Confidence-building measure submissions under the Biological Weapons Convention from 1987 to 2020, an indicator of voluntary transparency in the regime. Image by Ego.Eudaimonia, licensed under CC BY-SA 4.0.
The Biological Weapons Convention, commonly known as the BWC, is the treaty that prohibits biological and toxin weapons. Opened for signature in 1972 and in force since 1975, it turned a humanitarian prohibition into a permanent disarmament commitment. Its core is the general-purpose criterion: biological agents, toxins, and delivery systems are lawful only when they serve peaceful, prophylactic, or protective purposes.
The political difficulty comes from biology’s dual use. Vaccines, diagnostics, disease surveillance, and pathogen research require capabilities that can also be diverted to hostile purposes. The BWC prohibited an entire category of weapons of mass destruction. Its design, however, remained lighter than the later architecture for chemical weapons: the treaty has broad normative force, while verification depends on voluntary transparency, national implementation, and continuing political negotiation.
Summary
- The BWC was the first disarmament treaty to ban an entire category of weapons of mass destruction.
- The regime’s central gap is institutional: the convention has no agency of its own for routine inspections or permanent compliance assessment.
- Confidence-building measures help reduce suspicion, although they depend on regular national submissions.
- Export controls and domestic legislation give practical effect to Articles I, III, and IV.
- The 2023-2026 meeting cycle is preparing options for the Tenth Review Conference, expected to take place by 2027.
From the Geneva Protocol to the BWC
The BWC’s direct predecessor is the 1925 Geneva Protocol. That instrument prohibited the wartime use of poison gases and bacteriological methods after the First World War. The decisive difference is that the Geneva Protocol targeted use in war. The BWC reached the weapon’s preparation cycle. That step mattered because research, production, and possession of agents could otherwise remain outside the center of the 1925 prohibition.
After the Second World War, biological and chemical weapons became part of the weapons-of-mass-destruction agenda. The United Nations General Assembly was already calling in 1946 for the elimination of atomic weapons and other means capable of mass destruction. Negotiations moved slowly because military and industrial interests remained sensitive. In the late 1960s, the separation of the chemical and biological tracks opened a path forward: the United Kingdom proposed dealing first with biological weapons, and the United States announced the unilateral end of its offensive program.
That movement made it possible to conclude the BWC in 1972. The official text, available in the UNODA treaties database, uses a broad formula. Instead of relying on a closed list of agents, the convention regulates type, quantity, and purpose: the same microorganism can be lawful in public health and unlawful inside an offensive program. That choice preserves the treaty’s ability to follow scientific change.
Core Obligations
Article I is the center of the treaty. It requires each State Party to keep biological agents and toxins only in types and quantities justified by prophylactic, protective, or other peaceful purposes. The rule also covers delivery systems designed for hostile use. The wording is deliberately technology-neutral: it covers natural, synthetic, or modified agents without depending on the method of production.
Article II turns accession into disarmament. Prohibited stockpiles must be destroyed or diverted to peaceful uses. Article III brings the prohibition into the field of nonproliferation by banning transfer and assistance to prohibited programs. The convention therefore addresses both the act and the capacity. It condemns biological weapons and tries to prevent offensive capability from forming.
Article IV carries that obligation into domestic law. Criminal statutes, laboratory rules, controls on materials, and export oversight give the BWC domestic effect. Without those measures, the prohibition would remain abstract. A state accepts the treaty internationally and must apply it to universities, companies, armed forces, public laboratories, and commercial intermediaries.
The Verification Gap
The BWC has no verification mechanism of its own. The treaty provides for consultations among States Parties and allows complaints to the Security Council, whose response depends on political decision in a body subject to veto. The result is a strong prohibition with weak oversight: the norm is clear, but no permanent technical authority can inspect, audit, and certify compliance.
The gap has both technical and political foundations. Lawful and unlawful activities can use similar equipment, civilian facilities, and ordinary scientific personnel. A fermenter or pathogen collection gains meaning through the program’s scale, secrecy, and purpose. At the same time, states with pharmaceutical or biodefense sectors fear exposing industrial secrets and national-security information. Biological verification requires enough access to generate confidence, with enough protection to preserve lawful research.
This weakness affects everyday diplomacy. A state that complies with the convention may be pressured to demonstrate the lawfulness of defensive research without disclosing sensitive details. Another state may use vague accusations to embarrass rivals. Minimal clarification mechanisms have value in their own right. They create routines of question and answer before public escalation. In a regime without inspectors, national documentation and technical channels work as political evidence of good faith.
In the 1990s, a special conference created an ad hoc group to negotiate strengthening measures. The attempt to produce a legally binding verification instrument failed at the Fifth Review Conference in 2001 and 2002. Since then, the regime has advanced through incremental tools: voluntary transparency, technical assistance, annual meetings, and debates over science and technology. The convention survived, but the distinction between legitimate biodefense and offensive preparation remains politically sensitive.
Confidence-Building Measures and Institutional Support
Confidence-building measures, known as CBMs, were agreed in 1986 and expanded in 1991. They request national information on biodefense, relevant laboratories, legislation, and unusual health events. Their function is to reduce ambiguity before suspicion becomes a diplomatic accusation. When reports arrive regularly, other governments can distinguish administrative silence, technical doubt, and a signal of risk more carefully.
The chart used as the lead image summarizes the limitation of this system. Submissions grew between 1987 and 2020, but participation remained incomplete. Transparency is uneven: states with more administrative capacity tend to report better. Resource-constrained administrations may fail because of institutional limits. In the other direction, the absence of inspection makes selective declarations easier for a government that wants to conceal prohibited activity.
The Implementation Support Unit, or ISU, was created by the Sixth Review Conference in 2006 and operates in Geneva under the United Nations Office for Disarmament Affairs. The Ninth Review Conference renewed its mandate until 2027. The ISU sustains the regime’s administration, receives CBMs, and helps with universalization, although it remains far from an inspection agency. It organizes cooperation. Decisions on noncompliance remain in the hands of states.
Exports, Sensitive Controls, and Resolution 1540
Because the BWC prohibits assistance to biological weapons, export controls became an operational complement to the treaty. The harmonized control arrangement known as the Australia Group, created in 1985 after chemical weapons were used in the Iran-Iraq War and coordinated by Australia, aligns national rules on sensitive dual-use items. The logic is to close commercial gaps between jurisdictions without turning the BWC into a trade treaty.
In the biological field, these controls cover lists of agents and equipment that could feed an offensive program. Their relationship with the BWC appears in Articles I and III: blocking a sensitive transfer helps the exporting state avoid prohibited assistance. Security Council Resolution 1540, adopted in 2004, reinforces this layer by requiring controls against non-state actors interested in weapons of mass destruction.
This instrument carries a political cost. Informal export regimes bring together specific participants, and countries outside them may view the rules as technological barriers. Biotechnology moves through synthesis services, commercial chains, and specialized personnel, which reduces the effectiveness of rigid lists. For that reason, controls preserve legitimacy only when they move alongside the peaceful cooperation required by Article X. Public health and security have to appear as compatible objectives.
Science, Biosecurity, and Dual Use
Synthetic biology has made the BWC harder to administer. Sequencing, genetic editing, and DNA synthesis accelerate vaccines, diagnostics, and outbreak surveillance. The same capabilities can increase the stability, transmissibility, or concealment of an agent used for hostile purposes. The regime’s challenge is to govern diversion, not to freeze science. The central issue becomes the combination of open research and institutional responsibility.
This agenda brings the BWC close to biosecurity. The term covers protection against accidental or deliberate exposure to dangerous agents, with rules on access, inventory, training, and transport. When these practices work, they reduce accidents and make diversion harder. Weak civilian facilities can create risk even without a state weapons program, especially when they handle high-consequence pathogens.
Scientific cooperation under Article X has to be read together with that responsibility. Developing countries have a legitimate interest in laboratory capacity, health surveillance, and pharmaceutical production. Assistance programs should include regulatory training and a culture of security. A balanced solution rejects two simplifications: treating all advanced biotechnology as a military threat, or treating peaceful access as activity without safeguards.
For countries with limited biological capacity, oversight competes with basic laboratory-safety needs. Safe laboratories, disease surveillance, and transport rules reduce internal risks and strengthen the convention from below. When national implementation improves, the regime gains less through punishment than through predictability. That logic helps explain the emphasis on assistance and cooperation in recent meetings.
Historical Cases and Compliance Concerns
Historical examples explain why verification matters so much. Before the BWC, imperial Japan used biological weapons and carried out human experiments in Manchuria, especially through Unit 731. After the convention entered into force, the Soviet program known as Biopreparat became the classic example of institutional risk. It showed that a prohibited capability could be hidden inside formally civilian scientific and industrial structures.
Today, compliance concerns appear in national reports, diplomatic accusations, and disputes over biodefense. United States reports cite assessments about Russia, China, North Korea, and Iran. Those assessments are the position of a specific government, and the BWC lacks a verification authority that could turn them into a technical decision of the regime. The consequence is political: suspicion quickly enters rivalry among states when there is no investigation accepted by all sides.
Ambiguity also affects outbreaks and accidents. An unusual disease can come from a natural event, a biosecurity failure, a laboratory accident, or deliberate release. Each hypothesis requires its own investigation. Political rivalries, military secrecy, and lack of access to the site can distort the response. The BWC adds a disarmament question to health work: if hostile use or prohibited development occurred, what evidence supports that conclusion?
The Review Process and the 2023-2026 Debate
The Review Conference is the BWC’s main political moment. Article XII provides for periodic assessments of the treaty’s operation. The Ninth Review Conference, concluded in 2022, maintained annual meetings between 2023 and 2026, renewed the ISU until 2027, and created a working group on strengthening the convention. That group concentrates the debate that will lead to the Tenth Review Conference, expected to take place by 2027.
The Brazilian chairmanship of the working group, assumed by Ambassador Frederico Duque Estrada Meyer in 2024, gives the subject direct relevance for Brazil’s diplomacy. Brazil’s position usually combines disarmament, nonproliferation, and peaceful access to technology. In the BWC, that means supporting greater confidence without turning biotechnology into the privilege of a few countries. A regime without reliable means of assessment remains vulnerable. A regime perceived as discriminatory loses legitimacy.
The cycle through 2027 will test whether States Parties can turn consensus into instruments. Improving CBMs, expanding assistance, and strengthening the ISU are likely to face less resistance. Any mechanism close to inspection or international compliance assessment will be more sensitive. The real controversy is the degree of transparency states will accept when laboratories, national defense, and the biotechnology industry occupy the same space.
Political Meaning of the Convention
The BWC establishes a clear normative line: disease, toxins, and biological capabilities must stay out of war. That line makes it possible to demand national legislation, organize assistance, justify export controls, and treat suspected use as an international-security problem. Even with limited institutions, the convention gives states a common legal language for condemning offensive programs and guiding biosecurity policies.
The regime shows a recurring feature of contemporary disarmament. Prohibiting a weapon differs from building the infrastructure that makes the prohibition verifiable. The Chemical Weapons Convention created a specialized organization for chemical weapons. The BWC remained supported by national commitments and diplomatic processes. Its future will depend on the ability to bring norm and institution closer together: preserving peaceful scientific cooperation and giving the regime more reliable means to detect, investigate, and respond to violations.