Biological warfare

• 1. Introduction

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  Biological warfare is as old as the written record. Hittite texts from somewhere between 1500 and 1200 BC describe victims of a plague being driven deliberately into enemy lands to spread an epidemic. That is the earliest known documented intent to use disease as a weapon. Nearly three and a half millennia later, the technique has been refined into something almost unimaginably more powerful. What made soldiers reach for pathogens instead of blades? Why did the world eventually try to outlaw an entire category of weaponry? And how does a weapon that cannot stop an advancing army in a single day become one of the most feared tools a nation or terrorist cell can possess?

• 2. From Arrows to Anthrax

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  Scythian archers dipped their arrows in excrement and rotting cadavers. The result was infection by tetanus. Roman soldiers are reported to have done the same with their swords. These early practitioners did not need to understand germ theory to notice that wounded enemies sometimes died of causes beyond the wound itself.

  In 1346, warriors of the Mongol Golden Horde besieging the Crimean city of Kaffa catapulted the corpses of their own plague-dead over the city walls. Specialists still debate whether this act helped spread the Black Death into Europe, the Near East, and North Africa, where roughly 25 million Europeans would eventually die.

  In Africa from the sixteenth century onward, biological agents appeared in a more organized form. Poisoned arrows and powders spread on the war front were common in many regions. In Borgu specifically, trained medicine-men held exclusive rights over the preparation of mixtures intended to kill, to hypnotize, to embolden troops, or to counteract an enemy's poisons. The craft was professional, guarded, and socially sanctioned.

  By the 18th century, biological sabotage had entered a new context: colonial warfare. In June 1763, during the French and Indian War, Swiss-born Captain Simeon Ecuyer was stationed at Fort Pitt, a British-held position under siege by Native Americans. Acting on orders from Colonel Henry Bouquet, Ecuyer's men retrieved smallpox-infested blankets from the infirmary and handed them to a Lenape delegation. A subsequent outbreak left as many as one hundred Native Americans dead in Ohio Country between 1763 and 1764. Whether the contaminated blankets caused that specific outbreak remains disputed, since the Delaware people experienced smallpox independently on a roughly twelve-year cycle and the same delegates who received the blankets showed no signs of infection when encountered again later.

  During the American Revolutionary War, General George Washington heard a rumor from a sailor that British commander General William Howe had deliberately sent civilians out of Boston hoping to spread a smallpox epidemic to American lines. Washington wrote to the Continental Congress that he could "hardly give credit to" the claim. He had already inoculated his soldiers, limiting whatever damage the epidemic might have done.

• 3. Industrial-Scale Programs

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  By the time germ theory had taken hold around 1900, biological sabotage acquired scientific precision. During World War I, German agents conducted anthrax and glanders attacks against cavalry horses belonging to American and French forces, against sheep in Romania, and against livestock in Argentina intended to supply the Entente. One named participant was Anton Dilger. Germany itself was not spared: French operatives in Switzerland infected horses bound for Germany with Burkholderia.

  World War II transformed these scattered operations into government-funded industrial programs. In Britain, the Ministry of Supply established a biological warfare program at Porton Down under microbiologist Paul Fildes, with active support from Winston Churchill. Researchers there successfully weaponized tularemia, anthrax, brucellosis, and botulinum toxin. Gruinard Island off Scotland was contaminated with anthrax during a series of field tests whose effects persisted for 56 years.

  The United States entered the field in 1942, setting up a research and industrial complex at Fort Detrick, Maryland, under George W. Merck. Weapons were tested at the Dugway Proving Grounds in Utah. Facilities capable of mass-producing anthrax spores, brucellosis agents, and botulinum toxin came online, though the war ended before they saw significant operational use.

  The most brutal program was Japan's Unit 731, based at Pingfang in Manchuria and commanded by Lieutenant General Shiro Ishii. Researchers conducted often fatal experiments on prisoners and produced weapons for actual combat deployment. In 1940, the Japanese Army Air Force dropped ceramic bombs filled with plague-carrying fleas on Ningbo. During the Zhejiang-Jiangxi Campaign in 1942, around 1,700 Japanese troops died out of roughly 10,000 who fell ill after their own biological attack rebounded on their forces. Up to 200,000 people may have died from Japanese biological weapons operations overall. In the final months of the war, Japan planned to carry plague to US civilians in San Diego under an operation called Cherry Blossoms at Night, set to launch on the 22nd of September 1945. Japan's surrender on the 15th of August 1945 made the plan moot.

• 4. Cold War and Soviet Expansion

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  Nixon's decision in 1969 to unilaterally end the offensive US biological weapons program shifted momentum toward diplomacy. Negotiations ran from 1969 to 1972 at the United Nations' Conference of the Committee on Disarmament in Geneva. Those talks produced the Biological Weapons Convention, opened for signature on the 10th of April 1972 and entering into force on the 26th of March 1975 after ratification by 22 states. As of March 2021, 183 states had become party to it, making it the first multilateral disarmament treaty to ban an entire category of weapons of mass destruction.

  The Soviet Union signed and ratified the treaty. It also secretly expanded one of the largest offensive biological weapons programs in history, housed under a nominally civilian institution called Biopreparat. The scale became clear in 1979 when an anthrax leak at a military facility in Sverdlovsk killed approximately 65 to 100 people. Sheep became ill with anthrax as far as 200 kilometers from the release point. The city is now called Yekaterinburg, and parts of the facility remain off-limits to visitors.

  Biopreparat's network included facilities across the Soviet Union: a weaponized plague center at the Institute of Ultra Pure Biochemical Preparations in Leningrad, a weaponized smallpox center called VECTOR in Novosibirsk, and a weaponized anthrax production center at Military Compound 19 in Sverdlovsk itself. In the 1980s, the Soviet Ministry of Agriculture developed variants of foot-and-mouth disease and rinderpest for cattle, African swine fever for pigs, and psittacosis for chickens, under a secret program code-named "Ecology."

• 5. Terrorism and the DIY Threat

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  The cost of a biological weapon capable of producing comparable mass casualties to a conventional weapon has been estimated at roughly 0.05 percent of the conventional weapon's cost per square kilometer of effect. That economic reality is part of what makes these weapons attractive beyond state actors.

  In 2002, when material from Al-Qaeda was reviewed, analysts found planning for ricin and cyanide attacks through a loose network of cells that had infiltrated Turkey, Italy, Spain, France, and other countries.

  A newer concern is the widening access to gene-editing techniques. A method called Clustered, Regularly Interspaced, Short Palindromic Repeat technology, known as CRISPR-Cas9, has become cheap and widely available enough that scientists worry amateurs could begin experimenting with it. Unlike older techniques that might take months or years to alter a gene sequence, CRISPR compresses that timeline to weeks. Do-it-yourself biology organizations have drawn particular scrutiny because an individual researcher with no institutional oversight could theoretically attempt to build dangerous agents.

  The deliberate laboratory synthesis of the Horsepox virus from commercially acquired DNA segments demonstrated what is now possible with poxviruses. That experiment showed that highly complex viruses could be engineered from purchased genetic material, which lowers the barrier to entry for acquiring dangerous pathogens considerably. In 2015, the Blue-Ribbon Study Panel on Biodefense published a National Blueprint for Biodefense to address the expanding threat. A separate annual report from the Federal Select Agent Program described 233 potential exposures of select biological agents outside primary containment barriers in the United States alone.

• 6. Detection and Defense

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  Bacillus anthracis illustrates the medical reality defenders face. A pulmonary anthrax infection begins with symptoms resembling influenza, then progresses to a lethal hemorrhagic condition within 3-7 days, with an untreated fatality rate of 90 percent or higher. The incubation period for humans has been estimated at approximately 11.8 to 12.1 days. Models suggest that if antibiotic treatment begins within 24-36 hours of an attack, more than 80 percent of an exposed population can receive prophylaxis before becoming symptomatic, avoiding the worst mortality.

  Field detection tools have advanced to try to close that window. Researchers at the Lawrence Livermore National Laboratory have developed a device using a sandwich immunoassay in which fluorescent dye-labeled antibodies targeting specific pathogens are attached to silver and gold nanowires. In the Netherlands, the company TNO designed a system called Bioaerosol Single Particle Recognition eQuipment, or BiosparQ, for integration into that country's national bioweapon response plan. Researchers at Ben Gurion University in Israel are developing a device called the BioPen, a lab-in-a-pen tool using fiber optics and an adaptation of the ELISA immunological technique, capable of detecting known biological agents in under 20 minutes.

  Epidemiological surveillance provides an earlier warning layer. Unusual disease presentations, outbreaks among animals preceding human illness, simultaneous clusters appearing in non-contiguous geographic areas, and disease in populations or age groups for whom the illness is atypical all serve as warning indicators. During the first Gulf War, the United Nations activated a biological and chemical response team called Task Force Scorpio to respond to any potential use of weapons of mass destruction against civilians. Surveillance systems linking human clinicians and veterinarians remain the first practical defense against an attack that may not be recognized until days after it begins.