Actually "The Guns of August" is 50 years old and missed to see the entire picture.
If someone would like to read a really good book about the subject which is published most recently and written by a master of his subject, than i can prefer only "Sleepwalkers" by Christopher Clark. The man is lecturer in Cambridge and wrote several great books in the last decade, including a history about Prussia. It is quite funny, because the man is Australian and in Germany itself, he was criticized because he saw less guilt in Germany, than we Germans after two World wars want to believe. The national guilt after this century is so deep in the heads of the Germans, that a German author could never write such a brilliant book.
Reviews and short summaries:
http://www.lrb.co.uk/v35/n23/thomas-...-foolish-thing
http://www.nytimes.com/2013/05/12/bo...1914.html?_r=0
http://www.theguardian.com/books/201...r-clark-review