By Li Chen, People’s Daily
A recently released investigative documentary by Singapore’s Channel NewsAsia, Inside Unit 731: Japan’s Secret Human Experiments, has once again brought to light a dark chapter of history that Japan’s right-wing forces have sought to obscure for decades.
The film systematically documents the crimes against humanity committed by Unit 731 of the Japanese invading forces during the Chinese People’s War of Resistance Against Japanese Aggression, while also revealing how perpetrators of Japan’s biological warfare program escaped justice amid Cold War geopolitical calculations.
The production team traveled to Harbin and Anda in northeast China’s Heilongjiang province, Quzhou in east China’s Zhejiang province, and other locations, visiting the former headquarters of Unit 731, areas devastated by biological warfare, and former Allied prisoner-of-war camps.
The filmmakers interviewed Hideo Shimizu, the only surviving former member of Unit 731 willing to testify publicly; Chinese biological warfare survivor Zhang Rongmei; and descendants of former Allied prisoners of war.
Drawing on declassified military archives from multiple countries, alongside original Japanese military medical records, the documentary pieces together a comprehensive body of evidence. Presented with restraint yet considerable emotional force, it delivers a compelling account firmly grounded in historical documentation.
The documentary reaffirms two historical facts supported by extensive evidence.
First, under the guise of biological weapons research, Unit 731 carried out inhumane experiments, including vivisection, pathogen inoculation, and cross-species blood transfusions, on prisoners and civilians, committing crimes against humanity that violated the most basic principles of human civilization.
Second, after World War II, the United States, driven by Cold War strategic considerations, secretly granted immunity to Japanese biological warfare personnel in exchange for the data obtained through these human experiments, allowing many war criminals to evade legal accountability.
That secret deal remains one of the most troubling episodes in the history of international justice. It also created conditions that later enabled historical revisionism to gain traction in Japan.
As many viewers commented after watching the documentary, remembering history is essential for building the future. Crimes against humanity must never be minimized, and historical responsibility must never be allowed to fade from view.
As the largest and most notorious biological warfare unit operated by the Japanese military during World War II, Unit 731 committed atrocities that extended far beyond China’s borders.
Modeled on Unit 731, the Japanese military established the Oka 9420 unit in Singapore and used it as a base to expand a network of related facilities across Southeast Asia. Large numbers of innocent civilians were subjected to brutal experimentation.
Japanese forces also deployed biological weapons on battlefields and throughout occupied territories, triggering outbreaks of plague, cholera, anthrax, and other deadly infectious diseases. These outbreaks claimed hundreds of thousands of civilian lives and left lasting scars across affected countries.
Yet, despite the overwhelming historical evidence, some right-wing politicians in Japan have repeatedly attempted in recent years to whitewash these crimes. They have portrayed the notorious Unit 731 as merely “a public health research institution,” promoted historical revisionism, and sought to overturn the established verdict on Japan’s wartime aggression. Such efforts undermine the foundations of regional peace and the principles of international justice.
This year marks the 80th anniversary of the opening of the Tokyo Trials. Against this backdrop, the decision by a mainstream Singaporean media organization to investigate Unit 731 and present documented historical facts carries particular contemporary significance.
The documentary itself represents a collective effort by those committed to defending historical truth and justice. It seeks to preserve historical memory, pursue historical accountability, awaken public conscience, and guard against the recurrence of such tragedies. Attempts by Japan’s right-wing forces to bury or erase this dark chapter of history are destined to fail. The international community will not allow it.
In recent years, ever more evidence documenting the crimes of Japanese militarism has continued to emerge.
The Exhibition Hall of Evidence of Crimes Committed by Unit 731 of the Japanese Imperial Army has released original Japanese experimental reports. Japan’s Kyodo News has disclosed a wartime Japanese Army report from 1940 that documents cross-species blood transfusion experiments. Extensive evidence of Japan’s biological warfare crimes was also preserved during the 1949 Khabarovsk Trial.
Taken together, declassified archives, preserved historical sites, and the testimony of survivors and witnesses constitute an overwhelming body of evidence that leaves no room for historical denial, exposing the false narratives promoted by Japan’s right-wing revisionists.
The crimes committed by Unit 731 are not only a source of profound suffering for the peoples who fell victim to Japanese aggression; they also stand as a warning to all humanity about the horrors of war.
The international community should continue to urge Japan to thoroughly eliminate the lingering influence of militarism, to confront its history of aggression honestly, and to engage in profound reflection. Only by doing so can the postwar international order be safeguarded, the hard-won peace of today be preserved, and the tragedies of war never be repeated.
