There are several examples of shame being a partner to the soldiers as they attempt to cope with war. For example, the men carry good luck charms or personal items in an effort to keep their connection to their real life back home. Therefore, superstition plays a role in how the men feel about being on the battlefield. In fact, it is a strong influence in the story. The items of loved ones are used as a way to shield the men from harm, instead of admitting they are afraid, which would be shamful, they cling to objects, for strength.
"Henry Dobbins, for example, the biggest man in the group, carries the M-60 machine gun, ‘‘which weighed 23 pounds unloaded, but which was almost always loaded.’’ He also ''carried his girlfriend's pantyhose wrapped around his neck as a comforter.''
At the end of the story, Lieutenant cross gets rid of all his mementos, deciding to put his daydreaming aside and concentrate on his job. He is ashamed of himself. Like the other men, Cross, had held onto to letters and pictures as a means of calming the unbridled fear that accompanies war and combat.
O'Brien has also said that shame brought him into the war. It was out of love that he didn't flee to Canada. Because of his love for his parents and family, O'Brien did not want to shame them by dodging the draft.
In the story "The Things They Carried" itself, the men feel shame on many levels. Some feel shame for the things they do - such as burning a village after Ted Lavender is shot or how they react to enemy fire by falling to the ground crying and hiding or how Lt. Jimmy Cross feels over his obsession with Martha and how it lead to Lavender's death.
Shame definitely figures into O'Brien's story/book. There is shame involved in many of the things the soldiers do, including Lt. Cross obsessing over a girl from home. Cross is obsessed with Martha, the girl he is interested in from "home" who has written him letters during his time in Vietnam. Her letters are more friendly than romantic, though, but he thinks he is in love with her. Later, however, he realizes that he has been a fool. He has focused so much on Martha that he has neglected to be a leader to his group. Once Lavender dies, Cross has an epiphany about this and realizes that he must focus his attention on his troops. He is ashamed of himself that he has wasted so much time thinking about Martha.