Why western armies specifically? What countries have a history of actually holding their military to legal account for their actions?
Have you heard of Germany?
I don't think that's the example you want. Left to their own devices the Germans would not have held themselves accountable. As we speak the most popular party in Germany is a holocaust revisionist party.
Germany would never be held accountable unless defeated by the USSR.
And even so, it was still very limited responsibility.
Japan knew this one as well. Their future would have been much different if it was the USSR in charge of the pacific after the war finally ended.
The Chinese people future would be much different (the genocide would go on) if there wasn't USSR in charge in the region.
Yes, though if you are referring to the Nuremberg Trials its not a great example. A huge number of Germans were aware of, complicit in, or directly involved in genocide...the trials had 24 defendants.
Soviet army in the WWii.
How were they held accountable? Or are you referring to millions of soldiers they threw into the meat grinder or were shot BT their own officers?
There was actual law enforcement in the Soviet army.
Hence, there was no genocide of the German people (which would be a completely justified and understandable action from any Soviet soldier's point of view).
On the contrary, US military is absolutely free to violate any war rules.