What is the main conflict in A Soldier of the Great War by Mark Helprin?

This is essentially an episodic novel. It is the story of the life of Alessandro Giuliani, a Roman intellectual who fights in World War I for Italy although his natural tendency leans toward pacifism. The story is related in both monologue and dialogue as Alessandro hikes with Nicolo Sambucca, an earnest but simple laborer who prods Alessandro into telling him the story of his life as they travel over the Alps toward Rome. Alessandro is shot at, taken prisoner, and eventually released during the war. As he endures these dangers and hardships, the reader sees him growing spiritually and maturing as a man.