1885, Barillet-Lagargousse , La guerre finale, histoire fantastique 

Barillet-Lagargousse (1885) La guerre finale, histoire fantastique par Barillet-Lagargousse, ingénieur destructeur, membre de plusieurs sociétés philanthropiques et savantes.

Barillet-Lagargousse’s The Final War (1885), takes the European arms race of the late 19th century to its logical end: a terrifying deadlock due to the political and social paralysis caused by weapons sufficiently powerful to be seemingly unbeatable. Based on a then-new idea, The Final War is the first elaborate extrapolation of the strangely modern notion is that peace can only be achieved through ultimate war, and the first novel to flesh it out with abundant detail. [Publisher’s Description of English translation by Brian Stableford (2014) The Final War]

Full text (French) at http://gallica.bnf.fr/ark:/12148/bpt6k58190712/f5.image