Thematically appropriate

There's a lot more to the things they carried then simply the Vietnam War. But that's my jumping off point because that's what I know I know. and now you know what I know and the suchlike...
but more to the point the Vietnam War was not the first to use propaganda but was the first to have such elaborate propaganda as Richard Nixon's strategy of simultaneously reducing troop numbers while expanding the war into Cambodia, the less than secret bombings, and other ways of distancing the war. On the other hand Walter Cronkite's reporting might not have ended the war but it did bring up the ambiguous nature of the war.
This translates into the ambiguity of "the true war story" As the author concludes on Pg 85 "You can tell a true war story if you just keep on telling it." All the finer details are up for grabs, "Adding and subtracting, making up a few things to get at the real truth." So that is one theme to consider. another potential thesis might be exploring the metaphorical and literal burden's experienced by the squad.

Defining Postmodernism

Truly a nigh impossible task as Postmodernism is partially about deconstructing definitions. If However we choose to define postmodernism as disbelief grand narratives, the use of multiple motifs from a variety of national cultures, and the entropic nature of literature then yes we are studying postmodernism as well as entering a puesdomodern era, which I think in a way is postmodern, existentialism shares a lot traits with realism namely a harsh and bleak tone in addition to denying the existence of a supreme being or show faith as irrational. in one sense puesdomodernism shares traits such as an interest in the supernatural/ fantastical IE Avatar, Star Trek, District 9, and Disney's The Pirates of the Caribbean. All four of these contain futuristic technology, magic, or some other saving throw The point being is that after the usual suspension of belief in metanarratives is followed by an intellectual withdrawal. However the use of science fiction and the use of simple moralistic tales that are earth centered and the message being one of tolerance, neither of which are bad things, but character depth would be a good thing, and deeper plot lines, (one of the above mentioned movies was visually impressive, but by way of plot was little more than Pocahontis IN SPACE). So we are seeing interesting literary times, sorta....