The question of whether a biological weapon attack did, indeed, occur due to intentional deployment by human beings is an extremely difficult one to pin down. The utter ideal is to have witness testimony by the perpetrators (that, hopefully, is not coerced), other hard evidence such as communications among the perpetrators discussing how it was done, and supportive evidence via bioforensics. But this ideal is extremely rare. Particularly with historical events.
In this case, we have a situation where the testimony of the perpetrators were captured by Soviet military legal counsel as well as the Americans. The question of whether the testimony was coerced will always be there and may not ever be disentangled. Further, when one examines the testimony carefully, it is apparent that the men the Soviets captured supported, but were not directly involved in deploying plague in Ningpo, Manchuria. And the testimonies of the American missionaries discussed the impact of an epidemic of unknown (but suspected) etiology, but not the act of deploying plague.
Therefore, we present this case study with less of an emphasis on attribution and more on a focus of how the community survived the attack- without any practical access to pharmaceutical countermeasures. We propose this is the main lesson from this case study and a warning to policy makers that would attempt to over-estimate the potential impact of an act of biological terrorism on society. Biological terrorism and warfare are important threats to our society. However appropriate contextualization of human response behavior is crucial when assessing these threats in contemporary society.