Read this. It's a very well done narrative of the history of US nuclear weapon development, from the start to the present day. There are so many near misses, so much internal bickering, that it's surprising that nothing terrible actually happened. More good luck than good management.

Don't skip the epilogue too.

It makes me happy to live in a deliberately nuclear free country. The risks are high.

I'd love to see a version of this from the Soviet perspective, but I expect it'll never happen.