In Liam O'Flaherty's 1923 story, "The Sniper," tragedy befalls a young soldier fighting during the Irish Civil War. Having successfully killed one of the enemy, he looks at the corpse and discovers that it was his own brother. In an instant, the futility of war is made clear. Along with other literary devices, O'Flaherty uses metaphor to drive home this point.
Monsters and Clouds
When his protagonist encounters the enemy's armored car, O'Flaherty writes, "His bullets would never pierce the steel that covered the gray monster." In this metaphor, the car becomes a gray monster. It is likely that O'Flaherty used this metaphor to emphasize the monstrous nature of war. Later in the story, he notes, "The cloud of fear scattered from his mind," after the soldier succeeds in destroying his enemy. Here, fear takes on life as a cloud that can occupy the mind.
Metaphor vs. Simile
Metaphor turns an idea into something else, rather than simply comparing it to something else. O'Flaherty writes, "Machine guns and rifles broke the silence of the night spasmodically, like dogs barking on lone farms." Here, the guns are like dogs, but are not implied to be dogs. Metaphor can have more of an impact. In the case of the soldier's fear, it not only is like a cloud but has become a cloud.