>>7296079Its theme encompasses the Modern and post-Modern age: Bureaucracies are more powerful than any human could ever be, and humans, by their own error, allow bureaucracies to guide and destroy them.
The prose is novelistic and straightforward to read, which is what made it popular, but the way it addresses World War I as beginning by a series of blunders and fatalism by men unwilling to compromise is what gives it staying power. Allegedly none of the parties involved wanted a war; how did it happen? The book outlines this.
Lastly, JFK liked it, and most presidents have zero taste in books.