Where would we be without Chris Taylor? He's pretty much the only way we can make sense of all the crazy violence, chaos, and pain that makes its way across the screen over the course of Platoon.
See, the movie is is as much about the Vietnam War as it is about Chris Taylor's emotional journey—one in which his soul, to paraphrase Rhah, becomes the battleground for two opposing forces: Sergeant Barnes and Sergeant Elias, his two military-spiritual "fathers."
While it becomes clear as the film progresses that Taylor is definitely in the Elias camp, so to speak, Barnes leaves a lasting impression on him, and even his final act in Vietnam (the killing of Barnes) is a very Barnes-esque move (Barnes earlier kills Elias). Taylor is a complicated fellow, and in order to understand his complexities we have to chart his development.
At First, He's Young and Naïve…
Taylor arrives in Vietnam at the beginning of the film, and he's about as green as they come: fresh, clean, and completely unaware of the horrors that await him. He really has no idea what he's doing, and we see that during his first patrol. While walking point, he passes out, then has a run-in with some ants, and finally is taken off point because he stinks so bad at it. He exclaims, "A gook could be standing 3 feet in front of me and I wouldn't even know it." During his first night patrol, he falls asleep, and upon waking he is unable to set off his Claymore because he forgets to turn the safety off.
Poor Chris Taylor, he's so young and inexperienced for the first quarter of the film, it's a wonder he makes it through at all.
… But He Joined the War for Honorable Reasons…
While working latrine duty with King and Crawford, he talks about why he joined the army in the first place: "I figured why should just the poor kids go off to war, and the rich kids always get away with it?" King, who's sharing latrine duty with him at that point, jokingly brands him a "crusader," the same word Barnes uses to describe Elias.
Now, even though Taylor is in Vietnam because of some crusade he's waging against a corrupt American political-cultural system, he's not totally naïve. His reasons for signing up aren't bad reasons, but by the end of the film he'll no longer believe really in anything that has to do with Vietnam. Even though Taylor's reasons are noble, there's a little more to the story.
He's Also Got Some Family Issues…
Taylor's only real blood relationship is to his grandmother. When he's narrating, he's usually writing letters to her. He never writes home to mom and dad, and he even says things that suggest he may have a less than stellar relationship with them: "Of course mom and dad didn't want me to come here. They wanted me to be just like them. Respectable, hard-working… they drove me crazy with their goddamned world." Then there's the letter he concludes by saying, "Tell mom and dad I… well, just tell them." In some ways, Chris Taylor wants to live a life that is the exact opposite of what his parents want for him, and what they have. This, too, motivated his decision to join the army.
... And Eventually He Gets Fed Up With the War…
Like everybody else in the film, and like just about everybody else who fought in Vietnam, Taylor get sick of the whole thing. This is nowhere more evident than during the village scene, where he almost loses it and starts firing his gun near the feet of a one-legged villager, yelling at him, "Dance motherf***er dance!" Taylor is on the edge, and he says as much in one of his letters to his grandmother: "Day by day, I struggle to maintain not only my strength, but my sanity. It's all a blur. I have no energy to write. I don't know what's right and what's wrong anymore."
Despite the fact that Taylor starts to feel his moral compass go awry, he still manages, like Elias, to preserve some degree of right and wrong. When he catches some of the soldiers raping a Vietnamese villager, he breaks up the party and reprimands them: "She's a f***ing human being man, f*** you… f***ing animal… all of you are f***ing animals." Later, he even admits that he's made a mistake by coming to Vietnam, and that he feels like he can't get out of the hole. One of the consequences of that mistake is that he starts to do things he would never have dreamed of.
… And Finally, He Becomes Like Barnes.
Okay so Taylor doesn't kill a good, innocent soldier like Elias (that's what Barnes does), he doesn't commit rape (the other soldiers do that), or kill any innocent civilians (again, Barnes). This is all true. But after he realizes that Barnes has killed Elias and suggests that the guys "frag" him, then we know he's become a hardened veteran, one with his illusions destroyed. The Chris Taylor who came to Vietnam with a strict moral compass is gone.
The best indication of Taylor's metamorphosis into a Vietnam-infected soldier willing to do unspeakable things is his final deed in the war: the killing of Barnes. Barnes was ready to kill Taylor before the air strike knocked them both unconscious, and while we expect Taylor to let it go, so to speak, we also understand how he arrives at his decision. Barnes is as good as dead anyway—well, there's some debate there—but still, the very fact that Taylor is willing to use an NVA gun to do the deed suggests that this a deliberate act of revenge—for Elias' death, for Barnes' killing of a potentially innocent woman, and for his general attitude throughout the film.
In some ways, we get why Taylor does it, but we're also sad that even this most pure of characters—the one who volunteered for the war for noble reasons, the one who is trying to do his service for his country, the one who tries his hardest to stay above the fray, the pollution, the horrors to which the others succumb—is now tainted. He admits as much in the film's final narration, describing himself as the child of two fathers, Barnes and Elias. They, and the war, will "always be there," sort of the like The Force, but a little more tragic.