Unit 731 was the principal Japanese biological
warfare research center during the Pacific War. Located at
Pingfang, Manchuria, about
twelve miles (19 km) south of Harbin,
the unit was founded in 1932 under the direction of Lieutenant
General Ishii Shiro, who was a trained medical doctor.
Ishii was also a flamboyant and eccentric inventor, who at one
invented a new water filter for the Japanese Army. Invited to
demonstrate his invention to the Emperor,
who was also trained in biology, Ishii urinated into the filter
offered the Emperor the purified liquid to drink. When the Emperor
declined, Ishii drank the liquid himself.
Ishii had concluded that, if biological weapons were
worth banning under the 1925 Geneva
must be very powerful, and he used his connections in the
government and military (particularly with Nagata Tetsuzan, the
leader of the Control Faction within the Army) to secure the
resources for secret biological
warfare experiments. A facility was constructed 60 miles (100 km)
of Harbin at Zhong Ma, near the main Manchurian rail system, and a
prison camp was built nearby.In 1935 the facility was shut down
Ishii moved Unit 731 to a larger facility at Pingfang. The new
covered an area of four square miles (13 km 2) and
had about 150 structures, built to such standards that there was
difficulty demolishing the facility as the Russians approached in
Unit 731 was organized into eight divisions. Division 1 conducted laboratory experiments into typhus, anthrax, plague, cholera, and tuberculosis using human subjects as guinea pigs. The local cover story for the facility was that it was a lumber mill, and its staff thought it hilarious to refer to their victims among themselves as maruta, "logs." The maruta numbered at least three thousand, mostly Chinese but also some Koreans, Russians, and British and American prisoners of war. Test subjects were sometimes dissected alive without anesthesia at the conclusion of experiments (Kristof 1995):
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. 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.
Division 2 was responsible for weaponization of biological agents and conducted field tests against the Chinese. Division 3 was based in Harbin and carried out production of weaponized agents. Division 4 investigated other lethal agents, while the remaining divisions carried out training and other support functions.
Some of the experiments were not directly related to
biological warfare. These included experiments that seem utterly
pointless, such as amputating a limb and reattaching it to a
part of the body or removing the stomach and reattaching the
to the intestine. Other experiments, such as the deliberate
limbs to study the effects of frostbite and development of
had real medical value, though this could never justify the use of
unwilling human test subjects.
By the time war broke out, Unit 731 had established several satellite facilities including an open-air test facility 80 miles (130 km) from Pingfang; Unit 100 at Changchun, which investigated biological agents for destroying enemy livestock; Unit 1855 at Peiping, which specialized in plague research; Unit Ei-1644 at Nanking; and Unit 8604 at Canton, which ran a rat farm and investigated water-borne agents. After war broke out in the Pacific, additional facilities were established, including Unit 9240 at Raffles Medical University at Singapore to investigate plague and malaria. Unit 731 may also have had personnel at the Japanese chemical warfare production facility at Okunoshima in the Inland Sea.
British, American, and Australian prisoners of war
at Hoten Camp near Mukden were
visited by a large group of Japanese medical officers on 13
February 1943 and given
what they were told were inoculations against typhoid. Within ten
186 prisoners were dead. Documents have surfaced indicating that
Japanese medical officers were from Unit 731, which strongly
that the "inoculations" were of live biological warfare agents
tested on the prisoners.
When the facility was overrun by the Russians
in August 1945, the fleeing
staff released plague-infected mice that may have been responsible
a plague outbreak in Harbin in 1947 that killed 30,000 persons.
However, since plague was endemic in China in 1945, this claim is
The existence of Unit 731 was almost certainly
known to the Emperor and to
General Staff. The existence of the unit also became
known to U.S.
authorities, on 27 March 1945, when four captured Japanese medical
officers revealed its existence to interrogators at Camp Tracy.
Following the Japanese surrender,
Ishii gave documents produced by the unit to the
American occupation authorities in return for immunity from
prosecution. As a result, the occupation authorities chose to
cover up the existence of the unit rather than risk having its
results become known to the Russians. As a result, none of its
commanders or scientists were tried as war criminals, a denial of
in the name of national security that most American historians
have come to view as deeply shameful.
Kristof (1995; accessed 2012-3-24)
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