If you’re one of those people whose first instinct in cases of youth violence is to blame the parents, “ The Quiet Son ,” the new Venice-competing title from directors Delphine and Muriel Coulin (“17 Girls”) has a valuable perspective, telling the believably downbeat story of a 22-year-old French guy who becomes embroiled in right-wing street politics, exclusively from the point of view of his loving but uncomprehending father. If, however, you’re already of the opinion that the issue is more complex than simple parental negligence, the solidly straightforward film has less to offer, as it states and restates the problem of rising, increasingly aggressive alt-right sympathies among young, working class populations, without providing any novel or particularly useful insights into it.

Adapted by the Coulin sisters from the book “Ce qu’il faut de nuit” by Laurent Petitmangin, the film's main attraction, beyond its ripped-from-the-headlines topicality, is Vincent Lindon (so often cast as a blue-collar worker he could confidently launch his own line of high-vis jackets and durable workwear), once again delivering a compelling performance as a gruffly sympathetic everyman. Playing railway repairman Pierre, a father who has raised two sons alone after the death of their mother when they were boys, Lindon presents a completely convincing portrayal of Pierre's deep anguish as he gradually loses one of them to an ideology that, as a Frenchman of an age to have grown up in the wake of May ’68, he cannot fully comprehend.

The sons create a believable, though slightly formulaic, contrast between the bookish, Sorbonne-bound Louis (Stephan Crepon) and the sporty, technical-college dropout Fus (Benjamin Voisin), a nickname shortened from “Fussball” which he earned as a soccer-obsessed kid. That it has a German origin is unsurprising; the family resides in the historically disputed French region of Lorraine, which has its own strong regional identity, making its inhabitants easy targets for anti-immigration rhetoric on two different levels. “You can become French,” says Fus during a heated exchange with his dad, “But you are born Lorrainian.”

As the movie commences, Fus has already become involved with a group of far-right sympathizers, whom Pierre avoids and forbids Fus from associating with, as long as he's living at home. However, Pierre is unaware of the depth of his son's involvement - and how often he has lied about his whereabouts - until an SNCF co-worker claims to have recognized Fus among the group of agitators aggressively disrupting a left-wing leafleting campaign. Pierre instinctively covers for his son but confronts him at home, leading to the first of Fus' many departures. Yet, he always seems to gravitate back home, where he will always be forgiven. One of the movie's strengths is the touching closeness that exists between all three characters, even when any one of them is at odds with the others. One night when Pierre stumbles in late after drinking away his worries about his son, Fus sneaks into his father's room to gently remove the boots he never took off before passing out. The same applies to the brotherly bond, beautifully portrayed by Crepon and Voisin, with Louis occasionally siding with Fus against Pierre, even though he doesn't share his sibling's burgeoning neo-fascist leanings, but just as often pleading with Fus to be understanding towards their father.

The Coulins, perhaps, overemphasize the everyday, ordinary nature of this good man's gradual heartbreak, and the filmmaking style reflects this. Apart from a few unusually expressive flourishes, Frédéric Noirhomme's cinematography is straightforward and unromantic, composed in a way that makes you oblivious to its composition. While there's no real need for this story to stretch to nearly two hours in length, the editing, by Béatrice Herminie and Pierre Deschamps, maintains a measured pace that neither drags nor creates artificial momentum. But at times, this restrained naturalism borders on blandness, as in a late courtroom scene where the speech Pierre delivers - though appropriate for his plain-spoken character - could have used a few more dramatic flourishes to achieve the emotional climax it never quite reaches.

“If you’re not with us, you’re against us,” Fus asserts, definitively, at one point. “But ‘us’ used to mean just us three,” Pierre replies, and Lindon’s cracking voice and weary visage could represent any parent who finds their children have grown into adults they no longer recognize. “The Quiet Son” doesn't break any new ground, and its filmmaking lacks inspiration, but a sensitive cast and a sobering story prove the truth that loving someone means letting them go. Even if that means they fall.