My opinion is U.S. has always erred on the wrong side of humanitarian considerations right from the time she actively started taking interest in world affairs. This article on the inhuman and clinical biological elimination of the Chinese, Russians and Koreans by the Japanese has this fact buried inside:

The reign of terror was the work of the notorious Unit 731, a secret arm of the Japanese army based near Harbin, north-east China, which since 1935 had combined expertise and unspeakable cruelty to develop biological weapons to help pave the Japanese army’s way into strategically important areas of south-east China.

Yet its work was to remain secret for years. The unit’s activities were referred to just once at the Tokyo war crimes trials. Rather than prosecute the unit’s senior members, the US occupation authorities in Japan granted them immunity in exchange for access to years of extensive research into biological weapons.

The perpetrators returned to Japan to lead respectable lives, occupying top positions in the pharmaceutical industry and the health ministry. Dr Masaji Kitano, who succeeded the unit’s notorious founder, Shiro Ishii, as its leader, went on to head what was once Japan’s biggest pharmaceutical firm, Green Cross, which infected 1,800 Japanese haemophiliacs with HIV through unheated blood products in the 1980s.

Sigh…