I am an avid reader of history and have been since I learned to read. In elementary school I can remember eating lunch while reading a book about the concentration camps. The book was full of pictures and grossing out other kids.

I only mention this because of the book I am going to recommend,
Amazon.com: **** to Pay: Operation DOWNFALL and the Invasion of Japan, 1945-1947 eBook: Giangreco Giangreco: Books. The book is about the planning for the invasion of Japan.
The book has some eye opening information and is just flat out scary. The invasion would have been a blood bath that had never been seen in history. The slaughter of Allied, mostly US servicemen, Japanese service men, AND the Japanese civilian population would have been unreal. The author lists some assumptions that the Allies had about Japanese readiness that were completely wrong.
- We thought the Japanese were out of aircraft and aircraft fuel. They were not. They had months worth of fuel and planes available.
- We did not really know about the suicide boats and subs.
- The Japanese had figured out that wooden airplanes and mountains masked radar. The geographical position the Allied fleet would be put into was perfect to mask air raids.
- Very experienced combat divisions had been moved to Japan from Manchuria without the Allies noticing. The assumption was that the best Japanese divisions were in China and would stay there.
- Japanese defenses were well prepared and they knew exactly where we would land and when. This was not rocket science and it was pretty easy to figure out looking at the Allied methods, weather, and geography.
- ...
The death and destruction from suicide planes, subs and boats was going to be huge and that was before a boot touched ground.
This is not a big book but I had to put it down and stop reading for awhile. The enormity of the bloodshed that would have happened with an invasion was sobering and scary. The fission bombs on Japan saved millions of lives and allowed Japan to rebuild and recover much more quickly than if the Allies had invaded. Japan would have ceased to exist on at least two of the Home Islands. The dropping of the atomic bombs were done on cities that had not been bombed so that the affect of the new weapon could be judged. This is often mentioned. What is never mentioned is that both bombs where helping isolate and shape the battlefield for the first landing. And the poor b...ds that had to land or support the landing on the southern island of Kyushu where going to need all of the help they could get.
One of the many interesting pieces of information in the book was about blood supply. He documents the planning for blood drives which would be started before the invasion and continue during the landings to supply blood to the front. Given that the front was on the other side of the world the logistical effort to just move blood was huge. There were ships outfitted to hold nothing buy blood... There were not many, and if one ship was sunk, the number of deaths would be huge...
Ironically, Japan was starting to starve at the time of the surrender, and what stopped the starvation was the stockpiles of food that had been created for the invasion.
The Japanese thought they would loose 20 million people defeating the Allied invasion. What is not clear is if that was just civilians or civilians and soldiers. But that is the cost in blood the Japanese expected. And they did expect to win...
Anyway, this is a great book but I had to stop reading it for awhile before I finished.
The only other book I have had to stop reading, and one I have not finished, is about Mao. The Mao biography is pretty big, 3-4 inches thick, and I got about half way through before I stopped. Evil Genius is a phrase too often used. Mao was an Evil Genius. He makes ****** look like a stupid, choir boy. Mao ran circles around his Chinese opponents and played Stalin like a puppet, even though Stalin considered Mao the puppet. The guy really was an Evil Genius. He should have been killed physically, or more often politically, many times, but he always survived, and hundreds of millions of people died as a result.
Later,
Dan