Modernism demanded that writers experimented in order to find new ways to express difficult new realities. Ernest Hemingway developed his own writing style to express the reality of war.
Hemingway employed a unique 'tip of the iceberg' writing style: writing and narrative is spare; there should be no superflous detail. In addition, the story's true meaning or body - like an iceberg's - lies below the surface.
Hemingway's short story 'Big Two Hearted River' Parts 1 and 2 on the surface is an account of a fishing expedition; the writing focuses on Nick Adams' preparations, the terrain he encounters. But below the surface what we have is a war story about a shell shocked veteran trying to recover.
Nick sees that his Michigan hometown, Seney, which is next to the river, has suffered a fire. He notes twice that the countryside is 'burned-over'. It is the kind of scorched landscape he would have seen during the war: he can't escape it. Fortunately, unlike Seney's 'scattered houses.... The river was there'. The story's deeper meaning is about Nick's attempt to get back to Nature to aid his recovery.
The war is not directly mentioned once in the story and yet that is what it is about; it exemplifies Hemingway's tip of the iceberg style, which was strongly influeneced by modernism.