I just finished reading Countdown 1945: The Extraordinary Story of the 116 Days that Changed the World by Chris Wallace, Mitch Weiss. Keep in mind the author is a rare animal; a Fox reporter who is a Democrat. I read this book in seven days; from October 28 to November 3. It was a page turner, and of course it helped that I already knew the outlines of the story. The book gave a day by day, in some case hour recount of the events. My father told me that many casualties were saved. I of course might not be here if the "bomb" had not been dropped. Interwoven were some very human stories of professional jealousy and rivalry, of a Japanese family severely impacted and other stories.
While there is not much soaring writing, two quotes from key players are in order. The first is from Jacob Beser: "I have often been asked if I had any remorse for what we did in 1945.I assure you that I have no remorse whatsoever and I will never apologize for what we did to end World War II. Humane warfare is an oxymoron. War by definition is barbaric. To try and distinguish between an acceptable method of killing and an unacceptable method is ludicrous." Paul Tibbetts, the lead pilot on the Hiroshima strike said ""If wars are going to be fought, I believe the object is to win the war.You're going to win it with all resources at your disposal. And if you're fortunate enough to possess powerful weapons or weapons more powerful than those of your enemies, there's only one thing to do and that's to use them."
You'll have to read to get more. My opinions on this subject matter are to some extent on other threads and elsewhere. Just ask.