Look! They foil each other!

Awww, I was hoping for a happy ending. Oh well, life goes on! At the beginning of the chapter, Mark Fossie and the girl he shipped in to be on the base with him, Mary Anne, was the All American girl every man on the base wish he could have dated. However, as the chapter progresses, she slowly "lets herself go" and becomes "one of the boys." As this happens, Mark kind of questions who she is and why he brought her here in the first place. In other words, they become foils to each other (a.k.a foil characters as it says on the sheet provided). After thinking about how/why this happened, the only conclusion I could come to was- this only elicits the vulnerability and unpredictability of war. I think that up until this point in the book we are under the impression that war can only change those men who are in direct combat with the enemy. But by foiling these two people in the story, O'Brien is able to show that war does terrible things to those who aren't even in direct contact with it.