here's where my japan scholarship comes in
dower's embracing defeat explicitly notes that us officials knew japan was ready to capitulate. as an island, japan needed colonies for raw material for the war effort.
by the time you fight japan back to the japanese islands they have no raw material
Thing is, he's right about intent from a legal perspective, he'll just stick his tongue out and put his fingers in his ears if you try to show him any of the mountain of evidence of intent, or the fact that the International Criminal Court and most other nations disagree.
That's the harder genocide to prove... which is why there's another one that looks at effect.
And its not like war crimes can't/arent/weren't part of genocides