The Biological Weapons Taboo


COVID-19 has revitalized the debate on why biological weapons should not be used. International actors have expressed a new interest in the bioweapons threat — one that is focused on preventing and stigmatizing that threat as a priority concern. Biowarfare is on the global political agenda to a greater extent than it has ever been before.

This fresh interest has often centered on the biological weapons taboo. The taboo is the claim that bioweapons are so disgusting, immoral, and unacceptable that actors will not use them. The taboo has previously been dismissed as anemic and of little significance to both state and international security. The taboo was even criticized as a “potentially dangerous” way of doing arms control relating to biowarfare.

Yet the taboo is currently experiencing something of a second life in the wake of COVID-19. The pandemic has demonstrated the potential destruction of bioviolence in a whole new way. In doing so, the COVID-19 pandemic has strengthened the taboo and underpinned a renewed approach to biowarfare prevention that has the taboo at its core. This new shift in perception has significant implications not only for how we understand what actors think about bioweapons but also how we prohibit these armaments. The taboo is changing bioweapons policy in a major move further away from more traditional methods of arms control.

The Taboo

The World Health Organization defines bioweapons as “microorganisms like virus, bacteria or fungi, or toxic substances produced by living organisms that are produced and released deliberately to cause disease and death in humans, animals or plants.” Biowarfare is not an active or normalized part of state military strategies. Even when states have approved the strategic option to use biowarfare, they have rarely actually done so (aside from some limited examples such as Japan in World War II).



Some analysts explain non-use as a lack of military utility. Bioweapons are hard to make and difficult to control. Contagious agents are especially problematic in that disease can spread unintentionally and on a vast scale. The infection can rebound onto the attacker, known as the “boomerang effect.” It is also suggested that bioweapons are avoided out of a fear of like-for-like retaliation.

These explanations ignore the power of the biological weapons taboo. The taboo states that abhorrence of biowarfare shapes how humans understand and construct policy on the threat. The taboo exerts a forceful normative prohibition leading to the rejection and non-use of bioweapons. Taboos are already associated with other weapons of mass destruction including nuclear and chemical arms. The bioweapons taboo has not been analyzed in the same depth as those around the use of other weapons of mass destruction. The taboo has often been lumped together with the chemical weapons taboo — but these are very different types of weaponry and we should be more cautious about assuming that these taboos are the same.

Bioweapons are taboo in that they are potential mass killers that cause harm in disgusting ways. Al Mauroni said biowarfare is considered “a ‘dirty’ way to fight.” Disease is a repulsive threat and we fear the contamination of our bodies, especially when that contamination is deliberate. Biowarfare is not just a physical trauma but a psychological one. Bioweapons have been termed “weapons of terror” on that basis. Mahatma Gandhi famously said: “Fear of disease kills more men than disease itself.”

Biowarfare is also taboo in that this aggression seems very different to conventional violence. Bioweapons are effectively invisible (although there may be physical symptoms of disease). Disease is invasive to the body in a way that conventional armaments are not. Bodily infection also means that a target cannot escape a threat, whereas they could run away from an enemy with a gun or evacuate a burning building. The target carries their contamination around within them.

Bioweapons are taboo in that they can be contagious. Conventional weaponry cannot spread and replicate destruction as communicable infection can. Contagion connects to a further claim that biowarfare is taboo because it is indiscriminate. The claim is not flawless: Non-contagious agents (like anthrax) can be discriminate and conventional weapons can be indiscriminate — for example, landmines. Yet the perception of biowarfare as indiscriminate and immoral remains a core factor as to why these weapons are set apart as taboo.

The stigmatization of bioviolence is evident in agreements like the 1925 Geneva Protocol and the 1972 Biological Weapons Convention. The latter states in taboo-like terms that bioweapons are “repugnant to the conscience of mankind.” Officials negotiating the ban said they did so explicitly to codify the taboo. Then U.S. ambassador to the United Nations, James Leonard, said American approval of the convention was a case where the agreement would get the taboo “on the books.”

COVID-19 and the Taboo

The taboo’s strength and significance have been questioned. The Biological Weapons Convention has also been criticized for failing to fully uphold the taboo and for not establishing clear verification measures. This criticism risks overlooking how the taboo and the Biological Weapons Convention have been recognized as vital for preventing bioviolence. President Barack Obama’s 2009 National Strategy for Countering Biological Threats reaffirmed the convention’s importance and asserted that normative restraints are critical to stopping biological threats. The 2018 National Biodefense Strategy adopted a similar view and spoke of norms as a necessary means against biowarfare. 

COVID-19 has reinforced the taboo to a whole new level. While some analysts were ready to write off the taboo before the pandemic, there is now more international interest in, and commitment to, the taboo. Attention to the taboo has increased thanks to the way in which COVID-19 has effectively demonstrated what a bioweapons attack could look like. Clearly a natural outbreak is not the same as a military attack. Yet the outbreak still provides a new picture of what biowarfare can look like. A former U.S. national security advisor, John Bolton, said the pandemic was “a roadmap for the people who do control biological weapons, or aspire to biological weapons, what can happen.”

The picture isn’t pretty. COVID-19 demonstrates not only the terrible threat of disease to life but also to our way of life as seen in lockdowns and closed borders. The world has experienced extreme disease outbreaks before, such as the 2014-16 Ebola epidemic. Yet COVID-19 has really hit home the perils of disease as a weapon. Biowarfare has turned from a relatively unknown threat into something that feels more real. This new perception plays directly into taboo feelings of disgust, rejection, and the prioritization of biowarfare as a major threat.

New concern over biowarfare has often been helped along by claims that COVID-19 was the result of China’s bioweapons testing. China has claimed in response that it was the United States that brought biowarfare to Wuhan. The allegations are widely dismissed as conspiracy theory. Yet even these allegations have reinforced the connection between COVID-19 and biowarfare as a taboo act.

The taboo now plays a new and more prominent role not only in understanding why we are averse to biowarfare post-COVID-19 but how we stop the threat. The 2022 update to the National Biodefense Strategy and the 2022 National Security Strategy both prioritized the commitment to norms as a primary control against bioweapons. The updated 2023 U.K. Biological Security Strategy also refers to the need to strengthen “the global norms that underpin global non-proliferation.” The 9th Biological Weapons Convention Review Conference in 2022 highlighted the taboo as necessary for improving the convention. The taboo is now getting a lot more airtime in places where decisions are being made.


Others are less optimistic. Skeptics say that COVID-19 might increase interest in developing bioweapons leading to the taboo’s breaking. The fear is especially centered on actors who may have no commitment to the taboo, such as terrorist organizations.

The pandemic raised a concern that terrorist groups could use COVID-19 in attacks. The FBI issued a warning in March 2020 that white supremacist groups were using messenger apps to encourage members to spread the virus to Jewish people and police officers. The Council of Europe Committee on Counter-Terrorism said COVID-19 could be an inspiration to terrorists as it had revealed just how vulnerable societies are to disease. The new interest in pandemic disease as a major threat could also actually count against the taboo. The extreme media attention and fear generated by COVID-19 could be entirely what terrorists want.

Whether terrorists adhere to the same norms that restrain state actors has been questioned, including specifically in relation to weapons of mass destruction. Breaking accepted norms may comprise an intrinsic aim of terrorism itself. Terrorism can also disrupt the international expectations held by state actors. An example of this would be the way the taboo against torture has been violated in respect to the War on Terror. 

Yet there is no evidence that terrorists have engaged in mass bioviolence or that such an attack would undermine state commitments to the taboo. Even major biological threats from other states have failed to undermine the taboo in the past. The Soviet Union maintained an extensive biowarfare program called Biopreparat during the Cold War in violation of the Biological Weapons Convention. The Soviet Union publicly admitted to the program in the early 1990s. The revelation did not cause others to abandon the taboo — for example, the U.S. did not restart its biowarfare program that it renounced in 1969. Biopreparat instead encouraged greater condemnation of bioviolence and strengthened the taboo.


Biotechnology advances might alter perceptions of the taboo. Scientists have attempted to develop so-called “designer” weapons which could be biologically engineered to attack only specific targets, such as by ethnicity. If biological armaments become more destructive, more targeted, or more efficient, then this new capacity could erode the taboo. 

Biotechnology research has become even more prevalent in the COVID-19 era. There is now new investment and interest in biological research. Biological research has always been dual use — the same research to preserve health is often the same as that needed to create weapons. Could COVID-19 actually open up opportunities to build even more efficient bioweapons than ever before?

Such a view would be overly pessimistic. Biotechnology advances have often encountered significant resistance, which can be seen in the opposition to genetic engineering. COVID-19 has also constructed disease as something to be stopped and not used offensively, in line with the taboo. Changes in biotechnology will not automatically challenge the taboo and may actually engrain the taboo further.

Overall, the taboo is not a perfect restraint. It is not the case that no one has ever thought or thinks about biowarfare as a realistic option. Yet biowarfare is not an active part of military strategy and the taboo has always been a major factor as to why. The response to COVID-19 has strengthened that taboo considerably. Seeing what disease can do has made biowarfare more taboo than ever before. Using that taboo to stop biowarfare has also now become a more important and integral aspect of international strategies to prevent this terrible threat.



Dr Michelle Bentley is Reader in International Relations and Director of the Centre for International Security at Royal Holloway, University of London. This article is based on a new book: Michelle Bentley (2023) The Biological Weapons Taboo. Oxford: Oxford University Press.

Image: Morgana Wingard

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