Documentary works: experience, testimony, and memory

In 1950, the USSR made public the historical evidence concerning biological warfare in the Second World War for the first time through the publication of Materials on the Trial of Former Servicemen of the Japanese Army Charged with Manufacturing and Employing Bacteriological Weapons. Footnote ⁷ This publication was translated into different languages including English, Chinese, Russian, German, Japanese, and Korean. The Materials on the Trial of Former Servicemen of the Japanese Army includes indictments, confessions of the accused, witness statements, documentary evidence, and legal judgments. The historical facts of Unit 731’s human experimentation and its planning and deployment of biological warfare became known to the outside world for the first time, paving the groundwork for scholars to begin historical investigation and research.

The medical crimes committed by Unit 731 first entered the field of vision of Japanese medical historians in 1956. Only scattered written records existed at that time, and systematic academic investigation had yet to take shape. Research was still in its early stages, characterised by a lack of comprehensive knowledge. For instance, Special Forces Unit 731 published in 1956 was the first official publication written by a former Unit 731 member.Footnote ⁸ Human experimentation, biological warfare, and the Khabarovsk War Crimes Trials were presented in oral history form from the perspective of the author Akiyama Hiroshi as a personal witness.Footnote ⁹ Then, in 1957 Masao Tamura wrote in A Century of Japanese Medical History that ‘among the direct combat activities supported by Japanese physicians, the most inhumane and horrifying were undoubtedly the preparations for biological warfare… This unit produced bacteria, employed biological weapons, and conducted human experimentation’.Footnote ¹⁰ The 1967 publication, History of Science and Technology in Japan, included a section on Military Medicine, providing an initial overview of the Army Medical School’s research into biological and chemical warfare, and excerpting trial records from the Khabarovsk Trials in the Soviet Union. This work states explicitly that ‘under the guise of the Kwantung Army’s Epidemic Prevention and Water Supply Department, Shiro Ishii, Director of the Army Medical School’s Epidemic Prevention Research Laboratory, initiated the development and experimentation of biological weapons. Although all facilities were destroyed and documents burned upon Japan’s defeat, the detailed circumstances remain unclear. The trials records from the Soviet Khabarovsk Trials constitute the sole available source for understanding this general process.’Footnote ¹¹ This demonstrates that due to limitations in historical records and the silence of most individuals associated with Unit 731, the truth about the unit long remained shrouded in mystery.

In 1966, Yoshinaga Reiko published The Horror of Human Experimentation: Memoirs of a Kwantung Army Female Dependant, in which she, as a firsthand witness and dependant of a Kwantung Army member, recounted the atrocities of human experimentation.Footnote ¹² This was followed by Shimamura Takashi’s publication of Three Thousand Human Experiments in 1967.Footnote ¹³ The works of Yoshinaga and Shimamura relied mostly on the Materials on the Trial of Former Servicemen of the Japanese Army as the major reference material. These publications mainly recorded the wartime situation of Unit 731, and introduced the topics of wartime human experimentation, the biological warfare attacks in Zhegan and Changde, and historical evidence of the related Unit 100. These works contributed to raising Japanese society’s awareness of Unit 731 and of the Khabarovsk War Crimes Trials in particular. However, publications on Unit 731 in this period were reflective of the perceptual understanding of the war experience of the witnesses. As they were mainly based on oral testimonies and supplemented to a certain extent by textual materials, these publications should be categorised as documentary literature, rather than rigorous and critical academic research.

The 1967 publication, History of the University of Tokyo Faculty of Medicine: A Centennial Review recounts the faculty’s wartime experiences, including the shortening of academic programs and the establishment of affiliated medical departments. It documents particularly the US B-29 bombings of Tokyo and the atomic bombings of Hiroshima and Nagasaki, detailing the faculty’s responses to arduous wartime conditions.Footnote ¹⁴ Throughout the entire text of the Centennial History, there is no mention of the Faculty of Medicine’s active participation in the war or its aiding of the war effort, nor does it address the issues of war crimes or war responsibility. Instead, the Centennial History adopts a victim’s perspective to denounce the atrocities committed by the US military, while avoiding any mention of the Faculty’s own active involvement in the war effort. This omission perhaps reflects a broad ambivalence towards the historical role of the Faculty of Medicine in the Japanese war effort.Footnote ¹⁵

Subject transformation: from perceptual understanding to rational research

Takasugi Shingo’s The Original Sin of Japanese Medicine: Human Experimentation and Wartime Responsibility and Human Experimentation in Japan: Its Ideology and Structure, both published in 1973 were representative academic achievements of the 1970s.Footnote ¹⁶ Takasugi’s research made two main breakthroughs: first, he placed Unit 731 in the context of medical ideology, medical education, and the wartime Japanese medical system, integrating the theories and methodologies from the discipline of the social history of medicine, and analysing how science was mobilised under state power and in line with state policies under the wartime system;Footnote ¹⁷ second, from the perspective of war responsibility, he explored the ‘ideology of objectification of human beings’ in wartime Japanese medical education, defining the ‘original sin of Japanese medicine’ as ‘serving the rulers while oppressing the people who were ruled’.Footnote ¹⁸ These two works published by Takasugi can be seen as a watershed between popular reading and academic research. Before Takasugi’s publication, publications related to Unit 731 had dabbled in a certain degree of academic scholarship, but they remained at the level of combing and interpreting the evidence from the Khabarovsk War Crimes Trials. However, after Takasugi’s research publications, mainstream publications gradually increased in academic rigour, venturing into the disciplines of political history, history of science and technology, history of medicine, and ethics. Overall, works on Unit 731 were no longer relying dominantly on oral historical materials but instead focused on the integration of oral testimonies with archival materials and emphasised the excavation, examination, and analysis of historical evidence.

At the same time, a large number of veterans’ memoirs and witnesses’ oral testimonies continued to be published during this period. In 1977, Tomokatsu Matsumura published the Memoirs of the Vice Chief of Staff of the Kwantung Army in 1977, which included the section ‘Lieutenant General Ishii, the authority on biological warfare’, and documented Ishii Shiro’s wartime activities as a firsthand witness.Footnote ¹⁹ In 1979, Banseisha published in Tokyo Documents: Biological Warfare, which included new historical materials such as the ‘Membership Directory of the Seikonkai’, marking the first time that the organisation of Unit 731 and its post-war activities were made known to the public.Footnote ²⁰

Based on the publications from the 1950s to 1970s, several key characteristics emerge. First, the authors of the memoirs and documentaries were those who were directly involved in the activities of Unit 731 or who had close relationships with the members of the Unit. In contrast, the Japanese medical profession paid little attention to issues related to Unit 731, which is likely due to the fact that many doctors associated with Unit 731 still occupied important positions after the Second World War,Footnote ²¹ and they unambiguously chose to remain silent with regards to this dark past.Footnote ²² Second, most publications focused on revealing the existence and wartime activities of Unit 731 through roughly outlining the basic structure of the Unit, detailing the human experimentation and biological warfare atrocities committed by the Unit, and preliminarily analysing the internal and external causes of such inhumane behaviour. Third, those who had personal involvement in or close relationships with Unit 731 were most active in areas such as media interviews, testimony gatherings, and publishing books. Thus, many of the publications appeared in the form of documentary works and personal memoirs. Although a large number of oral testimonies, photographic evidence, drawings, and figures were cited, the investigation and use of original archival materials were not yet common. Hence, this period paved the way for scholars to enhance the scope of archival research.Footnote ²³ Fourth, the influence of publications of this period was largely confined to Japan. Academia in China, Europe, and the United States paid little attention to the issue of Unit 731 prior to the 1980s.

The excavation of textual materials: systematic study from the perspective of the history of science and technology

Building on the excavation of trial materials, oral histories, memoirs, and wartime publications, Japanese scholars such as Tsuneishi Keiichi began to turn their attention to public archives in Japan, the United States, and Russia. The Vanished Germ Warfare Unit Footnote ²⁹ and Organized Crime by Medical Professionals Footnote ³⁰ published by Tsuneishi Keiichi had a significant impact on Unit 731 research in this period. Tsuneishi utilised a large amount of archival materials, including Fifty-Year History of the Army Medical School, Journal of the Army Medical Corps, Secret Records - Nagata Tetsuzan, Hygienic History of Army in the Great East Asian War and Report on the Study of Epidemic Prevention at the Army Medical School. Footnote ³¹ Tsuneishi analysed the establishment and expansion of Unit 731 from the perspective of the history of science and technology. Tsuneishi’s educational background in physics had a direct influence on his focus on a microscopic examination of scientific and technological history, and his extensive use and systematic analysis of archival materials provided a comprehensive account of the organisation, scope, and biological warfare and human experimentation activities of Unit 731.

Tsuneishi conducted multiple visits to the U.S. National Archives in Fort Detrick and Dugway Proving Ground for on-site research and was the first to discover the U.S. collection of archival materials on Japanese biological warfare. He then selected about five hundred pages from the archives and translated them into Japanese, and included the translated text in the book Target Ishii: Espionage by Unit 731 and the U.S. Army. Footnote ³² In 1994, Tsuneishi wrote Organized Crime by Medical Professionals based on the newly discovered Epidemic Prevention Research Report of the Army Medical School. Footnote ³³ Compared to previous works, the authenticity, accuracy, and reliability of Organized Crimes by Medical Professionals was greatly improved.Footnote ³⁴ In this period, studies on Unit 731 entered the realm of sophisticated academic studies, incorporating elements such as standardised verification, fact-checking, and the integration of history and theory.

The driving force of literature and history: The Devil’s Gluttony and its implications

In 1981, well-known Japanese writer Morimura Seiichi’s book The Devil’s Gluttony Footnote ³⁵ gained popularity in Japan. From 19 July to 3 October 1981, the work was serialized in the Japanese Communist Party’s newspaper Shimbun Akahata. It was later published as a three-volume book, becoming a bestseller that underwent multiple revisions and reprints. Over three million copies were sold in Japan, and the work was translated into Chinese and Russian to be sold overseas. As a result, the history of Unit 731 caught the public’s attention and had a tremendous impact on Japanese society. At the same time, studies on Unit 731 drew the continued attention of the academic community, and an increasing number of Japanese scholars became involved in this scholarly discussion. This marked the beginning of systematic research on Unit 731. After The Devil’s Gluttony gained popularity in Japan, Morimura and Ikebe Shinichiro, two well-known Japanese musicians, established the Devil’s Gluttony Chorus. Over the following decades, the Chorus performed in hundreds of performances across Asia, Europe, and the United States on the themes of anti-war, peace, and humanitarianism, which further increased awareness of Unit 731 around the world. Morimura Seiichi continued to publish and re-print a series of books, including The Devil’s Gluttony, Proof of Man, New Proof of Man,Footnote ³⁶ and Unit 731 on Trial,Footnote ³⁷ leading to a significant impact on the publishing industry as well as growing concerns within Japanese society. For example, Shimamura Takashi’s 3,000 Human Experiments: The Crimes of the Japanese Army’s Germ Warfare Unit Footnote ³⁸ was revised and reprinted, and Ishida’s The Devilish Japanese Military Doctor Footnote ³⁹ and Hiyama Yoshiaki’s documentary novel Pursuit of the Biological Warfare Unit Doctor Footnote ⁴⁰ were published to a great reception in Japanese society. The profit motive of the Japanese publishing industry further promoted the publication of works on topics related to Unit 731. During this period, memoirs of witnesses and people who were associated with Unit 731 were published one after another. These include Army Surgeon Lieutenant colonel Ryoichi Naito’s A Collection of Ryoichi Naito’s Miscellaneous Writings in 1980,Footnote ⁴¹ Yoshikai Natsuko’s Unforgettable Memory: A Record of the Vivisection of Dr. Yuasa, a Military Doctor Footnote ⁴² in 1981, Gunji Yoko’s Testimony: Unit 731 and the Ishii Detachment Footnote ⁴³ and Uncovering the Truth: Ishii’s Germ Warfare Unit Footnote ⁴⁴ in 1982, Akimoto Sueo’s Questioning the Logic of Medicine: Based on Experiences in Unit 731 Footnote ⁴⁵ in 1983, Koshi Sadao (from transportation team)’s The Rising Sun Is Dyed Red with Tears: Confessions of a Member of Unit 731 Footnote ⁴⁶ in 1983, Yoshimura Hisato’s (leader of frostbite research team) Looking Back on My 77th Year Footnote ⁴⁷ in 1984, Takezawa Masao’s (member from water purification department) Tōgō Society JournalFootnote ⁴⁸ and 731 research society’s Biological Warfare Unit Footnote ⁴⁹ in 1986.

Outside of Japan, Britain was the first European country that became concerned about the history of Unit 731. British authors Robert Harris and Jeremy Paxman cowrote A Higher Form of Killing: The Secret Story of Chemical and Biological Warfare,Footnote ⁵⁰ which was first published in English in 1982, and then in Chinese by Qun Zhong Publishing in 1988. A British independent television production company produced a documentary Unit 731: Did the Emperor know? in August 1985.Footnote ⁵¹ The two producers of the documentary, Peter Williams and David Wallace, published a book titled Unit 731: Japan’s Secret Biological Warfare in World War II Footnote ⁵² four years later. The book became a representative work of European and American academia in the period and remains one of the most cited works in the English language on this topic.Footnote ⁵³ Scholars from the US also published several influential works on the issue of Unit 731. For example, John Powell published an article ‘A hidden chapter in history’ in the Bulletin of the Atomic Scientists Footnote ⁵⁴ in October 1981 and this article revealed for the first time the secret US-Japanese deal on biological warfare. Sheldon Harris from the Department of History of California State University published an article named ‘Japanese Biological Warfare Experiments and Other Atrocities in Manchuria, 1932-1945, and the Subsequent United States Cover Up: A Preliminary Assessment’.Footnote ⁵⁵ Harris then conducted extensive fieldwork in China and Japan, which allowed him to finish the manuscript of Factories of Death: Japanese Biological Warfare: 1932-45, and the American Cover-up Footnote ⁵⁶ in 1994. Harris’s book had influential status in European and American academia and was later translated into Japanese and Chinese.Footnote ⁵⁷

During this period, there were several dissertations by graduate students from universities in the U.S. on the topic of Unit 731. For example, Walter Eugene Grunden dedicated a chapter in his dissertation to discuss chemical and biological warfare using sociological research methodology in Science under the Rising Sun: Weapon Development and the Organization of Scientific Research in World War II Japan. Footnote ⁵⁸ The dissertation analysed the unique characteristics of Unit 731 from the perspective of the vertical social structure and traditional norms of behaviour in wartime Japan. In addition to the use of American materials, Japanese scholar Ota Masakatsu published Unit 731’s Immunity: Secret Files of the Biological Warfare Unit in 1999.Footnote ⁵⁹ The book utilised the oral testimonies of Lieutenant Colonel Niizuma Seiichi and abundant material from the collections, which allowed the author to comprehend the process of Niizuma’s secret liaison and negotiation with Kitano Masaji and Masuda Tomosada in conjunction with the US military forces.

The lawsuit of Ienaga: the ‘push’ of local movements

In the 1980s and 1990s, the textbook lawsuits of Ienaga SaburoFootnote ⁶⁰ created an uproar in the Japanese government and in civil society. When reviewing Japan’s high school history textbooks, the Japanese Minister of Education proposed a revision to ‘completely delete’ all content on Unit 731.Footnote ⁶¹ In the end, the Supreme Court of Japan rejected the proposal of the Minister of Education. The social impact generated by this case was not contained to the issue of the textbook litigation itself. News and public opinion concerning the court’s judgment broadened the case’s impact within and beyond Japan, and promoted Japanese society’s further recognition of the criminal history of Unit 731.Footnote ⁶²

The important roles in ‘historical investigation’ and ‘academic solidarity’ during the Ienaga lawsuit played by Morimura Seiichi and Matsumura Takao were not widely known by the public.Footnote ⁶³ Importantly, the Supreme Court of Japan referred to the ‘results of historical research’ to reach a judgement on Ienaga’s lawsuit. As a result, the research, investigation, and narration of Morimura and Matsumura provided strong historical evidence for the lawsuit.Footnote ⁶⁴ Morimura’s Unit 731 on Trial explained the motivation, process, and conclusion of the investigation of the historical facts of Unit 731, and Morimura Seiichi’s Witness Statement was submitted to the Court as supplementary evidence. Importantly, Unit 731 on Trial also included the witness statements of Hata Ikuhiko and Eguchi Keiichi.Footnote ⁶⁵ Matsumura Takao utilised 168 pages to record ‘Opinions of Matsumura Takao’ and ‘Testimony of Matsumura Takao’ in Arguments for Unit 731. The work cited archival evidence in Japanese, English, and Russian, and in particular, it presented official direct historical sources kept by Japan’s Ministry of Foreign Affairs and Ministry of Defense. Matsumura also gave a detailed account of the origins, contents, and values of his edited work Documents Created by Unit 731. Footnote ⁶⁶ Morimura and Matsumura introduced, commented on, and refuted the content of the textbook regarding Unit 731, compiled many historical facts, summarised the state of research, and drew objective conclusions, which had a wide social effect as the lawsuit continued to fester and had a direct impact on the dissemination and promotion of the historical facts of the Unit 731 in Japan and beyond.Footnote ⁶⁷

Furthermore, two large-scale lawsuits against Japan were initiated by Chinese civil society groups with strong support from well-known lawyers in 1995 and 1997.Footnote ⁶⁸ From 1995 to 2007, the two lawsuits were heard by the Tokyo District Court and the Tokyo High Court, which confirmed the facts of human experimentation victimisation and the facts of the crime of biological warfare, but both rejected the claims from the plaintiffs.Footnote ⁶⁹ During this period, legal experts, historians, sociologists, and the domestic and international media continued to pay attention to this event. The rapid intervention of media and its real-time reporting also drew a high degree of attention from Japanese society to this case. In particular, the simultaneous appearance of the Japanese legal team, victims, perpetrators, and third-party witnesses in court directed influenced the restoration of historical facts of bacteriological warfare, the determination of historical authenticity, and the final verdict of the Tokyo court.Footnote ⁷⁰ At the same time, Chinese and Japanese academic communities cooperated in the editing of the eight-volume Biological Warfare on Trial. Footnote ⁷¹ Biological Warfare on Trial recorded relevant materials concerning evidence collection, lawsuits, and judgements, thus effectively promoting international understanding of the history of Unit 731, human experimentation, biological warfare, and the US-Japanese deal, laying the groundwork for a wider range of investigations and research.

To summarise, research on the issue of Unit 731 during this second period was characterised by the following features: first, while Japanese academia still dominated research in the field, and while research findings were mainly published in Japanese, its influence was no longer confined to Japan, but had spread through translation to China, Europe, and the United States. Second, the 1980s marked the pioneering stage of academic research, and the 1990s marked a stage of rapid development, with the participation of scholars in the fields of science and technology, medicine, and education. Third, in contrast to the previous period, when the Japanese people were ‘fighting alone’, research groups were established, including the Japan Audit Bureau of Circulations, the Society for Disclosure of Historical Facts on Biological Warfare of the Japanese Army, the NPO Corporation Unit 731 Biological Warfare Resource Center, and the Society for the Study of the Problems of the Discovery of Human Bones on the Ruins of Military Medical Schools, among others. Lastly, academic research made great progress with the continuous excavation of English- and Japanese-language archival documents, and civil movements within Chinese and Japanese society promoted continuous in-depth investigations and research into Unit 731. At the same time, Japanese scholars gradually shifted their focus from unilateral investigation from the perspective of the victimising party to focusing on evidence collection that relied on the victimised party.

In-depth study by Japanese scholars from the perspective of medical history and ethics

At the beginning of the twenty-first century, Japanese scholars made important breakthroughs in terms of collecting, organising, and publishing historical materials. Major research outcomes include A Collection of Documents on Unit 731’s Biological Warfare Footnote ⁸⁰ and Report on Epidemic Prevention Research at the Army Medical School (Part 2). Footnote ⁸¹ Building on the discovery of wartime Japanese historical materials such as the Imoto Journal and the Kaneko Junichi Theses, these two books have achieved a breakthrough in confirming the basic historical details such as the time and place of Japan’s biological weapon attack, the mode of operation, and the number of victims of biological warfare.

Precisely due to the Japanese medical community’s sustained focus on studying Unit 731 from the perspective of medical history and ethics, studies of Unit 731 and its relationship with issues of war, medicine, and ethics increased in depth and comprehensiveness. For example, Omata’s Verification of Human Experimentation: Unit 731 and Nazi Medicine examined Germany as a comparator for the study of wartime Japanese doctors. Omata compared the similarities and differences between Japan and Germany before, during, and after the war in terms of historiography and medical historiography, historical understanding and ethical judgement, personal and organisational relationships, and law and medicine.Footnote ⁸²

With the establishment of the Research Society for 15 Years War and Japanese Medical Science and Service, hundreds of Japanese medical practitioners, clinicians, and ethicists were involved in discussions regarding Unit 731. This brought forward profound changes to the breadth of investigation and research on Unit 731. Japanese scholars investigated, researched, and promoted an understanding of the medical crimes committed by Unit 731 doctors, and have published more than four hundred papers and investigation reports on topics such as biological warfare, the history of medicine, human experimentation, responsibility for war, and ethical reflection.Footnote ⁸³ Japanese scholars have made new progress in horizontal expansion by venturing into comparative research in two areas. First, they began comparing the similarities and differences between the wartime medical practices of Japan’s Unit 731 and Nazi medical atrocities. They conducted this comparative analysis from a variety of perspectives, including through the lenses of nationalism, racism, organisational structures, budgetary systems, and medical systems.Footnote ⁸⁴ Second, they began to compare the historical narratives, discourse, and reflective practices of post-war Japan and post-war Germany on the issue of medical crimes, in order to elucidate the historical memories, ethical reflections, and contemporary values in different spaces and environments.Footnote ⁸⁵

In 2013, Nishiyama published War and Medicine within the framework of the Fifteen Years’ War and the Japanese medical field.Footnote ⁸⁶ The book examined the relationship between the War of Aggression against China and organisations in Japan’s medical community such as the Japanese Industrial Hygiene Society, the Japanese Health Society, and the Japanese Medical Association, revealing the war responsibilities and post-war perceptions of the these groups. In 2014 and 2016, Nishiyama and the other scholars edited two influential collections: NO MORE 731: The Japanese Army’s Biological Warfare Unit – A Conscientious Investigation by Medical Professionals Footnote ⁸⁷ and War and Unit 731, Universities and Medical University .Footnote ⁸⁸ In these works, Nishiyama selected eighteen articles from thirteen authors, including nine medical doctors, and examined medical education and the medical system in the context of fifteen years of war, focusing on issues such as wartime mobilisation, the ‘military-academic commonwealth’, war coordination, and post-war responsibilities at the Tohoku Imperial University School of Medicine, Kanazawa Medical University, Kyoto Imperial University, Tokyo Imperial University, and Kyushu Imperial University.

More recently, Tsuneishi Keiichi, in his book Complete History of Unit 731: The Ishii Institution and the Military Academic-Industrial Government Complex,Footnote ⁸⁹ not only reviewed the entire process of the establishment, expansion, and demise of Unit 731, but also referred to historical materials such as The Diary of Imoto Kumao, The Report of Kaneko Junichi, and the doctoral dissertations of Kyoto University to uncover the plague-bacteria warfare operations of the Unit 731 at the specific locations of Nong’an, Quzhou, Ningbo, Changde, Guangxin, Guangfeng, and Yushan. In April 2022, Unit 731 and the University Footnote ⁹⁰ edited by Professor of Clinical Medicine at Kyoto University and former director of Kyoto Central Hospital, Yoshinaka Takeshi, was published by Kyoto University Press in Japan. The book is divided into two parts: the first is the Japanese translation of Unit 731: The Devil’s Laboratory – Auschwitz in the East (see section 3.3), and the second part consists of eleven essays written by eleven Japanese scholars, including Yamamuro Shinichi, Mitsuyama Masao, Tsuchiya Takashi, and Minami Norio. This work became one of the more influential academic works of recent years.

Overseas encounters: research and ethical perspectives

Since the founding of ‘the Research Society for 15 Years War and Japanese Medical Science and Service’ on the initiative of Japanese physicians in 2000, an increasing number of Japanese doctors and medical historians have directly participated in investigating the historical evidence of Unit 731. The intensifying participation of the Japanese medical community further drew the attention of the European and American bioethics academic bioethicists to the issue of Unit 731. Since 2000, scholars from the United States, the United Kingdom, Russia, Belgium, and other countries have published nearly 100 articles on Unit 731 in international journals of medicine and bioethics, including the American Journal of Bioethics, Asian and International Journal of Bioethics, and The Lancet. Scholars mostly discussed the issue from the perspective of bioethics and engaged in in-depth academic dialogues on the occurrence, harm, impact, and response to medical crimes in wartime Japan. For example, in 2006 overseas Chinese scholar, Jingbao Nie of New Zealand, published an article ‘The US Cover-up of Japanese Wartime Medical Crimes: Complicity in the Name of National Interest and Two Suggestions for Contemporary Action’Footnote ⁹¹ in The American Journal of Bioethics. Nie’s article clearly laid out the historical facts surrounding the history of the US cover-up, including its motivations, its global moral significance, and concrete proposals for steps forward. This article revealed that the United States secretly traded human experimentation intelligence with Unit 731 after the war while simultaneously covering up Unit 731’s war crimes. Based on Nie’s article, the American Journal of Bioethics subsequently published six discussion articles at the same time, and a relatively intense academic debate began: some scholars believed that the US bioethics committees and the US government should respond as soon as possible and sincerely apologise; other scholars believed that it may be more valuable to prompt the United States to reveal the facts and underlying causes of Japanese and Nazi medical crimes in Japan so that others can learn from these ethical lessons and historical experiences. Jingbao Nie’s article recommended that ‘the US government issue a formal apology, making it clear that it now condemns the Japanese war crimes including those associated with BW activities and human experimentation, and offers compensation in some form to redress its own actions in covering up these atrocities’.Footnote ⁹² Katerin Devolder in her article ‘U.S. Complicity and Japan’s Wartime Medical Atrocities: Time for a Response’ stated that ‘Perhaps a statement, instead of an apology (like in the Guatemala case), would be an appropriate response, as well as directing the Bioethics Commission to write a brief report on the U.S. involvement in the coverup of the Japanese medical experiments’.Footnote ⁹³ Julie Aultman in the article ‘When Saying Sorry Is Not Enough: Acknowledging Past Wrongs in Human Subjects Research’ concluded that ‘a public apology may carry little meaning compared to alternative actions such as acknowledging the unethical Japanese experiments and the victims of these crimes, and ultimately preventing future faulty ethical reasoning and wartime exigency through enhanced critical thought, public discourse, ethics education and advisement, and responsiveness to global values and human rights’.Footnote ⁹⁴

Following this series of articles, Kenneth L. Port, a legal scholar who has studied in Japan for seven years and is fluent in Japanese and familiar with Japanese culture, approached Unit 731 research from a different perspective. Focusing on Ishii Shiro as a historical figure, Port’s book Deciphering the History of Japanese War Atrocities: The Story of Doctor and General Shiro Ishii Footnote ⁹⁵ utilised American archives and on-site investigations to microscopically examine Ishii’s life from the perspective of his family background, schooling, military experience, secret dealings, and post-war life. Shortly afterwards, Jeanne Guillemin’s Hidden Atrocities: Japanese Germ Warfare and American Obstruction of Justice at the Tokyo Trial returned to the theme of the US cover-up. Rather than focusing on the examination of the criminal evidence of Unit 731, Guillemin’s work explored the sharing of information on biological warfare between the United States and the UK, the detailed process of the negotiation between the United States and Japan, the obstruction of justice at the Tokyo trial, and the transmutation between national interests, international rules, and medical ethics.Footnote ⁹⁶ Focusing more on the details of Unit 731 experimentation, through an examination of testimony from the Khabarovsk War Crime Trials, Canadian scholar Kishor Johnson in his 2022 article ‘A Scientific Method to the Madness of Unit 731’s Human Experimentation and Biological Warfare Program’ argued that Unit 731’s human experiments were scientifically rigorous by the standards of the time. He concluded that ‘Given the Japanese scientists’ wealth of background knowledge in microbiology, access to the most recent literature, and active participation in the broader scientific community, the investigators were well prepared to integrate the scientific method into their program of human experimentation’.Footnote ⁹⁷

More recently, Valerie J. Cranmer argued in the article ‘In Judgment of Unit 731: A Comparative Study of Medical War Crimes Trials after World War II’ that “the prosecution of the crimes of the Imperial Japanese Army’s Unit 731 are often compared to the prosecution of the crimes of the Nazi doctors. These comparisons emphasize immunity for the Japanese, whereas the Nazis were prosecuted for their actions. However, this comparison is an inaccurate one, since their composition, scope, and framework were different.”Footnote ⁹⁸ Cranmer contended that “the United States avoided prosecuting Unit 731 because they could not replicate the same clear legal framework used to successfully prosecute the Nazis. The Soviet Union recognized the strategic implications of the United States’ decision not to try Unit 731 and saw an opportunity to strike a moral blow, not only by convicting 12 Japanese military members at the Khabarovsk Trial.”Footnote ⁹⁹ The article also noted that Nazi Germany, Britain, the United States, and the Soviet Union all had programs that investigated the use of BW or chemical warfare weapons during World War II. However, Unit 731 is used as the prime example to describe the evils of BW. Analysis of Unit 731 rarely extends beyond the program’s existence and human experimentation in its research. Moreover, writers treat BW programs worldwide irrespective of one another and rarely analyse them as an aggregate to define a general global trend in the interwar period of states that developed and researched BW.Footnote ¹⁰⁰

Chinese academia: from the periphery to centre stage

Following the litigation campaign against Japan, the discovery and disclosure of the ‘special transfer’ archives, and the opening-up of the archives of the United States and Japan, several Chinese institutions including Shanghai Jiao Tong University, the Exhibition Hall of Crime Evidence of Japanese Army Unit 731, the Harbin Academy of Social Sciences, and Hunan University of Arts and Science began to focus on Unit 731 research. Chinese scholars gradually utilised original archives, focusing not only on macro issues such as the preparation, implementation, and impact of human experimentation and biological warfare but also on the in-depth excavation, analysis, and interpretation of specific cases in localised contexts, while turning towards multi-dimensional research in history, archaeology, ethics, and the history of medicine.

Over the past 20 years, there have been two main types of outputs from Chinese academia: compilations of primary sources and academic analysis. In the field of evidence compilation, for example, the National Archives Administration of China published the Selected Confessions of Japanese War Criminals Who Invaded China (120 volumes),Footnote ¹⁰¹ which included the confessions and written records of the former members from Unit 731, including Sakakibara Hideo and Hata Masayoshi. In 2015, the China Peace Publishing House published the Factual Record of the Crimes of the Unit 731 of the Japanese Army in Invasion of China (60 volumes), which included archival data on Japan’s biological warfare preserved by China, Japan, and the United States.Footnote ¹⁰² The Japanese materials were collected from the Ministry of Defense of Japan, the National Public Library, and the National Library of Congress. As for the materials on the American side, they mainly came from the Library of Congress and Stanford University, as well as from Chinese official archives. This series has high historical and research value, and its compilation and publication have allowed Chinese scholars to surpass the comprehensiveness and scope of the previous compilation of historical materials on Unit 731 by Japanese scholars. In 2018, the China Social Sciences Press published a series of five books in the volume Studies on the Biological Warfare Waged by the Japanese Invaders in Changde,Footnote ¹⁰³ which mainly focused on biological warfare in Changde.

A distinctive characteristic of the investigation and research on Unit 731 of the Chinese academic community is the application of archaeological theory and methods to the field of medical history. Archaeological Excavation Report of the Former Site of the Bacterial Laboratory and Special Prison of the Japanese Invading Army’s Unit 731 Footnote ¹⁰⁴ contributed to the result of the creation of a new paradigm for the integration of historical and archaeological research. This work supplements, rectifies, reshapes and introduces a new research methodology to studies of Unit 731. This report was not entirely confined to the analysis of archaeological findings, but instead placed archaeological findings in a multidisciplinary context of documentary records, interviews with the historical witnesses, and oral histories. In addition, Namelist of the Kwantung Army’s Epidemic Prevention and Water Supply Department,Footnote ¹⁰⁵ Namelist of the Unit 1855,Footnote ¹⁰⁶ and Namelist of the Southern Army’s Epidemic Prevention and Water Supply Department Footnote ¹⁰⁷ by Yang Yan-jun; Information on Japan’s Biological Weapons Operational Survey (6 volumes) by Wang Xuan and Kondo Shoji; and Biological Warfare Archives of the Japanese Invasion Forces by the National Library of China Publishing House were published in recent years. While the content of the Chinese archives has some overlap with the US archives, the two archival collections also differ in scope and textual organisation.

In the field of academic research, historical excavation still dominates the study of Unit 731, and research outcomes under the perspectives of medical history, ethics, and archaeology continue to emerge. Some major publications include Japan’s Biological Warfare Against China Footnote ¹⁰⁸ by Zhiyuan Chen, Research Report on the Crimes of Japanese Biological Warfare Against China Footnote ¹⁰⁹ by Zhonghou Xie, and A History of Biological Warfare Footnote ¹¹⁰ by Jianxin Zhu. These works documented the existence, wartime behaviour, war responsibility, war damage, and post-war impact of forces engaged in biological warfare. With the confirmation of these macro-issues, a number of micro-issues in the field of the history of biological warfare have become the subject of new research perspectives, as scholarly attention shifted from the study of Unit 731’s global significance to the detailed analysis of specific cases. There were some major research papers, such as ‘The Main Content, Historical Value, and Significance of Newly Discovered Documents on Japanese Biological Warfare’Footnote ¹¹¹ by Xiliang Wang, ‘Unit 731 and the Allied POW Camp in Shenyang’Footnote ¹¹² by Gao Jian, and ‘Examining the Personnel Composition of Unit 731’Footnote ¹¹³ by Yanjun Yang. In particular, Yang’s ‘Examining the Personnel Composition of Unit 731’ relies on the article ‘Namelist of the Kwantung Army’s Epidemic Prevention and Water Supply Department’ and uses relevant historical materials of the Japan Ministry of Defense and the National Archives of Japan to clarify major historical issues such as the composition of Unit 731, its personnel composition, source of personnel, and its overall troop size, leading to the promotion of further related research.

A significant advance by Chinese academics came from the publication of Tam Yuehim and Yang Yanjun’s English-language book, titled Unit 731: Laboratory of the Devil, Auschwitz of the East Footnote ¹¹⁴ in 2018. It is one of the most comprehensive English-language scholarly works published overseas by Chinese scholars, which utilised materials from the US National Archives analyse the detailed process of the US military’s investigation into Unit 731 and record the traumatic memories of the families of victims who had suffered from human experimentation, an issue that had been less explored in previous works.

Overall, research on Unit 731 in China has shown two distinctive features. First, Chinese research tended to cross geographical and disciplinary barriers of research. With the deepening of research and active academic exchanges between regions, Chinese scholars were no longer confined to the scope of ‘local history’ but were gradually paying attention to the study of the preparation, implementation, and impact of biological warfare from a global perspective. Scholars from archaeology, medical history, and cultural heritage have also participated in the scholarly discussion on the history of biological warfare, which has led to the organic integration of research institutes with specialised institutions for site survey and archaeological excavation and display.

Second, Chinese research is starting to tend towards developing increasingly standardised, rigorous, and scientific methodology and analysis. For a long time, due to the constraints of pragmatic factors such as the difficulty of collecting historical data and the lack of research funds, Chinese scholars were not able to make much use of the core archives and did not adequately identify relevant historical data, leading to a failure to distinguish between the damage caused by epidemics that resulted from biological warfare and epidemics from natural causes. As a result, in academic research, there have been a few cases in which epidemic prevention records have been used as historical materials of biological warfare, leading to a mistaken recognition of people killed by natural epidemics as victims of biological warfare, and as a result, leading to an overestimation of the number of people killed and injured by biological warfare.Footnote ¹¹⁵ With the improvement of research conditions and the gradual enhancement of levels of research, a number of Chinese academics have strengthened the excavation and utilisation of foreign archives, improved the accuracy of empirical research, improved the process of argumentation, and drawn historical conclusions in a more cautious and evidence-based manner.

In addition, Korean scholars have published more than ten research papers in Korean journals on the topic of Unit 731, such as ‘Bare Life in Manchuria and the Victims of Human Experiments in the Special Prison of Unit 731’Footnote ¹¹⁶ by Suh Yi-Jong from Seoul National University and ‘The Memory of Biological Warfare and New Directions for Patriotic Education Base Construction in China’Footnote ¹¹⁷ by Sihn Kyu-Hwan from Yonsei University. Russian scholars including Alepko have published more than 20 papers in Russian journals, including The Khabarovsk War Crimes Trial of 1949 and the Cruel Human Experiments of Japan’s Unit 731. Footnote ¹¹⁸

To conclude, research on Unit 731 since the twenty-first century exhibits several key characteristics. First, the extensive involvement of the Japanese medical community and the academic interest from European and American bioethics scholars led mainstream research on Unit 731 during this period to be dominated by observations and analyses from the perspectives of medical history and ethics. Thus, there were both horizontal comparative studies of wartime Japan, post-war Japan, and Nazi Germany and post-war Germany, as well as vertical in-depth studies within different disciplines. Second, Japanese scholars utilised the Research Society for War and MedicineFootnote ¹¹⁹ as their main academic platform, focusing on the experience of war, and the fate of individuals from the perspectives of medical history, military medicine, and sociology. These Japanese scholars published hundreds of papers in the fields of the history of war and medicine, medicine and ethics, and covering topics including the culpability of those involved in bacteriological wars, medical crimes, and civil lawsuits. Compared with the twentieth century, the number and quality of research have increased considerably. Third, Japanese scholars tended to overlook the research findings of Chinese scholars in the investigation and research on biological warfare crimes and were more inclined to pay attention to the works of European and American scholars. Finally, European, American, South Korean, and Russian scholars have also contributed actively to the academic discussion during this period, not only publishing nearly one hundred academic papers but also more than ten books related to Unit 731, illustrating the beginnings of a productive East-West academic interaction.