Why does this affect whether it is a war crime or not?
Imperial Japan committed numerous war crimes, whether or not they agreed that they were war crimes at the time. By the same token anything that was done to them should not be judged by what their own standard was.
> by which standard that Imperial Japan recognized and adhered to?
Admonishment to get some damn perspective. What was done to Japan must be evaluated in the context of what Japan would have been doing to American soldiers and POWs had America been forced to invaded Japan proper. That war was non-stop war crimes from Japan. Particularly perfidy, false surrender, which would have gotten huge numbers of Japanese civilians killed in any case. Truman made the right call, for America and for Japan.
I have admitted that the Allies committed war crimes, so why aren't you satisfied? Why are you upset that I insist on pointing out that the Japanese did so as well?
If American war crimes are worth mentioning, then so are Japanese war crimes. Wanting to discuss one without the other isn't reasonable. What you are asking for is the erasure of context, and to that I say No.
Ego mostly, I guess its harder to be righteous and above others if you have some dark spot in your history. Also, some folks don't like complexity of real world so black and white is what they want, and obviously being on good side.
Imperial Japan committed numerous war crimes, whether or not they agreed that they were war crimes at the time. By the same token anything that was done to them should not be judged by what their own standard was.