Here's anothe intersting nuclear website:

children of the manhattan project

If you like good and big books which capture aspects of the nuclear issues I recommend by far at the top of the list the two books by Richard Rhodes:
1) The Making of the Atomic Bomb
2) Dark Sun

Other good books:
Now It Can Be Told by Gen. Leslie Groves
The Manhattan Project by Stephane Groueff

My take:

The use of the atomic bomb by the US on Japan ended the most costly war in history. It also created by its existence and use the notion that humankind has arrived at a stocktaking time in its existence, whether or not (major) war should be used to settle its affairs any more.

There have been no major wars since WWII and the UN has managed to stay in existence and somewhat relevant ever since.

I'm re-reading "Dark Sun" right now at the point in which, post-War, a commission of American leaders actually tried to recommend internationalizing information about nuclear science, weaponry included, in order to forestall an arms race. The idea was that openness destroyed the need for military competition and would enhance trust over time. The people on the panel inclueded Robert Oppenheimer and Dean Acheson. This proposal never made it to the UN, but the author made the interesting point that nuclear proliferation has achieved a comparable, though unstable and much more expensive, result.

Other members of this forum have correctly remembered the great fear of the cold war, that of nuclear annihilation. I submit that it takes this kind of fear to make us pause in our use of organized violence on the scale we committed and endured in World War II.

There seems to have been a pause since that time, where we may have forgotten the basic lesson of Trinity, Hiroshima, and Nagasaki, and seem willing to consider that these weapons are capable of use and that defense against these weapons may be possible.