The principal character who feels pulled in conflicting directions by his desires and obligations is the protagonist and narrator, Frederic Henry. As an American in the Italian army as an ambulance driver, Henry feels no patriotism, no desire to be a hero rewarded with medals.
Well, I knew I would not be killed. Not in this war. It did not have anything to do with me.
Still, while Henry does not feel any stirrings of the heart in his military role, he does, however, have a sense of responsibility in his role of medic. As the Italians have many casualties in the Battle of Caporetto, all the ambulances are busy. When some wounded men are put into his truck and it becomes mired in the mud, and in Chapter 29, Henry orders two sergeants to help clear the way, one of them says, "I have to go." Then, they both start down the road; Henry fires his pistol and hits one; Bonello takes Henry's gun, catches up with the other and executes him for desertion.
On the next day as they continue their retreat, they approach the border, but see that the carabinieri are apprehending men as deserters. Quickly, while they are holding others, Henry runs and dives in the water as shots follow him. In that moment his desire for Catherine surpasses any sense of duty; for, he truly loves her. His emotions are genuine for the first time in his life.