Pretty good book on the US regime of secrecy around nuclear weapons—from its unofficial birth before the Manhattan project to the eventual loosening of restrictions around the end of the Cold War. And for a book dealing with stuff that's inherently Restricted Data, it does a pretty thorough (and engaging) job!

One thing I would have liked to see was treatment of how the same wartime focus on secrecy bled over into other areas and continued into the Cold War, but that would have probably blown up the topic beyond a single book.