The storyline is uncomplicated: president Eisenhower left office warning the USA might become a LAWCAP puppet (using Bucky's terminology) and lo and behold, that's precisely what happened.
"We" fight because the war machine has a "life" of its own. There's nothing especially American or democratic about it. It wants to spread "freedom and democracy" but, being a heartless / soulless mechanism, isn't really qualified to do so.
We've been scraping by with a phony USA for awhile now. Resurrecting a bona fide USA remains an uphill battle. Lots of heroic Americans have been fighting to bring it back.
I'm reminded of The Matrix: most people settle for the illusion, don't even suspect they've been duped, soldiers included -- although some more knowingly serve as quislings.
I'm glad this film is playing in Baghdad (so far clandestinely i.e. not yet on mainstream TV, although that's coming).
I'm glad the Iraqis are learning that the American people still fight (including with movies such as this one) to preserve a brave heritage, even though they too are a conquered people in many ways, living in an occupied land.