The Nazis were not the only nation to build death camps in the period leading up to World War II. The Japanese, too, had their concentration camps. The object was not, as with the Germans, the extermination of a people, but instead was to use incarcerated common criminals and prisoners of war as guinea pigs in biological and, to a lesser extent, chemical warfare experiments.

The rationale was simple. The fanatical, right-wing militarists who dominated Japanese society from the late 1920s to the end of World War II believed that in order to achieve their goal of Japanese domination of East Asia, they would have to rely upon exotic weapons of war such as pathogenic and chemical arms. That was horrible enough. But those who originated the program did not believe that these weapons could simply be developed in laboratories and let loose against enemies on the battlefield. They had to be tried out on human subjects.

And so a vast network of death factories was constructed that, by the time World War II had begun, stretched from the remote steppes of Inner Mongolia to Singapore, and from Bangkok to Manila. The center of this empire of death was Ping Fan, a suburb of the city of Harbin in north China, where the architect of Japan’s chemical and biological warfare program, Lt. Gen. Shiro Ishii, had his headquarters.

Each factory employed at least two thousand people, including (apart from the ordinary soldiers used to guard the facilities) some twenty thousand physicians, microbiologists, veterinarians, zoologists, and plant biologists. At a conservative estimate, their diabolical research project of testing prospective pathogens and biological weapons on the camps’ inmates involved between twelve and fifteen thousand men, women, and children.

Tens of thousands of others were killed in field tests that consisted of distributing food tainted with deadly pathogens; lacing water wells, streams, and reservoirs with other pathogens; creating cholera epidemics by injecting cholera into the veins of unsuspecting peasants, who were told they were being inoculated against the disease; and spraying or dropping various biological weapons on villages, towns, and cities from the air.

With the exception of few lesser participants, who were brought before
a show trial by the Soviet authorities, most of the architects of Japan’s biological warfare programs were never prosecuted for their crimes. The reason for this was that after the U.S. occupation of Japan, American scientists eager to acquire the experimental data garnered from these biological experiments argued successfully that their Japanese colleagues had gained invaluable insights into how the human body reacted to certain pathogens—information that would greatly assist American biological weapons programs. The result was that the U.S. occupation authorities colluded in a cover-up of what had taken place.

The use of “bacteriological methods of warfare” has been banned under international law since the 1925 Geneva Protocol on chemical and biological weapons, which was a response to the horrors of poison gas as employed in World War I. In the so-called medical case at the Nuremberg War Crimes Trials two decades later, the defendants were charged with conducting medical and biological experiments on thousands of German and non-German subjects. The tribunal ruled that whatever right Germany had to experiment on German nationals who were prisoners, that right “may not be extended… to permit the practice upon nationals of other countries who… are subjected to experiments without their consent and under the most brutal and senseless conditions… To the extent that these experiments did not constitute war crimes, they constituted crimes against humanity.”

These statutes alone should have made prosecutions of the architects of the Japanese biological warfare program almost mandatory. But they had everything to do with the Cold War and almost nothing to do with the state of international humanitarian law. That said, subsequent laws have only strengthened the prohibitions against the kinds of grave breaches of which the Japanese were guilty. Protocol I of the 1977 Additional Protocols to the Geneva Conventions explicitly forbids “medical and scientific experiments” even with the consent of the subject. And in the arms control field, the 1972 Biological Weapons Convention forbids “develop[ing]… microbial or biological agents or toxins [and] equipment” designed to use or deliver “such agents or toxins for hostile purposes or in an armed conflict.”

But leaving aside prosecutions, the truth is hard enough to come by. Until the 1980s, the Japanese government denied the crimes committed by its doctors and scientists had even taken place. When the overwhelming weight of the evidence forced it to concede something had indeed occurred, the Japanese authorities insisted the program had been the work of renegade militarists. The government neither apologized nor offered compensation to those still alive who had been exposed to the germ warfare experiments, or to the families and heirs of those who had not survived them.

(See biological weapons; chemical weapons; medical experiments on POWs.)