Following is the latest blogpost analysis on the threat of bioterrorism with a historical perspective of bioweapons used by extremist groups, individuals, and states. The previous update, which provides a broad overview of that threat, can be read here.

Due to the growing concern that terrorists will gain access to a biological weapon, highlighted by the current COVID-19 crisis, it is important to better understand the historical development and past use of biological weapons. During the past century, more than 500 million people died due to infectious disease. Several tens of thousands of these deaths were due to the deliberate release of pathogens or biological toxins, mainly by the Japanese during WWII. To be able to better address potential bioterror threats as well as evaluate the current capacity of extremist organizations, it is crucial to assess past developments in order to better prepare for the future.

While recent technological advances in bioengineering have arguably changed the landscape of the threat, a historical perspective on the subject may still shed light on knowledge gaps in our defense system and guide our counterterrorism response. The importance of the history of bioterrorism is threefold. First, notable successful disseminations of biological agents by extremist groups can highlight the means of acquisition and reach of these types of attacks. Next, investigating the use of bioweapons by states in the past may also prove insightful. Even weapons held by legitimate governments are at risk of proliferating and may find their way into the hands of terrorist organizations if appropriate safeguards do not exist or are not stringently deployed. Therefore, critically evaluating the effectiveness of and compliance with international treaties established in order to control biological weapons can help mitigate the danger of state sponsored terrorism through biological weapons.

Historical examples demonstrate the relative ease with which determined individuals or organized groups can obtain dangerous biological agents. In late September 1984, a religious sect known as the Rajneeshee cult, which ran a hospital on its ground in Oregon, tried to poison the local community by infecting salad bars with salmonella in the largest act of bioterrorism in the United States. The cult obtained the bacteria from a commercial supplier and deliberately infected the population in an attempt to suppress voter turnout. Another religious sect in Japan, the Aum Shinrikyo cult, which famously released Sarin gas in the Tokyo subway in 1995 killing 13 people, also tried to distribute anthrax in the city several times but with no success. In addition, cult members had attempted to acquire Ebola virus from Zaire in 1992. The still unidentified perpetrators of the 2001 ‘Amerithrax’ attacks were more successful. Their spore-laced letters killed five people and launched an age of antibiotic overuse, with more than 32,000 people taking antibiotics after possible exposure to anthrax.  In a similar attempt, in early 2004 a far-right extremist, working as a laboratory technician attempted to obtain a sample of the plague bacterium from the American Tissue Culture Collection. His attempt was only detected after inquiring why the procedure was taking so long.

Today, we are witnessing renewed interest in biological warfare and bioweapons owing to several factors, including the discovery that Iraq has been developing biological weapons. According to U.S. intelligence, South Africa, Israel, Iraq, and several other countries have or are still developing biological weapons. During WWII, the Japanese launched a large scale bioweapons program, which they used for multiple large scale attacks, most notably as part of their conquest of China. These attacks included dropping ceramic bombs containing plague infected fleas on Ningbo and poisoning more than 1,000 water wells in Chinese villages, creating cholera and typhus outbreaks that had long lasting impacts even after the Japanese surrendered. The Soviets also launched a gigantic biowarfare program called Biopreparant under which they worked on various pathogens including hemorrhagic fevers, some of the deadliest viruses known to mankind. The United States started their biological weapons program on a small scale in 1941 but then ramped up their efforts during the war, mainly to prepare for a potential attack by the Japanese. Various documents seem to demonstrate that the United States also discussed the offensive use of biological anti-crop weapons.

Two international treaties outlawed biological weapons in 1925 and 1972, but they have largely failed to stop countries from conducting offensive weapons research and large-scale production of biological weapons. Biological warfare has been renounced by 140 nations, primarily for strategic and other pragmatic reasons. International diplomatic efforts, including the 1972 Biological Weapons Convention, have not been entirely effective in preventing the enhancement and proliferation of offensive biological warfare programs. The Soviet project, that was developed after signing the treaty, shows that international treaties are only a weak defense mechanism unless an effective verification procedure is in place.

It is likely that biological weapons will continue to pose a significant threat in the future. Lessons learned from the past weaponization of pathogens, however, may help prevent these weapons landing in the hands of extremists. Primary prevention rests on creating a strong global norm that rejects development of such weapons. From a historical perspective, it seems clear that there is still much work to be done to ensure that countries comply with existing treaties and thus further reduce the risk of terrorist organizations acquiring biological weapons either directly or indirectly from state facilities.