Why were AUM Shinrikyo’s biological attacks in Japan largely unsuccessful?

The biological attacks carried out by the AUM Shinrikyo sect in Japan between 1990 and 1995 were largely unsuccessful because the group failed to master the necessary science and technology required for effective biological warfare.1

Despite this lack of technical proficiency, the sect attempted ten separate attacks—four involving anthrax and six involving botulinum toxin—targeting various locations, including a U.S. naval base at Yokosuka. The use of such agents to cause mass harm is a grave violation of fundamental ethical principles regarding the sanctity of human life and the prohibition of indiscriminate violence.1