us with all details. On the other hand, the members of the General Staff, comparable to our own OPD, were opposed to giving the information.
To summarize, Naitō stated that the Japanese army had an organization for BW, both defensive and offensive. The offensive operations were under ‘Second Section of War Operation’ under the General Staff. The research and defensive work was under the Bureau of Medical Affairs and known as ‘Section of Sanitation’. Three organizations figured prominently in the actual work. Foremost of these was the installation at Harbin, Manchuria, under the jurisdiction of the Kwantung Army. The other two were under the China Army in Nanking and at the Army Medical College here in Tokyo.
The main research work at Harbin was under the direction of Lt. Gen. Shirō Ishii and apparently was conducted between the years 1936 and 1945 (there is some likelihood that Ishii will be apprehended shortly).
Colonel Naitō stated that the reason for planning offensive research was because the Japs expected that Soviet Russia might attack Japan with BW, especially in Manchuria. He states that there was some BW sabotage (inoculating horses with anthrax) in the northern part of Manchuria during 1944 or 1945 while the Japs were building the Peiangcheng-Heiho railroad. Further, he stated that Japan should be prepared for revenge in case the enemy used illegal warfare.
Naitō advised that the Emperor did not like the preparation for chemical warfare by the Japanese army or navy. Because of this the scale of research for chemical warfare was not permitted to be large. Since the General Staff was cognizant of the Emperor’s feeling on chemical warfare they insisted that the work on biological warfare should not refer to offensive preparations. They therefore referred to all work on BW as being purely defensive.
Naitō stated that General Headquarters made no attempt to begin active BW and did not plan to unless the enemy initiated this type of warfare. As an afterthought he stated that the circumstances during the last period of the war became such that the Japs were unable to start BW.
The following agents were listed by Naitō as having been studied: Plague, cholera, dysentery, salmonellas and anthrax. He stated that none of the filterable viruses were studied because of, ‘the difficulty to get them in mass’!
Colonel Naitō fears that all the experimental records at Harbin may have been burnt at the beginning of Russia’s sudden invasion. He stated, however, that if we succeed in securing one of the key personnel of the Harbin installation, it should be possible to obtain information concerning the work carried on there.
The following studies were made by the Army Medical College in Tokyo:
a) Studies on cheopis flea, zoological studies for the purpose of defense and tests of insecticides.
b) Studies on mass production of bacteria, in connection with possible sudden large-scale demands for immunizing agents to combat large cholera or plague epidemics.
c) Studies on some poisons which are hard to detect, for instance ‘fugu’ toxin.
d) Studies on keeping bacteria in a living state by the lyophile process.
Comment: I asked Naitō whether prisoners were ever used as experimental ‘guinea pigs’. Naitō ‘vows’ that this was never done.
Finally, it is gratifying to note, as you will see in my report, that our intelligence on Jap BW activities collected during the war was accurate insofar as the defensive organization was concerned.
I now plan to return to the United States and I look forward to seeing you again on your next visit to Camp Detrick.
Sincerely, Lt. Col. Murray Thompson.
DOCUMENT INSERT, ATTACHED TO LETTER:
SECRET
REPORT
OF
SCIENTIFIC INTELLIGENCE SURVEY IN JAPAN
September and October 1945
VOLUME V
BIOLOGICAL WARFARE (BW)
TABLE OF CONTENTS
SUMMARY OF FINDINGS
CONCLUSIONS
SUMMARY: BIOLOGICAL WARFARE (BW)
Responsible officers of both the army and navy have freely admitted to an interest in defensive BW.
Naval officers maintain that offensive BW was not investigated.
Information has been obtained that from 1936 to 1945 the Japanese army fostered offensive BW, probably on a large scale. This was apparently done without the knowledge (and possibly contrary to the wishes) of the Emperor. If this was the case, reluctance to give information relative to offensive BW is partially explained.
BW seems to have been largely a military activity, with civilian talent excluded in all but minor roles.
The initial stimulus for Japanese participation in BW seems to have been twofold:
a) The influence of Lt. Gen. Shirō Ishii.
b) The conviction that the Russians had practiced BW in Manchuria in 1935, and that they might use it again (the Chinese were similarly accused).
The principal BW center was situated in Pingfan, near Harbin, Manchuria. This was