The Center for a New American Security offers this detailed case study of Aum Shinrikyo. "Sixteen years ago, a Japanese apocalyptic cult, Aum Shinrikyo, dispersed sarin, a chemical weapon, in the Tokyo subway system, killing 13 people and prompting 6,000 others to seek hospital treatment."
Aum Shinrikyo: Insights into How Terrorists Develop Biological and Chemical Weapons puts forward several lessons to better understand attempts by other terrorist groups that acquire chemical or biological weapons.
A summary of observations of the Aum Shinrikyo (Aum) case include:
"1. Aum’s biological program was a failure, while its chemical program was even more capable than would have been evident from its successful release of sarin in the Tokyo subway system in 1995."
"2. Effectively disseminating biological and chemical agents was challenging for Aum."
"3. Accidents recurred in Aum’s chemical and biological programs but did not deter pursuit of these weapons."
"4. When Aum’s top members transitioned to using violence, they readily brought other leaders down this path and effectively persuaded, isolated or killed dissidents."
"5. Though police pursuit of Aum was remarkably lax, even intermittent or anticipated enforcement actions highly disrupted the cult’s efforts to develop chemical and biological weapons."
"6. The key work on Aum’s biological and chemical programs was conducted largely by the leadership group."
"7. Aum’s hierarchical structure facilitated initiating and resourcing biological and chemical programs."
"8. Even a retrospective assessment of biological and chemical weapons programs like this one is difficult and burdened with gaps and uncertainties."
"9. Aum displayed impressive persistence and produced successes despite its commitment to many bizarre ideas, its misallocation of resources and its numerous operational failures."
"10. Significant failures preceded or accompanied Aum successes."
How Do Terrorists Develop Biological and Chemical Weapons?