That Man Abbott

Paul Burns: If more people knew about Unit 731, I doubt there'd be as much support for the "Japan was just minding its' own business when America dropped atom bombs on it for no reason" attitude.

RDQ,
America did not drop the atom bomb on Japan for no reason. Had the US and its allies gone on to invade the Japanese homeland the Allied death toll would have been in the millions and the war probably would not have finished unti aboiut 1951. (One estimate I read in WW2 documents said 1954, IIRC,.)
Also, there was the question of realpolitick. Stalin had just declared war on Japan and was poised to invade and occupy northern Japan. (Russia and Japan were traditional enemies). Truman was also determined to prevent this.
Truman knew exactly what an atom bomb would do to a Japanese city which is why he took the more or less untouched city of Kyoto, a Japanese cultural treasure, off the target list the military provided him.

A visit to the Hiroshima and the Nagasaki atomic bomb museums would surprise many: the Japanese were - and still are - quite proud of being a country united in time of war and of each and every citizen striving to support their country's war effort.    That pride is quite separate from the hurt they suffered - and still suffer - from the utterly devastating bombs that were dropped on them.     By the way, the Japanese scientist knew damned well within 48 hours what type of weapon had been dropped on them! -so much for the myth that didn't have a clue until well after the surrender.

731 Unit?   The appalling and unnecessarily cruel things the Imperial Japanese did there "for scientific purposes" were no such thing.   The ONLY redeeming feature of the whole sickening sadism at 731 was that it tied up some resources and technical personnel that might have been used to help the Imperial Japanese war effort elsewhere

@ Paul Burns;

It wasn't Truman who ordered Kyoto to be spared the atomic bomb. It was his War Minister, Henry L. Stimson, for the reason that Stimson had spent his honeymoon in Kyoto.

@RDQ et.al.;

Unit 731's personnel were granted immunity from prosecution for war crimes because the US regarded the findings of their research to be too important militarily to risk it being tendered in evidence at a trial. In short, the US were beginning to fight the Cold War, and didn't want the Soviets to gain access to Unit 731's files on Biological Warfare.

You are right Terangaree. However, the Soviet Union and the Communists in China did gather one heck of a lot of intelligence on just about everything that went on in Unit 731; they had ready access to a lot of surviving victims and others with direct knowledge of this aspect or that.
I think all the false propaganda about the Americans using germ warfare in the Korean War was based on information the Communist regimes had gleaned about Unit 731's crimes against humanity.