The Commandant is carefully tutoring his boy soldier, Agu. He teaches him discipline. He inflames the child’s rage at the government troops who summarily executed his father and gunned down his fleeing brother.

Final test? Draw blood.

“Agu,” the silky-sinister Idris Elba tells little Agu (Abraham Attah), “you are going to kill this man.” He caresses a machete, and passes it over. Hack away, boy.

“Like chopping wood.”

“Beasts of No Nation” is a justly-celebrated boys-eye-view of civil wars of Africa, where children are taught to hate and kill, and ruthlessly do what they’re told by warlords like Joseph Kony and Abubakar Shekau. Writer-director Cary Joji Fukunaga, working from a novel by Uzodinma Iweala, does for Africa’s failed state conflicts what he did for North America’s migrant crisis in “Sin Nombre” — he puts human faces on it.

In an unnamed country (it was filmed in Ghana), Agu narrates his tale. War has torn his country, so “We are having no more school.” He and his mates — most look to be 10 or so — goof around, have burping contests, try to palm off a gutted TV to the indulgent Nigerian peace keepers.

“3D — Imagination TV” they shout, acting out music videos and fight scenes for the amused soldiers.

But then the factional government (NRC) troops storm in, the peacekeepers are gone. And even though the unarmed “buffer zone” folks want to resist, they are helpless against men with guns. Shockingly, the soldiers massacre the menfolk who haven’t fled.

Agu escapes. Until he’s captured by by the NDF, a leading rebel group.

The Commandant is in charge, but he’s leading children — a colorfully attired (or nearly naked) crew of kids, Agu’s age to upper teens. Traumatized by war, many of them orphans, they are open to Commandant’s sermons. And he is wise to their impressionable usefulness.

“The boy has hands to strangle…and fingers to pull the trigger. The BOY is very dangerous.”

Agu will learn. And he will tell us his story as he does.

“God, I have killed a man. It is the worst sin!”

The firefights are visceral experiences, the African settings beautiful, the situations almost beyond The most chilling thing about Fukunaga‘s film is how little it surprises us, how muted the shocks are. We’ve heard all about child soldiers, the mass kidnappings, the bitter blood feud nature of the wars. Joseph Kony became Africa’s most wanted man. For a while.

With subject matter this familiar, brisker pacing was called for. “Beasts” has more back story than it needs, more movie after its dramatic climax than is necessary. “African Civil War Fatigue” isn’t just a problem for TV news.

The kid is terrific, but from the moment he shows up, the movie is Elba’s. His easy charisma fits neatly with Commandant’s manner. He is fearless, perhaps a little stoned. Bullets whiz by but he stands tall, sizing up the situation, directing the action. He willingly sacrifices chunks of his battalion for his objectives, and he hides his true motives with ease.

“Beasts on No Nation” makes a terrific vehicle for Elba and a grim reminder that even if we’re tired of hearing of it, the Third World is in turmoil. States failing, refugees sweeping across borders.

And the cynical leaders of many a revolution are turning a generation of children into warriors, or cannon fodder.

MPAA Rating: unrated, with graphic violence, sexual violence, profanity

Cast: Abraham Attah, Idris Elba, Francis Weddey
Credits: Written and directed by Cary Joji Fukunaga, based on the novel by  Uzodinma Iweala. A Participant Media/Netflix release.

Running time: 2:17