In "How to Tell a True War Story," the narrator reflects on everything that war can be. Well aware that he is contradicting himself, O'Brien uses paradox to capture his conflicted relationship with war and his participation in it.
A little after the story's halfway point, he elaborates on his paradoxical feelings about the war:
War is hell, but that’s not the half of it, because war is also mystery and terror and adventure and courage and discovery and holiness and pity and despair and longing and love. War is nasty; war is fun. War is thrilling; war is drudgery. War makes you a man; war makes you dead. The truths are contradictory. It can be argued, for instance, that war is grotesque. But in truth war is also beauty. For all its horror, you can’t help but gape at the awful majesty of combat.
Placing all of these characteristics side by side, O'Brien knowingly paints a contradictory picture of his stance on war. In a single sentence, he states that it is both thrilling and drudgery. War is not majestic despite being horrific—part of its majesty lies in its horror. These contradictions speak to what sparks O'Brien's project in writing The Things They Carried and other books. It is because he does not have one single, stable narrative about the war that he's able to keep writing his war stories. He'll never be able to boil his feelings about the war down into a single conclusion and will therefore always have more to say.
Another paradox he brings up alongside these paradoxes is that war makes one feel alive because it brings one so close to death:
At its core, perhaps, war is just another name for death, and yet any soldier will tell you, if he tells the truth, that proximity to death brings with it a corresponding proximity to life. After a fire-fight, there is always the immense pleasure of aliveness. The trees are alive. The grass, the soil—everything. All around you things are purely living, and you among them, and the aliveness makes you tremble.
In this paragraph, O'Brien shows that life means something thanks to death, and inversely that death means something thanks to life. Similarly, he insists that witnessing and participating in the evils of war makes one "want to be a good man." By experiencing the worst of the opposite, one "want[s] justice and courtesy and human concord" more than one ever did before.