舊日軍731部隊

Recently the Mainichi News reported the following:

　第二次世界大戦後の占領下で、米軍が「細菌戦」などを研究した旧日本軍７３１部隊の関係者１２人の郵便物を検閲するよう指示していたことが分かった。山本武利・早稲田大教授（メディア史）が国立国会図書館の米公文書資料から、検閲指示の秘密文書を発見した。米軍は人体実験などのデータ提供と引き換えに、同部隊員らの戦犯訴追を免除した。その一方で、郵便検閲により関係者の動向を探っていた事実が明らかになったのは初めて。謎の多い部隊をめぐる情報収集に、米側が戦後、硬軟両様の手段を駆使していた事実が浮かび上がった。
　文書は１９４６年２月１５日付で米陸軍参謀第２部（Ｇ２）から、連合国軍総司令部（ＧＨＱ）の民間検閲局（ＣＣＤ）あてに出された１枚。上下に「機密」のスタンプ、右上には「廃棄」を求めた手書きのメモがある。
　内容は２項目で、最初に「下に挙げた人物の郵便物を検閲するように」と指示。７３１部隊長だった石井四郎（１８９２～１９５９年）や、石井の側近で戦後はミドリ十字を創設した内藤良一（１９０６～８２年）ら１２人の氏名をローマ字で、肩書や住所とともに列挙している。満州事変の首謀者、石原莞爾（１８８９～１９４９年）の名前もある。
　検閲のポイントは五つで、石井や細菌戦に関するあらゆる言及など。「会合の手はず」なども挙げ、関係者同士の連絡にも注意して検閲するよう求めている。
　第２の項目は、部隊の研究施設にいた「医学的な背景を持つ」とされる９人のリスト。住所は「不明」だが、これらの人物の動向にも注意するよう求めたとみられる。二つのリストとも、従来７３１部隊の関係者として知られていなかった名前が含まれている。
　米軍は占領開始直後の４５年９月から、同部隊関係者の尋問を始めたが、当初から戦犯免責をちらつかせ、情報を引き出そうとした。４７年には実験データを提供させ、関係者の訴追は見送った。今回の文書は、米軍が尋問により証言を引き出すと同時に、郵便検閲を通し、ひそかに情報を得ようとしたことを示す。
　山本教授は「東京裁判（極東国際軍事裁判）が始まる前の時期で、７３１部隊の免責に必要な作業だったのかもしれない」と話している。

It had been understood that when Japan was under the occupation of the American after World War II, the US military had directed the inspection of the mails of 12 persons who were connected to the 731 old Japanese army forces that researched on "Biological warfare". [Takeshiri] Yamamoto as the professor of Waseda University (History of Media) discovered at the National Diet Library some US official documents that allowed eyes-only inspection. The U.S. military exempted members of this force from war crime prosecutions in exchange for their offer of the data of the human experimentation. This was the first time for one side to use mail inspection to clarify facts and search for the movement of the concerned party. Through this information gathering on the force which was covered by lots of mysteries, the fact that after the war the US had been using threats and persuasion as the means had come to the surface.
It was one document dated February 15, 1946 sent from the staff office of the US Army Second Division (G2) to private inspection bureau (CCD) which was under the General Headquarters (GHQ). At the top and bottom of the document the word "Secret" was stamped. Hand-written memos that requested "Abandonment" was seen at the upper right corner.
The content had two items, first it instructed that, "The mail of the person enumerated below be inspected". Shiro Ishii (1892-1959) who was the head of 731 forces, and Ishii's aides, Ryoichi Naito (1906-82) who founded The Green Cross after the war were enumerated, in all 12 names were enumerated in Roman alphabet order with title and address. There was also the name Ishihara (1889-1949) who was the master-mind of the Manchurian Incident.
There were five points for the inspection, all were related to Ishii and the biological warfare. It requested to note, to inspect and to report "Arrangement of the meeting" etc. on people that communicated with this group.
Item two was a list of nine people related to research facilities of the Japanese force who "had medical background". Because their addresses were "unknown", it requested that these people's movement be noted. The list included two names previously not known to be connected to the 731 forces.
The U.S. military immediately after the occupation in September, 1945 tried to start questioning the persons related to this force, and to pull up information, amid the possibility of granting war crime immunity. The experimental data was offered in 1947, and prosecutions on the concerned parties were put off. This document showed that the US military tried to obtain information secretly through mail inspections and at the same time tried to draw out the testimony by questioning.
Prof. Yamamoto was speaking that "Probably the work on the immunity of 731 forces must be done at a time before the start of the Tokyo War Crimes Tribunal (Far Eastern international, military trial) ".

The finding of Professor Yamamoto adds one more piece of evidence to support the belief held by Chinese historians that the US granted immunity to the 731 forces in order to obtain the experimental information.