“The Last Full Measure” — which details the fight to bestow the Medal of Honor to medic William H. Pitsenbarger — is a true-life Vietnam war film that offers valor, a band of brothers, some dogged and righteous steadfastness, honor and grace. It also has a lot of loving things to say about fathers.

Director and writer Todd Robinson has not just assembled some of the best older actors working today — Christopher Plummer, William Hurt, Ed Harris, Samuel L. Jackson, Amy Madigan, Diane Ladd and the late Peter Fonda — but also elicited some astonishing dramatic moments on film.

But though Robinson handles the first half with skill and care — weaving battle scenes with craggy portraits of the survivors today — the second half disappoints as he amps and warps the Stateside struggle to get Pitsenbarger the medal, even creating a fictional Pentagon official charged with investigating the merits of the case. The film is “inspired by a true story,” which means Robinson can mess around with truth.

That’s a shame. There’s enough natural drama in the story of Pitsenbarger, who on April 11, 1966, was aboard a helicopter trying to rescue wounded Army soldiers surrounded by Viet Cong troops. The 21-year-old Air Force medic chose to drop down and help winch soldiers up to the chopper.

In four hours of hell, Pitsenbarger successfully evacuated nine soldiers before the choppers had to flee under increasingly heavy fire. The next day, his lifeless body was found lying next to men he didn’t know, but gave his life trying to save.

Bureaucratic hurdles ensue, though. Robinson creates Pentagon lawyer Scott Huffman to sift through the 30-year evidence. “Justice delayed is justice denied,” he is told by the character played by Hurt, who turns in a moving performance.

But Huffman, played by Sebastian Stan, is reluctant to get involved — “I don’t have time for this,” he wails — and much of the film is his growing embrace of the veteran community. The effort comes to a head when he must decide on his own honor or his career. There’s a double-cross, Pentagon intrigue, secretly taped conversations and a big Hollywood-style confrontation. It’s all hooey.

Much better is the portrayal of Vietnam vets still working through issues of guilt, PTSD and alienation. Huffman visits each vet at their homes and they all tell vibrant stories. Jackson has a wonderful aria in which he calls himself “a refugee in my own country.” Fonda plays a veteran so damaged by the war he stays awake at night.

Plummer as Pitsenbarger’s ill father describes how he regrets never getting to see his son fall in love or have a child, because only then could he understand fully how much his father loved him. “Dying isn’t harder than losing a child,” he says.

That — along with the character sketches of veterans — are the best parts of the film, not the conspiracies or the endless pats on the backs at the end. Pitsenbarger and his family deserve our endless thanks. That is clear. Despite its flaws, this movie reminds us all of the sacrifices made by soldiers and to be mindful of how we treat them when they come home.