What are the motifs in The Sniper by Liam O'Flaherty?

The concept of survival underscores the entire story. Even before the sniper kills any of the Free State soldiers, he knows "there were enemies watching." The sniper's actions are driven by his desire for survival. He must kill anyone who has the capacity to bring about his destruction. So the soldier manning the armored tank must be taken out. Indeed, anyone who takes part in this warfare can become an enemy, even an old woman who becomes an informer with a few simple words and the point of a finger.