Quite clearly the point of view selected by Tim O'Brien to narrate this story is the third person omniscient point of view, as we can see from the way that the narrator gives us access into the minds, feelings and emotions of every single character. This point of view is suitable for this story because of the way in which it allows the author--and us as readers--to examine the mixture of complex emotions and feelings that being in a war situation evokes in his characters. At times, we are given the feelings and emotions experienced by all the soldiers, such as in the following quote:
They imagined the muzzle against flesh. So easy: squeeze the trigger and blow away a toe. They imagined it. They imagined the quick, sweet pain, then the evacuation to Japan, then a hospital with warm beds and cute geisha nurses.
Here we see how they all dreamed of a quick escape from the horrors of war that they were all facing, and how the tempting possibility of self-mutilation would get them a ticket out of the war zone.
However, at the same time, the author zooms in on the thoughts and feelings of individual characters such as Jimmy Cross. Note the way in which he responds after Lavender's death and how he thinks about Martha now that he has burnt her letters:
She signed the letters Love, but it wasn't love, and all the fine lines and technicalities did not matter. Virginity was no longer an issue. He hated her. Yes, he did. He hated her. Love, too, but it was a hard, hating kind of love.
Note here how we are given privileged access to Jimmy's feelings and the way that his shame and guilt concerning Lavender's death has changed his emotions and feelings about Martha.
Thus it is that the point of view selected seems to be eminently suitable for what O'Brien is trying to achieve in this story as he presents us with a group of soldiers and the complex bundle of emotions, feelings, hopes and dreams that they have, some of them common to all of them and some of them unique.
I'm assuming you're referring to the short story The Things They Carried, rather than the novel. Here are a few ideas:
Ted Lavender: "But Ted Lavender, who was scared, carried 34 rounds when he was shot and killed outside Than Khe, and he went down under an exceptional burden, more than 20 pounds of ammunition, plus the flak jacket, and helmet and rations and water and toilet paper and tranquilizers and all the rest, plus the unweighted fear." (6) Highlights Lavender's incessant fear, the great weight of what the men carried, his death, and use of tranquilizers.
Kiowa: "He tried not to think about Ted Lavender, but then he was thinking how fast it was, no drama, down and dead, and how it was hard to feel anthing except surprise. It seemed unchristian. He wished he could find some great sadness, or even anger, but the emotion wasn't there and he couldn't make it happen." (18) Represents Kiowa's religious belief, the men's detachment from death, and the inability to move away from visions of death.
Lt. Cross: "He was realistic about it. There was that new hardness in his stomach. He loved her but he hated her." (24) Expresses Jimmy's undieing love for Martha along with the realization of what his obsession has led to.
Hope these get you off to a good start!