It provides (among other things) a very simple report of just how and why the assassination of the Archduke of Austria resulted in the Great War.
Easy reading and likely it will be made into some dramatization later as Follett has a huge following and often his books are made into TV series.
Easy Question.
The Guns of August.
For me, The Zimmerman Telegram is a distant second.
1913: In Search of the World Before the Great War by Charles Emmerson.
A very informative book about critical locales around the world and their political/social situations just before WWI. A fascinating read about a time period that gets little popular discussion.
A Storm in Flanders: The Ypres Salient, 1914-1918: Tragedy and Triumph on the Western Front by Winston Groom — yes the Winston Groom who wrote Forrest Gump.
My others are already listed by others but I didn’t see that one mentioned previously. An yes, the WWI museum in Kansas City if you ever can.
While not specifically a WWI book, William Manchester’s, “The Arms of Krupp,” is a good read and gives a lot of insight into the mindset that brought about the war...
It’s pretty specific, but as a young man, I loved Eagles of the Black Cross - a book about the German pilots of WW1.
Shockingly, you’ll find the Richtofen was not the only German pilot of note.