It is a shame that The Sleepwalkers looks like it will not be selected. I can see that it could provoke a spirited discussion, and about events now far enough back in history that movement to the P&R forum would not be necessary.

I've not read the book, but if the conclusion is that the assassination of of Archduke Franz Ferdinand caused that war I would certainly question it. What I have always read suggests that there were a great number of contributing factors, some going as far back as Congress of Vienna in 1815. What I have always read in the past is the assassination was the the prick in the highly pressurized vessel that led it to explode.