Perry struggles to understand what he is doing in Vietnam.what does he finally decide about his purpose there?

Perry grapples with this question:

You talk about Communists—stuff like that—and it doesn’t mean much when you’re in school. Then when you get over here the only thing they’re talking about is keeping your ass in one piece” (Fallen Angels, p. 149). After killing the Viet Cong soldier in the village, Perry continues to lament the reasons he is in Vietnam to his brother Kenny: “I just told him that the war was about us killing people and about people killing us, and I couldn’t see much more to it .... I had thought that this war was right, but it was only right from a distance .... But when the killing started, there was no right or wrong except in the way you did your job, except in the way that you were part of the killing” (Fallen Angels, pp. 269-70).