“The Sniper” is a story about the Irish Civil War by Liam O’Flaherty. The basic situation and rising action of the story shows a young sniper on a rooftop trying to outmaneuver another sniper on a nearby rooftop. As usual, in the rising action the main character struggles to solve a problem that intensifies and/or changes. In this story, the main character is wounded by the enemy and has to come up with a plan to defeat him.
The climax to the story occurs when the main character tricks the enemy into exposing himself and is able to shoot him dead. At this point, the main character has resolved his primary conflict. To the reader, the significant part of the story seems to be over. However, the writer has a surprise in mind for the reader at the end of the story. In the falling action, which occurs between the climax and the resolution, writers usually show the effect of the climax on the main character. In this story, the main character suddenly, and perhaps surprisingly, suffers remorse over his killing of the enemy. This prepares the reader for the bigger surprise to follow.
Resolutions often provide an ironic twist—something that is surprising or unexpected. In this case, after killing the enemy, the main character leaves the roof and climbs down to the street to look at who he has killed. When he turns over the dead body, he sees that he has killed his brother. This event underscores the nature of civil war—we often have to fight our neighbors or even our own family members.
The climax of the story is when the Republican sniper hit the opposing sniper on the opposite rooftop and killed him. He was overjoyed to have made his shot because the two had been waiting to outsmart the other and make the kill. The resolution came when the sniper who made his kill decided that he wanted to look into the face of the man he killed, who was on the side of the civil war that he hated. He became sick when he peered down at the man and realized that he was looking into the face of his brother!
The climax of the story is when the Republican sniper kills the enemy sniper. (same thing as clane's answer)
HOWEVER, there is no resolution in this story, because after the Republican sniper kills the enemy sniper he goes to see the identity of the enemy sniper whom he killed. When the Republican sniper discovers the enemy sniper he killed is his brother, that is not the resolution. That is called a DENOUEMENT (a surprise ending).