The word of mouth on The Last Full Measure ought to be terrific, in part because the people most likely to see it will be inclined to go with its flow. It’s impossible to avoid the word “old-fashioned” here, because the movie is indeed a throwback to patriotic war films of the past, in which individual heroism in battle is detached from the politics of the conflict — in this case, the Vietnam War.

The Last Full Measure takes place largely in 1999, as a (fictional) Department of Defense staffer, Scott Huffman (Sebastian Stan), reluctantly takes on the effort to upgrade an Air Force enlisted man’s posthumous honor from the lesser Air Force Cross to the Medal of Honor, the military’s highest award. The case is real: William H. Pitsenbarger, called Pits, died in 1966 after dropping into an ambush to help evacuate wounded soldiers from the Army’s 1st Infantry Division. After attending to casualties, Pits (played in flashbacks by Jeremy Irvine of War Horse) elected to stay and fight and reportedly helped save the lives of dozens of men before being killed. He was 21 years old.

In 1999, Scott travels the country and even visits Vietnam in order to interview survivors of the battle, and the movie trots out a Who’s Who of top-notch character actors: William Hurt, Samuel L. Jackson, John Savage, Ed Harris, and the late Peter Fonda, in his last role. Each one delivers a Supporting Oscar-worthy performance, along with fine “present day” turns by Christopher Plummer and Diane Ladd (as Pits’s parents), Bradley Whitford, Amy Madigan, and others. Dale Dye, a Vietnam vet who has served as military adviser on countless features beginning with Platoon (1986), even gets a substantial onscreen role, holding his own among the stars. Indeed, the steady stream of set pieces giving this remarkable cast moments to shine is among the chief reasons to see the movie.

Not surprisingly, The Last Full Measure also includes gentle lecturing about the value of the men who fought the often-despised Vietnam War, but the arguments are all grounded in character and come across more as humane pleas than political arguments. Although the ambush at the heart of the story is recreated and retold from several perspectives, the violence is never glorified, the enemy is not demonized (nor humanized, to be honest), and the logistics of what actually happened remain as murky as they likely were on the ground at the time. This is less The Green Berets and more Ordinary People: The chief battle is the trauma these men have to grapple with, and the Medal of Honor fight is the catalyst for their emotional epiphanies.

The arc of Stan’s character has become something of a cliche at this point: the stiff, career-focused functionary given an unwanted assignment that you know will make him a better man. (See also: Dark Waters, The Report, etc.) So while Stan does well enough, his chief accomplishment is becoming a credible sounding board and interrogator to draw out the older witnesses he interviews. That means the film takes a while to build emotional heft, but by the last 30-40 minutes, it’s powerful stuff.

The Last Full Measure — the title comes from Abraham Lincoln’s characterization of the noble war dead — is essentially a supersized Hallmark movie, but I mean that in the best sense. Remember, before Hallmark, Hollywood produced exactly these kind of lift-up-the-little-guy tearjerkers, many of them now considered classics by great directors such as Frank Capra, John Ford, and Preston Sturges. The Last Full Measure, as effective as it is, won’t be long remembered, in part because its audience has largely migrated to home viewing (where this movie could have a long afterlife) and in part because it’s an easy target for cynics and anyone who’d like to refight the politics and morality of the Vietnam War.

But its point of view deserves a platform. However they wound up in the jungles of Southeast Asia, most of the young Americans on the ground were just doing their best to keep themselves and their buddies alive, some of them heroically. That’s a truth that shaped many American lives. If you can’t let go of the impulse to “Yes, but…” their experiences, then you may not be the right audience for The Last Full Measure.

Grade: B-plus. Rated R. Playing at the Regal Biltmore Grande.

(Photo: Travis Aaron Wade plays one of the soldiers in the platoon that Pits tries to help in The Last Full Measure. Courtesy of Roadside Attractions)