First, just an aside: I was stationed at Fort Myer when these events (probably) took place, but not in the Third Herd, as we affectionately called the Third Infantry, but in Headquarters Company, US Army, meaning most of us worked in the Five-Sided Building on the other side of the Cemetery. I say "probably" because there doesn't seem to be any markers as to the exact dates of the film's events, especially when seeing the accessorized Class C's (fatigues) they all wore which are anachronistic hodgepodges.
But the most important thing that this movie shows us today is that there were no "lessons learned." We have young men, and women, willing to be put in harms way in order to "protect our freedoms," even though the idea that Saddam or Chairman Ho was really going to attack the US seems remote. We have career servicemen who realize that, right or wrong, it's only through wars is there any sure path to advancement. And of course, there will always be veterans, and their organizations, who will support the wars because they feel that that is the only way to "support the troops."
Conversely, there will be outspoken critics who openly question these overseas excursions, and they will painted as cowards, if they are draft-age males, or turncoats, if they are seasoned veterans, but mostly just unpatriotic or even a dupe of the Commies, or Mullahs, or whoever the boogieman of the era happened to be. But the most hurtful, yet ironic, stigma is that these people wished to harm the servicemen, which is almost universally furthest from the truth.
This film shows that some things rarely change.
"...there doesn't seem to be any markers as to the exact dates of the film's events..."
Not exact, but I think it was supposed to depict events between 1968 - 69. There was at least one year card shown.