The Threat of Biological Weapons: From Historical Use to Modern-Day Prohibitions

Biological weapons represent one of humanity’s most disturbing creations. Unlike conventional arms, these weapons harness the power of disease itself to harm, kill, or incapacitate. From ancient armies catapulting plague-ridden corpses over city walls to modern laboratories engineering antibiotic-resistant pathogens, the history of biological warfare reveals a persistent threat that has evolved alongside scientific advancement. Today, the international community faces the challenge of preventing these weapons through the Biological Weapons Convention, while confronting new risks posed by rapid biotechnology developments.

Early attempts at biological warfare 🔗

The use of biological agents in warfare predates modern science by centuries. Historical records indicate that the Hittites released infected animals along enemy trade routes around 1320 BC, spreading tularemia among their adversaries. During medieval sieges, armies launched animal carcasses and human corpses over fortifications, hoping to spread disease among defenders. The 1346 siege of Caffa stands out in historical accounts, where Mongol forces allegedly catapulted plague-infected bodies into the besieged city, potentially contributing to the Black Death’s spread across Europe.

These early tactics relied on crude understanding of disease transmission. Without knowledge of germs or viruses, combatants simply observed that contaminated materials could sicken enemies. The practice remained sporadic and unpredictable, dependent more on fortune than design.

Modern biological weapons programs 🔗

The twentieth century transformed biological warfare from primitive tactics into systematic weapons development. Advances in microbiology enabled scientists to identify, cultivate, and weaponize specific pathogens. During World War II, Japan’s Unit 731 dispersed pathogens throughout China, using plague, cholera, typhoid, and anthrax primarily through air-dropped bomblets containing infected fleas. These actions resulted in thousands of deaths and involved forced human experimentation on civilians and prisoners of war.

The Soviet Biopreparat program 🔗

The most extensive biological weapons program emerged in the Soviet Union under an organization called Biopreparat. Created in 1974, this ostensibly civilian pharmaceutical enterprise concealed a massive offensive weapons program. Biopreparat employed 30,000 to 40,000 people across dozens of research institutes, production facilities, and testing sites throughout the Soviet Union.

Soviet scientists weaponized anthrax, smallpox, plague, and other deadly agents. They developed delivery systems capable of dispersing these pathogens over vast areas through ballistic missiles and aircraft. Perhaps most concerning, Soviet researchers applied genetic engineering to create antibiotic-resistant strains and pathogens with entirely new properties. The program continued secretly even after the Soviet Union signed the Biological Weapons Convention in 1972, representing a clear treaty violation that persisted until at least 1992.

The scope of Soviet violations only became clear through defectors. Vladimir Pasechnik and Ken Alibek, both senior scientists within Biopreparat, revealed the program’s extent to Western intelligence agencies in the early 1990s. Their accounts exposed facilities that could produce tons of weaponized anthrax and laboratories developing genetically modified pathogens resistant to multiple antibiotics.

The Biological Weapons Convention 🔗

Growing international concern about biological warfare led to the 1972 Biological and Toxin Weapons Convention. Opening for signature on April 10, 1972, and entering into force on March 26, 1975, the BWC became the first multilateral treaty to ban an entire category of weapons of mass destruction.

The Convention prohibits states from developing, producing, stockpiling, acquiring, or retaining biological agents and toxins in types and quantities beyond peaceful purposes. It also bans weapons, equipment, and delivery systems designed to use such agents for hostile purposes. Currently, 189 states are party to the treaty, with four additional states having signed but not ratified it.

Key provisions and obligations 🔗

Article I forms the Convention’s core, requiring states to never develop, produce, stockpile, or acquire biological weapons under any circumstances. Article II mandates destruction of existing biological weapons within nine months of the treaty’s entry into force. Article IV requires states to implement national legislation prohibiting and preventing biological weapons activities within their territories.

The Convention also addresses compliance concerns. Article V establishes procedures for bilateral and multilateral consultation to resolve questions about treaty implementation. Article VI permits states to lodge complaints with the United Nations Security Council if they believe another member is violating the Convention, though this mechanism has been invoked only once.

Challenges to effective implementation 🔗

Despite its ambitious scope, the BWC faces significant implementation challenges. Unlike the Chemical Weapons Convention or nuclear nonproliferation treaties, the BWC lacks both a verification system and a dedicated international organization to support its implementation. This absence severely limits the international community’s ability to detect and respond to violations.

The verification problem 🔗

Efforts to establish a verification protocol began in the 1990s. From 1995 to 2001, an Ad Hoc Group worked on drafting a protocol that would include mandatory declarations of dual-use facilities, routine site visits, and challenge inspections of suspected violations. However, these negotiations collapsed in 2001 when the United States rejected the draft protocol, citing concerns about protecting proprietary information and national security.

The dual-use nature of biological research poses unique verification challenges. Many activities crucial to producing biological weapons are inherently dual-use, making it difficult to distinguish legitimate biodefense research from offensive weapons development. Pharmaceutical factories, vaccine production facilities, and university laboratories all work with dangerous pathogens for peaceful purposes, using equipment and techniques identical to those required for weapons production.

Currently, the BWC relies primarily on confidence-building measures, voluntary annual reports where states declare certain biological activities and facilities. However, participation rates remain slightly above 50 percent, and many reports lack detail necessary for meaningful compliance assessment.

Limited resources and institutional support 🔗

The BWC Implementation Support Unit operates with just four staff members and an annual budget of approximately $2.1 million. This stands in stark contrast to verification bodies for other weapons treaties. The Organisation for the Prohibition of Chemical Weapons, for instance, had a 2025 budget of roughly $94 million. Such limited resources severely constrain the BWC’s ability to support states in implementing treaty obligations, conducting outreach, or developing compliance mechanisms.

Biotechnology advances and emerging threats 🔗

Rapid advances in biotechnology create both opportunities and risks for the BWC framework. Synthetic biology, gene editing technologies like CRISPR, and artificial intelligence convergence with biological sciences have revolutionized research capabilities. These developments enable unprecedented medical breakthroughs but also lower barriers to creating dangerous biological agents.

Scientists can now synthesize viral genomes from scratch, modify existing pathogens to evade immune responses or resist treatments, and design entirely novel organisms. The dispersed nature of these capabilities presents new challenges. Unlike nuclear weapons, which require rare materials and enormous infrastructure, biological research occurs in thousands of academic, government, and private laboratories worldwide.

Strengthening the convention 🔗

In December 2022, states parties established a Working Group on strengthening the Convention to address compliance, verification, and other implementation issues. This represents a significant opportunity to modernize the treaty framework after decades of stagnation on verification matters.

Experts propose several potential improvements. These include enhancing confidence-building measures to capture more detailed information, establishing peer review mechanisms for national implementation, developing scientific advisory capabilities to monitor technological developments, and exploring how new technologies like artificial intelligence might support compliance monitoring without compromising legitimate research.

Some suggest incremental approaches that build on existing mechanisms rather than attempting comprehensive verification systems. For instance, improving transparency around high-containment laboratories, strengthening investigation procedures for suspected violations, and creating technical capacity to assess complex compliance questions could increase confidence in treaty compliance without requiring intrusive inspections.

The path forward 🔗

The threat posed by biological weapons remains real and evolving. Historical violations by the Soviet Union and Iraq demonstrate that states will pursue these weapons despite international prohibitions. Meanwhile, technological advances continue to expand both the number of actors capable of developing biological weapons and the potential sophistication of such weapons.

The international community must balance competing priorities: preventing weapons development while enabling beneficial biological research, protecting national security and proprietary information while ensuring transparency, and managing scarce resources effectively. Success will require sustained political commitment, adequate funding for implementation mechanisms, and creative approaches to verification challenges unique to the biological domain.

The BWC has established a strong global norm against biological weapons, with near-universal membership. However, norms alone prove insufficient without mechanisms to detect and respond to violations. As biotechnology capabilities continue to proliferate and geopolitical tensions persist, strengthening the Convention’s implementation framework becomes increasingly urgent.

What do you think? How can the international community effectively verify compliance with biological weapons prohibitions while protecting legitimate scientific research? What role should emerging technologies play in strengthening treaty implementation?

References

1. https://disarmament.unoda.org/en/our-work/weapons-mass-destruction/biological-weapons/biological-weapons-convention
2. https://www.discovermagazine.com/the-sciences/ancient-empires-used-bioweapons-to-strike-terror-more-than-3-000-years-ago
3. https://wwwnc.cdc.gov/eid/article/8/9/01-0536_article
4. https://en.wikipedia.org/wiki/History_of_biological_warfare
5. https://en.wikipedia.org/wiki/Biopreparat
6. https://en.wikipedia.org/wiki/Soviet_biological_weapons_program
7. https://www.armscontrol.org/factsheets/biological-weapons-convention-bwc-glance-0
8. https://en.wikipedia.org/wiki/Biological_Weapons_Convention
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC10541916/
10. https://thebulletin.org/2024/03/how-the-biological-weapons-convention-could-verify-treaty-compliance/