Is Bioterrorism More Lethal Than Conventional War?


Conventional war takes place without the use of any weapon of mass destruction such as a biological, nuclear or chemical weapon. On the other hand, bioterrorism can be defined as the use of biological warfare through the deliberate release of viruses, bacteria, germs or other agents to cause sickness or death in people, animals or plants. Conventional war uses conventional weapons made of kinetic, incendiary or explosive energy for causing widespread destruction. From past experiences, we can deduce that the use of biological warfare has advanced and has become more lethal as compared to any form of conventional war. The use of biological weapons has caused several causalities, deaths, global health terror and major economic and societal disruption. The emergence of various pathogens, such as the coronavirus, Ebola virus and poliovirus, has posed a great threat to human health at a global level. These germs or agents can be found in nature, but the interference of humans in the manipulation and distribution of such viruses can lead to a more harmful impact. In the past, various warfare and terrorist activities involved the deliberate use of biological agents for causing a widespread attack. Such attacks have been carried out by both states and non-state actors such as the Al-Qaeda[1] and the Japanese Aum Shinrikyo.


Bioterrorism involves the use of biological weapons which are one of the three categories of weapons of mass destruction. A biological weapon consists of two elements:

  • a biological agent, and
  • a means to deliver it.

As far as the biological agent is considered, in order to cause a biological attack a pathogenic organism must be obtained and developed in such a way that it multiplies and spreads by reaching and entering the body of a human being in sufficient quantities through inhaling or swallowing. By analyzing biological warfare agents through examples obtained from the United States and Soviet history, an understanding can be developed about the characteristics of specific biological agents used in bioterrorism:

  • The agent must be highly toxic or infectious.
  • It must be highly lethal.
  • It must be suitable for mass production and storage.
  • It should not lose its pathogenic ability over time.
  • It must remain stable in the environment long enough to infect humans.
  • It must have the potential to undergo various genetic engineering and weaponization processes.

Categories of Biological Agents

Public health authorities have categorized the use of biological agents into three kinds depending on the level of threat to national security:

  • Category A biological agents can cause a threat to national security since they can be transmitted from person to person and can cause high social disruption. These diseases include anthrax, plague, smallpox, Ebola, tularemia, Marburg, Lassa, and Machupo.
  • Category B biological agents are easily disseminated and include ricin toxin, Q – fever, glanders, etc.
  • Category C involves emerging disease agents that can be engineered for the purpose of mass dissemination, such as the Nipah virus.


  • Early use of biological warfare

Humans have been using infectious weapons for hundreds of years. The first use dates back to 400 BC when the Scythian archers dipped their arrows in decomposing dead bodies for the purpose of infecting them. In the 12th century, Barbarossa used the dead bodies of soldiers for poisoning wells. Such use of dead bodies to cause plague was also carried out during the siege of Kaffa and by the Russians in 1710. The plague pandemic killed 25 million people during the 14th and 15th centuries. In the 18th century, the British forces supplied blankets to native Americans which had been used by smallpox victims for the purpose of spreading the disease.

  • Use of biological warfare in the 19th and 20th centuries

During World War I, Germans had been running a severe biological warfare program under which they would ship horses and cattle infected with disease-producing bacteria including anthrax and glanders. The animals were delivered to the US and other countries. The same agents had been used for infecting Romanian sheep delivered to Russia. Moreover, Germany had also spread cholera in Italy and the plague in Russia.[2]

During World War II, several countries got involved in biological weapons programs: Canada had been involved in animal and crop diseases such as anthrax and rinderpest; the United Kingdom had also been planning anthrax, foot and mouth diseases; the Soviet Union had spread plague and typhus among thousands of people; and the US had been involved in the spread of anthrax. The number of soldiers dying of disease in war has been calculated to be much higher than them dying in combat until World War II.[3] 95% of the admissions of soldiers in US hospitals during World War II and 82% during the Korean War had been due to the incapacitation caused by diseases instead of combat actions.[4] During the Vietnam War, 56-75% of the admissions in US hospitals were due to malaria.[5]

  • Use of biological warfare after World War II

Immediately after World War II, news spread regarding the outbreak of diseases due to biological weapons.[6] The US biological warfare program expanded during the Korean War and in the late 1960s the US had developed biological arsenal that would be used to attack crops.[7]

  • Use of biological weapons after the Biological Weapons Convention

Despite the Biological Weapons Convention (BWC), the signatories have still been participating in activities amounting to a violation of the regulations laid down under the Convention. State-sponsored programs for the use of biological warfare have increased tremendously during the last 30 years. Moreover, non-state actors have also started to rely on such weapons for several terrorist and assassination attacks. In 1978, Georgi Markov had been assassinated using an umbrella-like device.[8] Ten days later, Vladimir Kostov was also reported to have been attacked by the same device. The device was made up of an exotic alloy of platinum and iridium which contained the ricin toxin.

In the 1970s, it was reported that planes and helicopters had been releasing aerosol colors known as the “yellow rain attacks” on the inhabitants of Laos and Kampuchea, causing the people to fall severely ill.[9] In 1979, the release of anthrax from a weapons facility in Sverdlovsk, USSR led to the death of 66 people. In 1984, 751 people had been infected with the salmonella agent responsible for causing food poisoning. In 1985, Iraq began its biological weapons program and started producing anthrax, botulinum toxin and aflatoxin. In 1994, a Japanese sect attempted to release anthrax from the top of buildings. In 1995, the release of sarin gas by the Japanese cult Aum Shinrikyo inside the Tokyo subway killed 13 people and caused thousands of casualties.[10]

In 2001, anthrax had been mailed to the US media and government offices. In 2002, six terrorist suspects were arrested for using their apartment as a ricin toxin laboratory. It was noted that even the minutest use of biological agents could cause mass casualties[11] as specified by the World Health Organization (WHO) in 1970 when 125,000 causalities and 95,000 fatalities had been reported due to anthrax, 125,000 casualties had been reported due to Q-fever, tularemia, and typhus, while thousands of fatalities had also been reported.


There are various international regulations under which the use of biological weapons has been prohibited. The Geneva Protocol ratified in 1925 prohibits the development, production and use of biological weapons in war.[12] The World Health Organization (WHO) identified that the use of biological warfare had been a big threat during the Vietnam War and Cold War and released a report in 1970 discussing various health aspects of biological weapons.[13] According to the updated 2004 WHO Guidance, biological weapons can cause a widespread attack through the infectivity of disease-causing micro-organisms, viruses, prions and nucleic acids.

  • Biological Weapons Convention prohibiting biological warfare

The Biological Weapons Convention 1972 is an important international agreement dealing with the reduction of the threat of biological warfare. The states which are parties to this Convention are under an obligation to not get involved in the development, production, stockpiling, acquisition and retention of biological agents or toxins.[14] Article 2 of the BWC mandates a state party to destroy all such weapons or agents in its jurisdiction, while Article 3 seeks prevention from international proliferation of biological weapons by prohibiting the transfer of any element of such weapons. Even though the BWC doesn’t explicitly prohibit the use of biological warfare, Article 1 of the Convention does implicitly include the prohibition of such weapons under any circumstances.

  • Customary nature of the prohibition of biological warfare

The prohibition of biological weapons is not just treaty-based. According to various state practices, it has become a general principle of international law to prohibit the use of biological weapons both during an international and non-international armed conflict.[15] There have also been cases where states not party to the Convention have carried out actions to the effect that biological weapons had to be prohibited.[16] Moreover, as stated by Australia in its pleadings before the International Court of Justice (ICJ), the use of biological weapons is against the “fundamental general principles of humanity”.[17]

  • General principles of international law of armed conflict on prohibition of biological warfare

The general principles of international law of armed conflict are also relevant in this matter. Biological weapons are considered to be indiscriminate in nature since they are capable of attacking a large part of the population, thus their use is prohibited under the norms of customary international law applicable in both international and non-international armed conflicts.[18] Moreover, the use of biological weapons during an armed conflict is also considered to be contrary to the principles of distinction and proportionality, since such weapons would not be able to form a distinction between civilian and military targets,[19] or ensure that the anticipated risk and loss for civilian population would be in proportion to the expected military advantage.[20] In addition, the use of biological warfare would also be a violation of the principle of neutrality, according to which the effects of the use of weapons should be limited to the belligerent states. The use of biological weapons would, however, spread various diseases everywhere, causing unnecessary suffering and injury on the frontiers of the neutral states as well. Therefore, such weapons are prohibited under customary international law.[21]


In light of the facts and figures mentioned above, it is evident that the use of biological warfare is more lethal than conventional weapons and more advanced in terms of the capability of its damage threshold. Since biological warfare is easier to conceal and hard to detect, its use is more complicated to understand and interpret as compared to conventional warfare. Due to the incubation period, the effects of the use of biological weapons are delayed and not easily detectable, thereby causing difficulty in providing protection from such weapons. These biological agents can lead to the spread of highly contagious and lethal diseases which can cause incapacitation and the death of millions of people. Non-state actors have also been resorting to the use of biological weapons to cause harm. Due to the lethal effects of these weapons, they are prohibited under international treaties, customary international norms as well as general principles of international law. The use of biological weapons by states would amount to a breach of their international obligations, which may also give rise to certain legal consequences in the form of reparations.


[1] M Leitenberg, Assessing the biological weapons and bioterrorism threat, Strategic Studies Institute, US Army War College, Carlisle, PA (2005)
[2] Stockholm International Peace Research Institute (SIPRI) The Problem of Chemical and Biological Warfare, Vol I: The Rise of CB Weapons. New York: Humanities Press; 1971.
[3] BG Withers, SC Craig “The historical impact of preventive medicine in war PW Kelly (Ed.), Textbooks of military medicine. Military preventive medicine: mobilization and deployment, Vol. 1, Borden Institute, Washington, DC (2003), pp. 21-57; A Leland, MJ Oboroceanu American war and military operations casualties: lists and statistics. CRS Report RL32492, Congressional Research Service, Washington, DC (2010) Available at: (last accessed 16 June 2014).
[4] ibid
[5] Walter Reed Army Medical Center Personal protective measures against insects and other arthropods of military significance. Armed Forces Pest Management Board—Technical Guide 36, Walter Reed Army Medical Center, Washington, DC (2002)
[6] History of biological warfare: catapults to capsomeres. Poupard JA, Miller LA Ann N Y Acad Sci. 1992 Dec 31; 666():9-20
[7] Supra Note 2
[8] US Army Medical Research Institute for Infectious Diseases. Medical Management of Biological Casualties Handbook. 4th ed. Frederick, MD: Fort Detrick; 2001
[9] Biological warfare. A historical perspective. Christopher GW, Cieslak TJ, Pavlin JA, Eitzen EM Jr JAMA. 1997 Aug 6; 278(5):412-7.
[10] Biological warfare: An emerging threat in the 21st century: 1/01. (n.d.). Stanford News.
[11] Danzig R Berkowsky PB . 1997. Why should we be concerned about biological warfare?. Journal of the American Medical Association 278: 431–432.
[12] The Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare, United Nations (1925)
[13] World Health Organization – Public health response to biological and chemical weapons—WHO guidance (2nd edn), WHO, Geneva (2004)
[14] Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction 1015 UNTS 163, UN Reg No I-14860, Art.I
[15] ICRC, Customary IHL Database,
[16] Japan, District Court of Tokyo, Shimoda case ; Colombia, Constitutional Court, Constitutional Case No. C-225/95
[17] Australia, Oral pleadings before the ICJ in the Nuclear Weapons case
[18] ICRC, Customary IHL Database,
[19] ICRC, Customary IHL Database,
[20] ICRC, Customary IHL Database,
[21] ICRC, Customary IHL Database,; Customary International Humanitarian Law – Rules (Vol.I) edited by Henckaerts, Jean-Marie; Doswald-Beck, Louise (2005), Part IV Use of Weapons, Chapter 20 General Principles on the Use of Weapons (Rules 70-71)

The views expressed in this article are those of the author and do not necessarily represent the views of or any organization with which she might be associated.

Amna Adnan Khawaja

Author: Amna Adnan Khawaja

The writer is a third year law student at NHLD, Kinnaird College for Women University. She recently took part in the 61st Philips C. Jessup International Moot Court Competition where her team qualified to represent Pakistan in the International Rounds.


Excellent article , enriched with not only historical references but also with scientific knowledge. Great indeed.

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