Perhaps the most shocking element in the whole story of Unit 731 was MacArthur’s agreement, after the Japanese surrender, to provide immunity from prosecution to all involved, including General Ishii. This deal allowed the Americans to obtain all the data they had accumulated from their experiments. Even after MacArthur had learned that Allied prisoners of war had also been killed in the tests, he ordered that all criminal investigations should cease. Soviet requests to prosecute Ishii and his staff at the Tokyo War Crimes tribunal were firmly rejected.
