I did a book report on this in 9th grade in Germany. I was fascinated by how Jules Verne painted the French guy in exaggeratedly positive and the German guy in negative terms. Even for highly self-critical Germans the caricature in this book is a bit much, not one of his best.
I disagree; it was remarkably prophetic regarding the character of the German leadership and public sentiment in Germany in the early 20th century, being written in 1879. The German protagonist founds a militaristic dictatorship, develops poison gas and super cannons, speaks of the superiority of the Saxon over the [racially] inferior, democratic French. It perfectly captures what became of Germany in the first half of the 20th century, down to the obsession with steel and super weapons (thinking of Hart wie Kruppstahl).
The French character isn't as developed as the German from what I remember.
> It is noteworthy as the first published book in which Verne was cautionary, and somewhat pessimistic about the development of science and technology.
The only other book in which Verne was similarly pessimistic that I'm aware of is 'Paris in the Twentieth Century', which was originally considered too negative for publication.
The Franco-Prussian/Franco-German war ended about eight years earlier, in which France lost territory to Germany (Alsace-Lorraine). Germany was very much ascendant at the time, unified and having recently besieged Paris itself, so that's not exactly a crystal-ball prediction Verne was making.
It doesn't really matter how they had acquired it, they could draw on resources and manpower - Indian regiments, Malayan rubber, Indonesian oil (via the Dutch government in exile)...
I'm convinced by reading "Britain's War Machine" by David Edgerton that Britain's darkest hour was not Dunkirk but Japan's entry into the war and its lightning capture of most of SE Asia.