On the Rainy River” is an exploration of the role of shame in war. The story develops the theme of embarrassment as a motivating factor, first introduced by Jimmy Cross in “The Things They Carried” and “Love.” Just as Jimmy Cross feels guilty about Ted Lavender’s death, O’Brien feels guilty about going to Vietnam against his principles. He questions his own motives, and in this story he returns to the genesis of his decision in order to examine with us the specifics of cause and effect.

Ironically, despite its specific details and its preoccupation with reality, “On the Rainy River” is the story most easily identifiable as fiction. The real Tim O’Brien did indeed struggle with his decision to heed his draft notice, but he never actually ran to the Canadian border, and he never stayed at the Tip Top Lodge. Still, as he states explicitly later in the work, the point of a story like this one is not to deliver true facts exactly as they happened but rather to use facts and details in order to give an accurate account of the feelings behind a given situation. Though the events in the story are not true, the story itself conveys an emotional truth.
By describing his personal history, O’Brien makes a broader comment on the confusion that soldiers experienced when the demands of their country and community conflicted with the demands of their princples and conscience. O’Brien’s description of his moral dilemma about going to Vietnam illustrates how the war was fought by soldiers who were often reluctant and conflicted. In the context of the collection’s later stories, “On the Rainy River” weighs the guilt of avoiding the draft against the guilt of committing atrocities against other humans. Though it seems obvious that killing is more ethically reprehensible than draft-dodging, O’Brien’s story explains how his largely uninformed community nonetheless wields a moral clout that overpowers his own opposition to the war.
This story references one of the recurring ideas in The Things They Carried: that war twists moral structures and makes it impossible to take a morally clear course of action. Joseph Heller’s World War II novel Catch- 22 also addresses the twisted morality of war by describing a situation, called a “catch-22,” in which a problem’s only solution is impossible because of some characteristic of the problem. O’Brien is trapped in a catch-22 because the only way that he can avoid guilt is by taking a course of action that will make him feel guilty. If he goes to war, he will feel guilty for ignoring his own objection to United States involvement in Vietnam, but the only way to avoid this guilt involves incurring the disapproval of his community—which will cause him to feel guilt and shame. In The Things They Carried, O’Brien shows how soldiers experience catch-22s both during the war and in the time surrounding it.
The bald, shrunken, silent Elroy Berdahl is a father figure for the narrator. Although the two do not explicitly discuss O’Brien’s dilemma, Elroy forces O’Brien to shake himself out of complacent confusion. But Berdahl’s presence isn’t sharp or invasive. Rather, his effect is that of a mirror—saying nothing, expecting nothing, perhaps not even knowing the situation at hand, he leads O’Brien to the river and forces him to confront Canada and the prospect of freedom from the draft sitting on the other side. O’Brien is compelled into action, not because Elroy forces him, but rather because the old man leads him to the river, where the necessity of making a choice once and for all becomes clear to O’Brien.
O’Brien’s narrative reveals that he feels the need to justify and explain his decision to us, his readers, by putting us in the position of ethical judges of his actions. O’Brien’s description of himself as a naïve, impressionable youth is part of a defense of himself and of his actions. Although his blunt questioning of “What would you do?” and “Would you cry, as I did?” forces us to recognize the difficulty of his position, it also invites us to evaluate the validity of his course of action. Later in the work, O’Brien illustrates the power of war to transform an individual by showing his own transformation from young and impressionable to disillusioned and uninspired. Here, he compares the act of remembering his young, naïve self to watching an old home movie, and this metaphor makes us the audience of this movie and forces us to take a more active role in considering O’Brien.