doctors conducted the experiments on a clinical basis.  That is, they didn’t justify this with anything except the idea of advancing science.  So if racial superiority wasn’t at the heart of their cruel experiments, who were their victims?  Whoever.  Many of the victims – referred to as “maruta” or “logs” – were taken from within China, Korea, and Mongolia and were considered to be individuals dangerous to Japanese interests.  Western prisoners of war were also used for many experiments, as were other western civilians such as Russian women and children.

A Japanese doctor works on an unknown subjectA Japanese doctor works on an unknown subject

Unit 731 operated throughout World War II and destroyed the complex at Harbin before returning to Japan.  You would think the individuals responsible for the experiments would be tracked down, tried, and convicted in a Nuremberg-like fashion, but they weren’t.  In fact, according to a 1995  New York Times article, many of them went on to hold positions of significance such as Governor of Tokyo, President of the Japan Medical Association, and the head of the Japan Olympic Committee.  How is that possible?  Their data.

The American government was so interested in the results of these human experiments that even Ishii Shiro was allowed to live out the rest of his life peacefully in Japan in return for his data.  None of the Japanese scientists were prosecuted, and what ensued was one of the greatest cover-ups of the war, lasting until 1984 when the personal diary of one of Unit 731’s officers ended up at a Tokyo bookshop, and was discovered by chance by a medical student.  The diary detailed tetanus experiments and their results, and corroborated the 40 year old rumors of what happened in Harbin.  Not to defend the cover-up, but in the context of the Cold War prosecuting such crimes would have made all data available to the international community including the Soviet Union – an undesirable outcome for the United States and its allies for obvious reasons. 

Much of what occurred in Harbin will never be known, as the facility was destroyed and the events have been shrouded in secrecy.  However, a handful of survivors’ accounts as well as those of Japanese military officials and scientists have given us a glimpse into the horrors that occurred at the hands of Unit 731.