Biochem Warfare

A Brief History

This timeline provides an overview of the history of Biochemical Warfare and focuses on Events, People, Places in Asia during the Second World War. It also includes key developments in International Law. ;xNLx;;xNLx;Credits: Key dates and selected information come from Jeanne Guillemin's Hidden Atrocities Timeline and Where did the Biological Weapons Convention Come From? Indicative Timeline and Key Events, 1925-75 by Alex Spelling, Caitríona McLeish, Brian Balmer

1763-05-07 23:57:00

Smallpox delivered via infected blankets

May 7, 1763: Early History British soldiers, besieged by American Indian tribes during Pontiac’s Rebellion, give blankets infected with the smallpox virus to tribal representatives.

1925-06-17 23:57:00

Geneva Protocol Prohibiting use in Warfare of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare

Seven years after WWI, the Geneva Protocol bans chemical and bacteriological weapons. Notably, the US and Japan decline to sign. John Singer Sargent’s painting “Gassed” vividly depicts the burning, blindness and death among defenseless troops, and becomes an icon of the suffering. The Protocol enters into force on February 8, 1928.

1927-02-10 23:57:00

Paris Peace Treaties incorporate limits on Chemical Warfare

Parties include the Allied nations with Bulgaria, Finland, Hungary, Italy and Romania.

1931-09-18 23:57:00

The Origins of Japan's Biochemical Warfare Program

After invading China’s resource-rich northeast, Japan creates the puppet state of Manchukuo where, under the Kwantung Army, it will establish its biological warfare program. (This video in an excerpt from Frank Capra's series of films "Why We Fight")

1932-01-01 12:13:04

Ishii Shiro conducts experiments on humans

Major General Ishii Shiro conducts disease freezing exposure tests on Chinese captives in Manchukuo.

1936-01-01 12:13:04

Unit 731

Pingfan, the enormous secret enclave for Ishii’s program, is built outside the city of Harbin in Manchukuo. Designated the “Anti-Epidemic Water Supply and Purification Bureau” but also known as Unit 731; It is commanded by Dr. Ishii; staffed by approximately 300 medical and scientific personnel and 2,700 support personnel.

1937-07-07 10:28:05

Outbreak of World War II in Asia

Japan begins a full scale war with China and, in 1940-41, incorporates attacks using plague-fleas with conventional air attacks on four Chinese cities (Ningbo, Jinhua, Quhzou, and Changde). Hundreds of Chinese civilians die from the epidemics

1940-10-01 12:12:02

Germ Warfare Attacks

General Umezu Yishijiro, head of the Kwantung Army in Manchukuo and known as “the Ivory Mask,” assists Ishii in waging germ attacks on China. Umezu was personally "requested" by the Emperor to sign the instrument of surrender on as the representative of the General Staff on 2 September 1945. was found guilty of Counts 1, 27, 29, 31 and 32 of waging a war of aggression and sentenced to life imprisonment on November 12, 1948.

1941-12-07 12:12:02

Attack on Pearl Harbor

The Japanese attack Pearl Harbor and cause the United States to declare war on the Axis Powers (Germany, Italy, and Japan), with China as its major ally in Asia.

1942-05-01 12:12:02

Mass Attacks by Unit 731

Japan wages a campaign to destroy air bases and railroads in China’s Jiangxi and Zhejiang Provinces and enlists General Ishii, under the auspices of the Kwantung Army’s Unit 731, to conduct simultaneous mass attacks of plague, anthrax, cholera, glanders and other infectious diseases.

1945-08-06 12:12:02

US drops the first Atomic bomb over Hiroshima

The United States drops an atomic bomb on Hiroshima. Approximately 70,000 Japanese were immediately killed. After five years, another 140,000 succumbed to the effects of radiation.

1945-08-09 12:12:02

The US bombs Nagasaki

An atomic bomb is dropped on Nagasaki, killing 40,000 on impact, with 140,000 subsequent victims. On August 14, Emperor Hirohito agrees to surrender. (

1945-09-02 12:12:02

Japan Surrenders

On the deck of the USS Missouri in Tokyo harbor, US General of the Army Douglas MacArthur, the Supreme Commander for the Allied Powers (SCAP), conducts the signing of the surrender agreement, which included a mandate for war crimes prosecution. Now Japan’s chief of staff, General Umezu signs the agreement, along with Foreign Minister Shigemitsu Mamoru (with cane).

1946-01-31 13:19:02

The Chief Prosecutor for the IMTFE is appointed

Chief of counsel for the International Prosecution Section, Joseph B. Keenan enjoys the media spotlight, leaving administration to his staff and UK lawyers. US prosecutor Frank S. Tavenner often takes his place at IPS.

1946-01-31 13:19:02

China assigns the head of its Prosecution

Hsiang Che-chun (Xiang Zhejun), chief prosecutor for the Chinese Division, intends to charge Japan with the plague attacks and chemical warfare, along with other war crimes, such as the notorious “Nanjing Massacre” from 1937 loom large.

1946-04-29 10:35:43

Reading of the indictments at the IMTFE

The IMTFE officially opens with the reading of the indictment of the defendants, brought by bus to the court from Sugamo Prison. Tojo Hideki, former prime minister, General Umezu and at least four others were early supporters of General Ishii.

1946-04-29 10:35:43

The IPS decides not to pursue the prosecution of Biochem Warfare against Japan

G-2 intervenes at the IPS to delete well-documented chemical warfare charges against Japan and impose strict restrictions on witness selection and interrogation. G-2 also blocks Sutton’s access to a crucial first-hand witness of the Changde plague attack, while pursuing secret interrogations of Unit 731 scientists that will reveal war crimes.

1946-09-01 08:37:04

Murray Sanders interviews Unit 731 scientists

As part of the Scientific Intelligence Survey of Japanese weapons expertise, microbiologist Murray Sanders from the US biological warfare program conducts interviews with former Unit 731 scientists and General Umezu, who all insist Japan had no germ warfare aims. Sanders is guided by Dr. Naito Ryioshi, formerly of Pingfan.

1946-09-01 10:35:43

Soviets capture Unit 731 scientists

Having invaded Manchukuo soon after Japan’s surrender, the Soviets were able to capture a group of Unit 731 scientists. Armed with two incriminating testimonies, Soviet prosecutors propose jointly presenting germ warfare charges with the United States. Frank Tavenner refuses and the prosecution continues with its often disrupted and disorganized proceedings.

1946-09-17 13:19:02

The creation of the IMTFE

General MacArthur announces the creation of the IMTFE (International Military Tribunal for the Far East), based on the same framework as the Nuremberg IMT. In addition to the US, UK, Soviet Union, and France, China, the Netherlands, Australia, New Zealand, and Canada, and later India and the Philippines are asked to nominate judges and chief prosecutors.

1946-11-01 07:15:57

Major General Charles Willoughby interrogates Unit 731 scientists

Major General Charles Willoughby, head of US Military Intelligence (G-2) in Tokyo, pursues interrogations of Unit 731 scientists. He works in close cooperation with Major General Alden Waitt, head of the Army’s Chemical Warfare Service and its biological warfare program, both eclipsed by atomic weapons and scheduled for elimination. Fleet Admiral William Leahy, head of the Joint Chiefs of Staff, is alerted to Japan’s biological weapons by the State-War-Navy Coordinating Committee (SWNCC). Two 1947 memoranda by Willoughby revealed not only full U.S. participation in allowing the Japanese medical torturers who escaped to Tokyo to go free in exchange for information, but that the Pentagon actually paid them.

1947-01-01 22:48:47

Soviet Prosecutor Lev N. Smirnov seeks access to Ishii Shiro

Arriving in Tokyo a stellar performance at Nuremberg, Soviet prosecutor Lev Smirnov agitates behind the scenes for access to General Ishii and other Unit 731 scientists being interrogated by G-2. Agreeing, the SWNCC orders G-2 to delay until it is sure the scientists will reveal nothing of importance to the Soviets.

1947-01-24 21:54:23

David Nelson Sutton goes on a fact-finding visit to China

To help Prosecutor Hsiang, US prosecutor David Nelson Sutton is sent to find evidence of the plague attacks in China, but lacking eye-witnesses from targeted cities, he finds the evidence unconvincing.

1947-05-03 12:29:35

Gen. Douglas MacArthur shields Unit 731 war criminals

General MacArthur petitions the Joint Chiefs, now headed by General Dwight Eisenhower, for either an official pardon for the Unit 731 war criminals or their continued protection by G-2. Meanwhile, the Doctors Trial in Nuremberg has begun exposing Nazi medical experimentation closely resembling the now revealed Japanese atrocities. Finally interviewed by Smirnov in June, Ishii and others deny all charges of war crimes.

1947-12-01 12:29:35

US Army pathologists' report on Japanese Biological Warfare

In a report on the Japanese autopsies of victims of anthrax, plague, glanders, and other disease experiments, two US Army pathologists urge continued protection of the Unit 731 scientists and urge caution against the data “falling into other hands,” that is, to the Soviets.

1947-12-01 17:05:56

Tojo is the last witness to testify for the defense

Defense lawyers present their case, with a confident Tojo the last defendant to testify. By February the Soviets have let pass their opportunity to enter germ warfare charges, making an official US immunity bargain with Ishii and his cohort unnecessary.

1948-04-16 03:03:19

The Prosecution's Summation delivered by Frank Tavenner

The IMTFE proceedings end with Frank Tavenner, often at the podium during the trial, giving the prosecution’s closing speech.

1948-10-01 22:48:47

The Nuremberg Trial Verdicts are announced

After less than a year, verdicts for the Nuremberg IMT are announced. The tribunal earns great praise from President Truman, in contrast with the Tokyo trial where proceedings lag.

1948-11-12 12:11:38

The sentences of the IMTFE defendants are read

The sentences of the Japanese defendants are announced, with Tojo and six others condemned to death. General Umezu and most others receive long sentences, to be commuted after 1952, when Japan regained its sovereignty and a popular backlash against the trial emerged.

1949-12-01 07:54:13

Expansion of Biochemical Warfare Programs during the Cold War

In the context of the Cold War, the US biological weapons program expands, with an actively aiming for mass attacks with bombs and sprays, mainly on Soviet targets, while nerve gas and other chemical weapons are developed, leading to decades of “fall out” as other nations, large and small, build their CBW arsenals.

1949-12-25 12:11:38

The Soviet Khabarovsk Trial

In the Siberian city of Khabarovsk, the Soviet Union puts a dozen Unit 731 scientists and military officials on trial. The former commander of the Kwantung Army General Yamada Otozo (successor to Umezu) testifies to the unit’s war crimes. The trial was dismissed in the West as anti-American propaganda and a Stalinist “show trial.”

1954-10-23 23:57:00

Modified Brussels Treaty

The Modified Brussels Treaty, which creates the Western European Union, is signed with the accession of West Germany which agrees to a ban on any production of atomic, chemical and biological weapons on its territory.

1955-05-15 23:57:00

Austrian State Treaty

Austrian State Treaty signed which also contains prohibitions on production of atomic, chemical and biological weapons on its territory.

1959-11-20 23:57:00

UN Resolution 1378 on General and Complete Disarmament

The United Nations (UN) General Assembly adopts resolution 1378 on ‘general and complete disarmament’. This follows proposals made by the UK on September 17 and the USSR on September 18 at the UN Disarmament Commission, proposals which include CBW disarmament. Responsibility is passed to the newly created Ten-Nation Disarmament

1962-01-01 06:03:21

Draft Resolution by Hungary denouncing US use of Agent Orange in Vietnam

With the escalation of the conflict in Vietnam, some international criticism is directed towards the US for the use of RCAs and herbicides. At the 21st session of the UN General Assembly, Hungary introduces a draft resolution stating that their use in warfare is prohibited by the Geneva Protocol and international law. The US responds that the Geneva Protocol does not apply to nontoxic gases and chemical herbicides.

1962-01-12 23:57:00

Agent Orange used in Vietnam

The US and South Vietnamese Militaries begin using herbicides and defoliants (Project Ranch Hand) against the National Liberation Front (NLF) to impact on food supplies and jungle foliage. Riot-Control-Agents are supplied to the Army of the Republic of Vietnam (ARVN) for use in civil disturbances and against the NLF.

1962-03-15 06:03:21

USSR submits to the 18 Nation Disarmament Committee

The USSR submits to the newly created Eighteen Nation Disarmament Committee (ENDC) at Geneva, a Draft Treaty for 'general and complete disarmament' which includes provisions to ban CBW, thus keeping the two weapons interlinked.

1966-12-31 06:03:21

A watered-down Resolution is passed

Amendments introduced to the Hungarian draft resolution by the US, UK, Canada and Italy leads to UN resolution 2162B, which calls instead for 'strict observance by all states of the principles and objectives of the protocol'. It also notes that the ENDC has the task of seeking an agreement on the cessation of the development and production of CBW.

1968-08-06 06:35:55

ENDC recommends study on the effects and use of Biological Weapons

At the ENDC UK Disarmament Minister, Fred Mulley, tables a working paper, based on work done by the Foreign and Commonwealth Office's (FCO) Arms Control and Disarmament Research Unit (ACDRU) and Atomic Energy and Disarmament Department (AEDD), on the prohibition of Microbiological Warfare. The ENDC recommends to the General Assembly that the Secretary General appoint a group of experts to study the effects of the use of BW.

1968-12-20 06:35:55

UNGAS 2454A Requests a Report on CBW

The 23rd session of the UN General Assembly adopts resolution 2454A which requests the Secretary General to prepare a report on the problems of CBW, in accordance with the ENDC report, in time for consideration at the 24th session.

1969-06-01 06:35:55

UN Experts ob CBW is published

UN Experts Report on CBW is published. In the forward, UN Secretary- General, U Thant, recommends accession to the Geneva Protocol for unsigned / non- ratified countries; a clear affirmation that the Geneva Protocol covers the use in war of all CBW, including RCAs and herbicides; and states that prospects for general and complete disarmament would be strengthened by the elimination of CBW from military arsenals.

1969-11-29 07:54:13

Nixon announces the end of the US biological warfare program

Guided by his national security advisor Henry Kissinger, President Nixon announces the end of the US biological warfare program—the first renunciation of an entire class of weapons in US military history. Kissinger’s primary policy expert for this decision was Harvard biochemist Matthew Meselson, a dedicated advocate for the abolition of biological and chemical weapons.

1970-03-05 05:49:01

Treaty on the Non-Proliferation of Nuclear Weapons (NPT) Comes into force

The NPT aims to prevent the spread of nuclear weapons and weapons technology, to foster the peaceful uses of nuclear energy, and to further the goal of disarmament. The Treaty establishes a safeguards system under the responsibility of the IAEA, which also plays a central role under the Treaty in areas of technology transfer for peaceful purposes.

1972-04-10 10:06:26

Biological Weapons Convention bans state possession, development and transport of germ weapons

The Biological Weapons Convention bans state possession, development and transport of germ weapons. Although later secretly violated by the Soviet Union and rejected by outlier nations, the BWC reinforces important norms and complements the 1925 Geneva Protocol. (The convention takes effect in 1975)

1980-01-01 10:06:26

Revelations about Unit 731 trickle into the mainstream

After decades of secrecy, during which scientists like Dr. Naito enjoyed successful careers in medicine and industry, revelations of the cover up of Unit 731 war crimes finally surface. Starting in 2000, activist Wang Xuan spearheads the legal effort on behalf of Chinese victims. Japanese judges admit that atrocities were committed, but they deny compensation or an apology to the victims.

1993-01-01 10:06:26

The creation of the Chemical Weapons Convention

In the aftermath of the Cold War, the world community creates the Chemical Weapons Convention, a parallel to the Biological Weapons Convention, with added provisions to aid the state destruction of chemical stockpiles, including the tons of chemical weapons left behind by Japan in China.

Biochem Warfare

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