In the story "The Sniper," what conflicts are created by the presence of the enemy sniper?

The presence of an enemy sniper poses challenges to the success of the Republican sniper's objectives; this presence also poses a threat to his life. Ironically, though, there is also a conflict after the sniper is safe.
When the sniper tries to smoke a cigarette, a shot is fired at him. An enemy sniper on a nearby rooftop knows that he is on top of the building. Shortly after, an armored car pulls up below. The sniper knows that bullets will not permeate this vehicle. Soon, an old woman comes around the corner of a side street and approaches the armored car. As the gunner emerges from the turret, she points to where the sniper lies on the roof above them. Taking advantage of the gunner's exposure, the sniper quickly shoots his enemy before he can aim the big gun. Terrified, the old woman tries to run back to the side street, but the sniper fires at her and kills her, too.

Suddenly from the opposite roof a shot rang out and the sniper dropped his rifle with a curse. The rifle clattered to the roof. The sniper thought the noise would wake the dead. He stooped to pick the rifle up. He couldn't lift it. His forearm was dead.

The enemy sniper on the opposite rooftop has hit the Republican sniper and wounded him. The sniper is now very vulnerable because he cannot use his rifle. His only chance for survival is to kill the enemy with his revolver. Because this shot will be more difficult, the sniper devises a plan. He places his hat onto the rifle, which he stands on end. When the other sniper fires at this hat, thinking it is on the man's head, the hat falls to the street. As it does so, the wounded sniper drops his arm over the edge of the building and lets the rifle fall to the street. Fooled by the ploy, the other sniper believes that he has killed his foe; he stands up and looks across with his head "silhouetted by the Western sky." 

The distance was about fifty yards—a hard shot in the dim light, and his right arm was paining him like a thousand devils. He took steady aim....

The sniper hits his target. The dying enemy tumbles end over end to the street.
The worst conflict of all emerges in the heart of the successful sniper once he is on the street. He goes to the dead sniper, curious to see who the man was. When he rolls the body over, the sniper recognizes the face of his brother.