User blog comment:Rhialto/On 'Project Fenrir"/@comment-24918243-20140815183736/@comment-25244773-20140816161053

Oh, 731 is pure nasty evil, men doing horrible things as practice for doing even MORE horrible things on a larger scale. (For example, they worked up a theoretically practical bomb to spread bubonic plague. You can guess the research that went into that.  And who they were going to use it on.) I suspect it's a combination of lack of records, and their relative sedateness compared to the Nazi doctors, whose experiments tended towards the completely insane.