The most difficult biological-security problem today is not simply the existence of biological weapons. It is the speed at which biotechnology is changing while international security institutions struggle to keep pace. Advances in synthetic biology, genetic engineering, artificial intelligence and laboratory automation are creating enormous benefits for medicine, agriculture and public health. At the same time, they are expanding the range of technologies that could potentially be misused.
This is where bioterrorism presents a particularly difficult challenge. Unlike conventional terrorism, a biological attack may not be immediately recognised as an attack at all. An outbreak could initially appear to be a natural disease event, delaying attribution and response. The consequences could extend beyond casualties to public fear, economic disruption and pressure on already-stretched health systems.
The Biological Weapons Convention (BWC), opened for signature in 1972 and entering into force in 1975, remains the central international legal instrument prohibiting biological and toxin weapons. It prohibits States Parties from developing, producing, acquiring, transferring or stockpiling biological weapons. Its importance is difficult to overstate: unlike some arms-control arrangements, the BWC establishes a broad norm against an entire category of weapons. Yet the nature of the challenge has changed considerably since the Convention was negotiated.
The history of bioterrorism demonstrates both the seriousness of the threat and the practical difficulties involved in turning biological capabilities into effective weapons.
One of the most important cases was the Japanese cult Aum Shinrikyo. Before carrying out its 1995 sarin attack on the Tokyo subway, the organisation had also pursued biological weapons. Investigations later documented attempts involving anthrax and botulinum toxin. Its biological programme ultimately failed to produce the intended mass-casualty effect. A CDC investigation described an anthrax release attempt in Tokyo’s Kameido district as the first documented instance of bioterrorism involving an aerosol of Bacillus anthracis.
The lesson is important. Possessing scientific knowledge or biological material does not automatically translate into an effective biological attack. Technical, organisational and operational barriers remain significant. But those barriers should not create complacency. Aum demonstrated that a non-state organisation could devote substantial resources to acquiring biological capabilities.
The second major case is the 2001 anthrax attacks in the United States. Letters containing anthrax spores were mailed to media organisations and US senators. Between October 4 and November 20, 2001, 22 cases were identified, including 11 inhalational and 11 cutaneous cases; five people with inhalational anthrax died.
The attack exposed a different vulnerability: biological terrorism does not necessarily require a battlefield-scale operation. A relatively limited incident can generate an enormous public-health, political and psychological response. It also demonstrated the importance of laboratory capacity, epidemiological investigation, forensic science and rapid information-sharing.
These cases suggest that the greatest danger may not come from a dramatic biological attack alone. It may come from the combination of accessible biotechnology, malicious intent and weaknesses in public-health preparedness.
The BWC was designed around a world in which biological research was comparatively slow, expensive and concentrated in specialised institutions. Modern biotechnology is far more distributed. Research takes place across universities, private companies, hospitals and laboratories, while international scientific collaboration allows knowledge to move rapidly across borders.
This creates a difficult policy balance. Security measures must prevent misuse without unnecessarily restricting legitimate scientific research.
The BWC has mechanisms intended to build transparency and confidence. Its Confidence-Building Measures (CBMs), for example, ask States Parties to provide information on relevant activities and developments. UNODA states that annual CBM reports should be submitted to the BWC Implementation Support Unit by 15 April.
However, transparency remains uneven. A 2025 study examining participation in the BWC’s CBMs identified persistent gaps in reporting and explored how national capacity and other factors influence participation.
This matters because an arms-control regime cannot rely only on prohibition. It also needs mechanisms that allow States to identify suspicious developments, communicate concerns and strengthen confidence in one another.
The most difficult question for the BWC is therefore not whether biotechnology should be regulated. It is how to distinguish legitimate scientific progress from activity that creates unacceptable security risks.
Artificial intelligence adds another layer to this problem. AI can accelerate biological research, data analysis and scientific discovery. Combined with increasingly automated laboratories, it could potentially shorten parts of the research process that once required specialised expertise and substantial resources.
That does not mean that an era of easily accessible biological weapons has arrived. Such claims would exaggerate the evidence. But it does mean that traditional assumptions about who can acquire dangerous capabilities deserve renewed examination.
The BWC’s recent institutional discussions recognise this changing environment. Its Working Group on the Strengthening of the Convention has examined issues including scientific and technological developments, national implementation, international cooperation and assistance, and confidence-building. The sixth session of the Working Group took place in August 2025.
The future of biological security cannot rest on the BWC alone. National legislation, laboratory biosafety and biosecurity, disease surveillance, export controls, responsible scientific practices and international public-health cooperation all have a role.
The BWC should increasingly function as a platform connecting these different areas rather than treating disarmament and public health as separate worlds. Greater participation in CBMs would improve transparency. Stronger national contact points could improve communication during emerging crises. Scientific communities should also have a greater role in helping policymakers understand which technological developments genuinely change the security landscape.
The international community should also invest in countries with limited biological-security capacity. A pathogen does not respect national borders, and weaknesses in one country’s surveillance or laboratory system can become a problem for many others.
Bioterrorism remains a relatively rare form of terrorism, but rarity should not be confused with irrelevance. The Aum Shinrikyo experience demonstrated the ambition of a determined non-state actor, while the 2001 anthrax attacks showed how a limited biological incident could produce consequences far beyond the number of victims.
The BWC remains indispensable. The question is whether its implementation can evolve as quickly as the science surrounding it.
The objective should not be to restrict biotechnology. It should be to ensure that scientific progress does not create security vulnerabilities faster than governments can understand and manage them. In the coming years, the credibility of the BWC will depend not only on its prohibition of biological weapons, but on the international community’s ability to translate that prohibition into prevention, transparency and preparedness.
