“Shall We All Commit Suicide?” Sir Winston S Churchill ominously warned in his 1924 essay about the alarming progress of biological warfare (BW), where engineered diseases could target humans, animals and agriculture. He wrote, “A study of Disease—of Pestilences, methodically prepared and deliberately launched upon man and beast—is certainly being pursued in the laboratories of more than one great country. Blight to destroy crops, Anthrax to slay horses and cattle, Plague to poison not armies only but whole districts—such are the lines along which military science is remorselessly advancing.” A century ago, Churchill predicted the risks of bioterrorism, foreseeing military strategies using engineered bioweapons that could devastate humanity and ecosystems.

In an op-ed for Business Insider in 2017, Microsoft founder and billionaire philanthropist Bill Gates warned “Infectious virus is a greater risk to humanity than nuclear war. Whether such an outbreak occurs due to a quirk of nature or is deliberately released by a terrorist, epidemiologists say a fast-moving airborne pathogen could kill more than 30m people in less than a year.” Gates emphasized the cataclysmic gravity of BW agents, indicating bioterrorism—the deliberate release of natural or engineered biological agents to harm humans, animals, or environments for terrorist purposes—could become one of humanity’s greatest perils.

Historical perspective

BW dates back to the 6th century BCE when the Assyrians poisoned enemy wells with ergot fungus, causing delusions, cardiovascular issues and death, and has since been a strategic tool in military conflicts. In the 4th century BCE, Scythian archers dipped arrows in animal feces to induce infections, while in 204 BCE, Hannibal used venomous snake-filled clay pots against Pergamene ships. In 1346, the Tatars catapulted plague-infected corpses into Kaffa, contributing to Black Death’s spread across Europe, which killed up to 200m people in the 14th century alone, wiping out nearly half of Europe's population.

During the 16th century, Spanish conquistadors used smallpox-infected blankets to devastate indigenous South American populations. The industrial revolution advanced microbiology, inadvertently enabling the weaponization of pathogens. During World War I, Germany allegedly infected enemy livestock with anthrax.

During World War II, Japan’s Units 731 and 100 weaponized pathogens like B anthrax, Yersinia pestis, V cholera and Shigella in ceramic bombs, dispersing them over Chinese cities via aerosols and testing them on prisoners, causing epidemics and an estimated 10,000 prisoners’ deaths.

The Cold War saw further advancements, with the United States and the Soviet Union developing extensive bioweapons programs.

Despite the 1972 Biological and Toxin Weapons Convention banning bioweapon development, production, and storage, signed by most UN countries, the enduring threat of bioterrorism remains alarming.

Modern bioterrorism

In 1984, the Rajneeshee sect conducted the first known US bioterror attack, contaminating salad bars in The Dalles, Oregon, with Salmonella typhimurium, infecting 751 and hospitalizing 45.

The 2001 US anthrax attacks, where letters containing B anthracis spores were mailed to media and government offices, caused 22 infections, five fatalities and required 30,000 people to undergo antibiotic treatment. The attack fueled widespread fear, prompted biosecurity policy reforms and incurred over $1bn in response costs, highlighting bioterrorism’s social, economic and global security impact.

The US Centers for Disease Control and Prevention classifies biological agents into three categories A, B, and C based on their threat level to public health and national security. Category A agents represent the highest threat due to their high transmissibility, mortality and societal impact, include B. anthracis, Francisella tularensis, Y. pestis, botulinum toxin, smallpox and hemorrhagic fever viruses (Ebola, Marburg).

Category B agents pose a moderate threat, with lower mortality but significant health implications, requiring enhanced diagnostic and surveillance, include Brucella, Clostridium epsilon toxin, Salmonella, Escherichia coli O157:H7, Shigella, Ricin toxin and V cholera.

Viruses are now considered the greatest biothreat in the EU’s expanded list including emerging and re-emerging pathogens—SARS, MERS, WestNile, Mpox and influenza A (H5, H7).

Advancements in biotechnology, CRISPR gene editing and gain-of-function research have reduced barriers to developing bioweapons, raising concerns about non-state actors misusing engineered pathogens or chimera with enhanced virulence or drug resistance. Unlike conventional weapons, BW agents remain silent, invisible and capable of widespread devastation, underscoring the urgency for global biodefense measures.

Biodefense

Biosecurity measures are vital for protecting biological research and mitigating bioterrorism risks. Early detection remains a challenge, as pathogens can spread undetected before symptoms manifest, complicating containment efforts. The Covid-19 pandemic exposed critical gaps in global biodefense, emphasizing the necessity for enhanced surveillance, rapid-response systems and international cooperation. A 2021 Lancet article by Long and Marzi reveals the global biodefense market at $12.2bn in 2019, projected to reach $19.8bn by 2027, growing at a 5.8 percent annual rate.

Strict biosecurity protocols regulate pathogen access, laboratory safety and dual-use research, but inconsistent enforcement and weak compliance mechanisms in many nations create vulnerabilities that could be exploited. A unified global biosecurity framework is essential to ensure scientific advancements benefit humanity, not destruction.

The Biological Weapons Convention prohibits the development, production, acquisition, transfer, stockpiling and use of biological and toxin weapons, yet its enforcement remains inadequate.

Geopolitical tensions complicate biosecurity by fueling mistrust and obstructing global cooperation. Scientific and political debates over SARS-CoV-2’s origins underscore concerns about laboratory safety and accidental pathogen leaks, and the need for stringent oversight in high-containment laboratories.

Safeguarding public health, Nepal’s three-tier health system must enhance surveillance, regulate biotechnology and enforce ethical research standards. Additionally, the Nepali Army and security agencies should develop robust capabilities to detect, prevent and respond to potential bioterrorism threats or bioweapons. This requires coordinated efforts in intelligence gathering, rapid response mechanisms and cross-sectoral collaboration to mitigate hazards and ensure national biosecurity.

Lessons from past pandemics and bioterrorism incidents must inform future biodefense strategies. As Churchill and Gates forewarned, bioterrorism remains an alarming threat. A failure to act now could lead to consequences far more catastrophic than any seen before.