I just finished "The Nuclear Express", subtitled "A Political History of the Bomb and its Proliferation", by Thomas Reed and Danny Stillman. I'd ordered it a while back, then forgot about it - when it came my interest was a bit reduced. I picked it up, and after not that many pages I couldn't put it down.
In one way it one of the best kinds of history: it is written by knowledgeable people who use specifics of persons, time, and place to illustrate the points they are making. There is little fluff here - even personal opinion is labeled as such. It is fact after fact after fact, not in an unordered recitation but rather laid out to underpin the historical themes within the book.
By the end I felt somewhat fearful about the future. During the Cold War people worried about nuclear war, but I think the danger of the use of nuclear weapons is much greater now (though not, at least initially, in the context of an all-out war). I hope those responsible for relevant policy decisions read this book, including the new President.