This is the mushroom cloud from the atom bomb the United States dropped on the city of Nagasaki on August 9, 1945, 64 years ago today. Three days earlier, the US had dropped a similar bomb on the city of Hiroshima. (Wikipedia has an excellent, informative piece here.) The combined death toll for these horrific weapons was somewhere between 100,000 and 200,000, if post-war cancers and other bomb-induced maladies are figured into the picture. Nobody really knows. The estimates are all over the place. Suffice to say, the populations of these unfortunate cities were basically wiped out, for all practical purposes.
To date these are the only nuclear weapons that have ever been detonated in a war. Most Americans have conveniently forgotten or filed away in some drawer never opened the recollection that this country is the only one to have ever employed these awful, inhuman weapons. I remember how causally Air Force guys would talk about using these accursed things on the communists. It was then and there, if not before, I concluded that this country had gone mad. Things have not improved since then.
What we're looking at here is the reason the Cold War never went hot. No one in their right mind would ever want a repeat of the destruction wrought on these two cities. Nuclear weapons are the ultimate terror weapon. That a weapon so indiscriminate in its destruction and lethality would actually be employed is simply beyond the imagination of any sane person. Thankfully, the leaders of the nations who possess these weapons have until now been sane.