What is the author's style in Under Fire by Henri Barbusse?

In Under Fire: The Story of a Squad (Le Feu), Henri Barbusse speaks in the first person past tense. In the early chapters, introducing his mass of characters and setting the stage for the action of the battlefield, he stands back and only gradually becomes an active participant. This occurs when a buddy asks why he is always jotting notes. He admits that he plans to write a book about their experiences. He intends to include their own words and also "big words" that tell the truth about the war. Barbusse writes as a participant, not allowing himself to slip into omniscience. Note that he dedicates the novel "to the memory of the comrades who fell by my side at Crouÿ and on Hill 119, January, May, and September, 1915." Whether he incorporates actual comrades into the novel and/or creates fictional characters on his own is immaterial, for his object is to show that war, while waged by the masses, is oblivious to individuals and out of the control of those who suffer in the trenches. The book is published in 1917 and the graphic descriptions demonstrate that the impressions are fresh.