I think that the story brings out what exactly is contained in the modern theatre of warfighting. What is seen in the message of the story is not the Classical, Homeric notion of warfighting. There is nothing honorable here. The elimination of targets is done under night cover and done with stealth. The target is killed from a distance. It is quick and efficient. The message of the story is that modern warfare has managed to take a dehumanizing experience (war) and add alienation to it. The sniper, himself, is emotionally estranged from what he needs to do. The sniper does not recall Republican mantras to soothe him. He does not cite his target as impeding the cause. It is a form of emotional estrangement with which the sniper proceeds in his mission. His task completed, it is only then does he fully understand the emotional implications of what he has done. This revelation is too late as he realizes that he is his brother's murderer. In the end, no amount of comfort can soothe him with such a revelation as he looks "into his brother's face."
I think that this message has applicability to modern generations to detail the human cost of war. Every person that is killed in war is someone's brother, someone's son, someone's mother, or someone's daughter. The only human affect that is really seen in the story is when the sniper confronts the face of the person he has killed. While modern advancements in war such as drone technology and "smart bombs" along with supposedly targeted procedures that ensure only "targets" are taken out have transformed war from the days of the sniper, the emotional reality is that some other human being is killed. In Classical war fighting, one looked into the eyes of the enemy they killed. There was honor in direct confrontation and one absorbed the responsibility of killing another human being. Yet, in the modern theatre of warfighting, technology has managed to distance this reality, making killing easier because one does not have to fully witness the consequences of their actions. The message of the story is applicable to future generations because no matter what, the end result of war is death. and there has to be a responsibility for this that one must absorb. The sniper does so and recognizes it far too late. It is here where both the soldiers and legislators that declare war can find the message in the story highly applicable.