I initially posted a version of this question in /r/asksocialscience but didn't get much response.

I'm looking for some historical perspective to help make sense of [this letter from the APA] (http://www.theguardian.com/world/interactive/2014/jan/22/american-psychological-association-leso-letter).

Are there other cases of medical professionals/psychologists who participated in what a reasonable person would describe as a war crime who 1) were "just following orders" and/or 2) expressed some reservations about what they were doing?