Naah, they don't even say the US are monsters in this one, in fact the crew (well most of it anyway) were getting ready to prevent Nagasaki after what they've heard happened on Hiroshima.
While this isn't a propaganda movie, it's still packed with surprises.
Such as one of the crew member getting ready to commit the act of high treason.
Besides, when Hiroshima happened, Japan was already down and out, even they admitted it, especially in the Imperial Japanese Navy, their entire fleet had been sunk.
And their entire Air Forces sounded like amateurs compared to what the US had.