Antiquity and Middle Ages Rudimentary forms of biological warfare have been practiced since antiquity. The earliest documented incident of the intention to use biological weapons is recorded in
Hittite texts of 1500–1200 BC, in which victims of an
unknown plague (possibly
tularemia) were driven into enemy lands, causing an epidemic. The Assyrians poisoned enemy wells with the fungus
ergot, though with unknown results.
Scythian archers dipped their arrows and Roman soldiers their swords into excrements and cadavers – victims were commonly infected by
tetanus as result. In 1346, the bodies of
Mongol warriors of the
Golden Horde who had died of
plague were thrown over the walls of the
besieged Crimean city of Kaffa. Specialists disagree about whether this operation was responsible for the spread of the
Black Death into Europe, Near East and North Africa, resulting in the deaths of approximately 25 million Europeans. Biological agents were extensively used in many parts of Africa from the sixteenth century AD, most of the time in the form of poisoned arrows, or powder spread on the war front as well as poisoning of horses and water supply of the enemy forces. In
Borgu, there were specific mixtures to kill,
hypnotize, make the enemy bold, and to act as an antidote against the poison of the enemy as well. The creation of biologicals was reserved for a specific and professional class of medicine-men. Following instructions of his superior, Colonel
Henry Bouquet, the commander of Fort Pitt,
Swiss-born Captain Simeon Ecuyer, ordered his men to take smallpox-infested blankets from the infirmary and give it to a Lenape delegation during the siege. A reported outbreak that began the spring before left as many as one hundred Native Americans dead in
Ohio Country from 1763 to 1764. It is not clear whether the smallpox was a result of the Fort Pitt incident or the virus was already present among the
Delaware people as outbreaks happened on their own every dozen or so years and the delegates were met again later and seemingly had not contracted smallpox. During the
American Revolutionary War,
Continental Army officer
George Washington mentioned to the
Continental Congress that he had heard a rumor from a sailor that his opponent during the
Siege of Boston, General
William Howe, had deliberately sent civilians out of the city in the hopes of spreading the
ongoing smallpox epidemic to American lines; Washington, remaining unconvinced, wrote that he "could hardly give credit to" the claim. Washington had already inoculated his soldiers, diminishing the effect of the epidemic. Some historians have claimed that a detachment of the
Corps of Royal Marines stationed in
New South Wales, Australia, deliberately used
smallpox there in 1789. Dr Seth Carus states: "Ultimately, we have a strong circumstantial case supporting the theory that someone deliberately introduced smallpox in the Aboriginal population."
World War I By 1900 the
germ theory and advances in
bacteriology brought a new level of sophistication to the techniques for possible use of
bio-agents in war. Biological sabotage in the form of
anthrax and
glanders was undertaken on behalf of the
Imperial German government during
World War I (1914–1918), with indifferent results. The
Geneva Protocol of 1925 prohibited the first use of chemical and biological weapons against enemy nationals in international armed conflicts.
World War II With the onset of
World War II, the
Ministry of Supply in the
United Kingdom established a biological warfare program at
Porton Down, headed by the microbiologist
Paul Fildes. The research was championed by
Winston Churchill and soon
tularemia,
anthrax,
brucellosis, and
botulism toxins had been effectively weaponized. In particular,
Gruinard Island in Scotland, was contaminated with anthrax during a series of extensive tests for the next 56 years. Although the UK never offensively used the biological weapons it developed, its program was the first to successfully weaponize a variety of deadly pathogens and bring them into industrial production. Other nations, notably France and Japan, had begun their own biological weapons programs. When the United States entered the war, Allied resources were pooled at the request of the British. The US then established a large research program and industrial complex at
Fort Detrick, Maryland, in 1942 under the direction of
George W. Merck. The biological and chemical weapons developed during that period were tested at the
Dugway Proving Grounds in
Utah. Soon there were facilities for the mass production of anthrax spores,
brucellosis, and
botulism toxins, although the war was over before these weapons could be of much operational use. , commander of
Unit 731, which performed human
vivisections and other biological experimentation The most notorious program of the period was run by the secret
Imperial Japanese Army Unit 731 during the
war, based at
Pingfang in
Manchuria and commanded by Lieutenant General
Shirō Ishii. This biological warfare research unit conducted often fatal
human experiments on prisoners, and produced biological weapons for combat use. Although the Japanese effort lacked the technological sophistication of the American or British programs, it far outstripped them in its widespread application and indiscriminate brutality. Biological weapons were used against Chinese soldiers and civilians in several military campaigns. In 1940, the Japanese Army Air Force bombed
Ningbo with ceramic bombs full of fleas carrying the bubonic plague. Many of these operations were ineffective due to inefficient delivery systems, During the
Zhejiang-Jiangxi Campaign in 1942, around 1,700 Japanese troops died out of a total 10,000 Japanese soldiers who fell ill with disease when their own biological weapons attack rebounded on their own forces. During the final months of World War II, Japan planned to use plague as a biological weapon against US civilians in
San Diego,
California, during
Operation Cherry Blossoms at Night. The plan was set to launch on 22 September 1945, but it was not executed because of
Japan's surrender on 15 August 1945.
1948 Arab–Israeli War According to historians
Benny Morris and
Benjamin Kedar, Israel conducted a biological warfare operation codenamed
Operation Cast Thy Bread during the
1948 Arab–Israeli War. The Haganah initially used typhoid bacteria to contaminate water wells in newly cleared Arab villages to prevent the population including militiamen from returning. Later, the biological warfare campaign expanded to include Jewish settlements that were in imminent danger of being captured by Arab troops and inhabited Arab towns not slated for capture. There was also plans to expand the biological warfare campaign into other Arab states including Egypt, Lebanon and Syria, but they were not carried out. Some British soldiers were also poisoned: causing the event to gain international attention.
Cold War In Britain, the 1950s saw the weaponization of
plague,
brucellosis,
tularemia and later
equine encephalomyelitis and
vaccinia viruses, but the programme was unilaterally cancelled in 1956. The
United States Army Biological Warfare Laboratories weaponized
anthrax,
tularemia,
brucellosis,
Q-fever and others. In 1969, US President
Richard Nixon decided to
unilaterally terminate the
offensive biological weapons program of the US, allowing only scientific research for defensive measures. This decision increased the momentum of the negotiations for a ban on biological warfare, which took place from 1969 to 1972 in the United Nation's
Conference of the Committee on Disarmament in Geneva. These negotiations resulted in the
Biological Weapons Convention, which was opened for signature on 10 April 1972 and entered into force on 26 March 1975 after its ratification by 22 states. == International law ==