Full Metal Jacket is a war movie with questions of Kubrick in the mind to the meaning and purpose of war. In this tragicomic story, one finds himself asking the question "why the hell are we fighting for?" In the following of the movie, you see how the soldiers are dehumanized and empty-brained. The movie can be thought as two parts, in the first part a group of new recruits, right before being sent to the Vietnam War, are (so-called) disciplined in a training camp and taught how to obey to their superior ("-Sir, yes sir!") by a psychologically-sick instructor and also how to talk with their rifles.
editor’s note: Stanley Kubrick is famous by his perfectionist style of shooting each scene in a pure care until he gets what he photographically wants. As far as I know, in Eyes Wide Shut, he shot a scene 127 times until he sees what he wants.