Yes. I think we all already know this deep down from whenever we first learned about nuclear weapons. But you just move on with your life and try not to think about it too much. 

"Well, no more nuclear weapons have been used against another nation since WWII so they must have figured it out how not to use them and deterrence has worked!"

It's great that we have avoided it this long but basically if anyone uses one ever again there is a good chance it's lights out and curtains drawn for humanity, or at least the vast majority of humanity and civilization as we know it. No take backs, no mulligans.

I recall learning about nuclear weapons years ago and how many we have and the Soviets had and it seemed so crazy to me then. But to hear about it in the level of detail and minute to minute accounts of what would actually happen, who would be doing what, and how it all fits together, how many moving pieces there are and how many things could possibly go wrong in various ways really takes both the seriousness and the absurdity of the whole endeavor to a new level.

The account of what would happen if the diablo canyon nuclear plant was hit with a nuclear warhead makes me question my support of nuclear power. Even if the possibility of something like that is extremely remote maybe it's not worth the risk.