So the main point of Avatar in your opinion -- the reason it was explicitly made -- is that the military sucks? Not colonization or overcoming physical adversity or even just a fun sci-fi romp? It was just $100 million of "lol the army sucks?"
And you realize that a movie about the horrors of the Vietnam War isn't necessarily anti-military, right? America lost tens of thousands of young men and hundreds of thousands more were injured -- the country was torn about the war, with people literally dying in protests. It was a BIG DEAL. Which is why tons of movies and tv shows have dealt with those issues in the ensuing 50 years.
If your movie says "the Vietnam War sucked" or even "Lots of American soldiers came back from Vietnam with incredibly severe mental and physical problems" -- that's not anti-military. That's the truth.
If you want rah-rah, "go Army!" then there are plenty of archived Army recruitment and propaganda films from the 40s, 50s, and 60s on YouTube.
