It is fairly easy to see how honor and tradition influence action in Faulkner's "A Rose for Emily." For example, it is often argued that Emily acts to buy rat poison as a defense of her honor to either punish Homer or to prevent him from leaving her. The family honor might be said to be preserved by her action. Similarly, tradition might be said to influence the actions and choices of the town council in relation to Emily's taxes. After being thwarted by Emily's staunch insistence, they are forced to give in and yield to the tradition that Colonel Sartoris cancelled her taxes in perpetuity.
Miss Emily had been a tradition ...from that day ... when Colonel Sartoris ...remitted her taxes, ... from the death of her father on into perpetuity.
It is harder to see honor and tradition at work in "How to Tell a True War story" because, for one thing, the story is predicated on the premise that one can never tell what is true in a true war story, even though it is insisted upon from the outset that everything is true.
In war you lose your sense of the definite, hence your sense of truth itself, and therefore it’s safe to say that in a true war story, nothing is ever absolutely true.
In a real sense, Rat's letter praising his buddy is an act of honor but, in keeping with the ambiguity of the story, his honorable act turns to shame as the sister never writes back. In a similar vein, tradition might be seen in the act of writing this same letter as it is traditional for someone to write a letter to the family. If though, this is cast in the light of tradition, ambiguity once again divests it of its power because O'Brien asserts that the tradition of goodness in war is only a "very old and terrible lie."
if you feel that some small bit of rectitude has been salvaged from the larger waste, then you have been made the victim of a very old and terrible lie.