Donald McClarey from The American Catholic provides the following links for more research into the debate here and here and here. I can understand the viewpoints of both sides. I understand, and partially hold to, the idea that there is something inherently wrong with sneaking in and dropping a single weapon that will instantly vaporize tens of thousands of innocent men, women and children.
I also realize, however, that this was the end of a long, brutal, horrifying war that had slaughtered that same group of people by the tens of millions. In terms of proportionality, that means something. The links are good because they remind us there is more to the history than we sometimes hear. Like just taking Eisenhower at his word devoid of context or his own particular track record. Especially if those making the arguments are doing so because they have ideological axes to grind.
In the case of most of the history I read that is just basic, here's-what-happened history, the most they'll typically say is that we might have been able to hold out and who knows what would have happened, and it was a terrible thing to see done, but based on what they knew then it was understandable and it did help end the horrible conflict.
Again, I can sympathize with both sides, and the worst I'll say is that if America stands accused, then it does so with hands across the water, joining with the rest of the industrialized world that was every bit as guilty for the mushroom clouds over Hiroshima and Nagasaki. And that's the worst I'll say. On some days, I might even say something else.