disclaimer: it's been a very long time since I've read this.

I normally like this sort of book, as I am happy to read about the dark side of history that often gets covered up, but I found it just awful, honestly. It had a very negative take on America in World War II that, frankly, just does not strike me as deserved, and I actually remember I gave it up in sheer disgust at around that point. America has committed many atrocities, but (reluctantly!) going into the war against Hitler who was literately committing genocide is definitely not one of them, and certainly not an act of imperialism when we were attacked by Japan first and decided to defend ourselves!
The bomb was regrettable, but very understandable why people would worry Japan wanted to fight to the last and be motivated to drop it: if you've ever read ANY shonen work of fiction from Japan, you kinda get the vibe that fighting to the very last is a huge fucking part of their culture. There is some confusion over whether Japan might have really wanted to surrender, but only a very biased author would prevent this as a sure thing.

This book is just completely determined to present America as imperialistic - which it often is - even in scenarios where this presentation makes no fucking sense.