What war is the setting for the novel "All Quiet on the Western Front"?

"All Quiet on the Western Front" is a novel by Erich Maria Remarque, a German veteran of World War I. The book describes the German soldiers' extreme physical and mental stress during the war, and the detachment from civilian life felt by many of these soldiers upon returning home from the front.

The book tells the story of Paul Baumer, a German soldier who—urged on by his school teacher—joins the German army shortly after the start of World War I. His class was "scattered over the platoons among Frisian fishermen, peasants, and labourers." Baumer arrives at the Western Front with his friends and schoolmates (Leer, Müller, Kropp and a number of other characters). There they meet Stanislaus Katczinsky, an older soldier, nicknamed Kat, who becomes Paul's mentor. While fighting at the front, Baumer and his comrades have to engage in frequent battles and endure the treacherous and filthy conditions of trench warfare.

In 1930, the book was adapted as an Academy-Award-winning film of the same name, directed by Lewis Milestone. It was adapted again in 1979 by Delbert Mann, this time as a television film starring Richard Thomas and Ernest Borgnine. From November 10 to December 9, 1928, All Quiet on the Western Front was published in serial form in a German magazine. It was released in book form the following year to smashing success, selling one and a half million copies that same year.