It’s a testament to the enduring power of cinema that even a bad movie can have something in it that gets to you. And most of the time, that something is a performance, a presence or even just a face.

“Warhorse One” is a slow, sentimental slaughterhouse of a thiller, an “extraction” combat film about fetching Americans from Afghanistan as the country fell. It’s overlong and over-edited, laboring over the most inconsequential sequences, never letting a single shot of a commando checking his gear suffice when a dozen cuts will drag that out.

It plays politics with the war, having some Pentagon war hawk bitch about “this administration” pulling out without mentioning that was scheduled by the “last adminstration,” the one that “negotiated” the release of 5,000 of the guys who took over the minute the U.S. was out the door.

But as our title character, “Warhorse One” — played by co-writer/co-director Johnny Strong, a bit player/supporting player in TV and film since the ‘mid-90s — plucks the lone survivor of a massacred family of American missionaries up, we’re faced with the same thing his codenamed character is.

It’s a little girl in mortal peril. Look at that helpless, shocked face. You’ve got to do whatever it takes to save her.

Athena Durner plays Zoe, a child of five who becomes “the objective” in this lumbering, first-person-shooter thriller about a sole surviving “frogman” trying to get this one child chased by scores of glowering, murderous Taliban to a constantly-delayed exfil point.

Neither player has much of a role. The characters aren’t well written and the material doesn’t demand much in the way of performances. But Little Miss Durner gets a lot of pathos and protective empathy out of just a look. Yes, sometimes casting IS everything.

Warhorse One falls out of the plummeting chopper when it’s shot down. But a couple of minutes to collect himself, and maybe 37 edits to show him gearing-up and switching on his coms and “I am on my feet and I am good to go.“

The mission? Track down the missionary family fleeing in their Izuzu Trooper. Sure, but only AFTER he’s disobeyed orders and shot a bunch of the Taliban who shot down his chopper.

Only Zoe survived among the missionaries. Most of the trauma of what she saw — her family murdered in front of her while she cowered — will probably show up as PTSD. She’s more timid than shocked and broken-hearted. She’s leery of the SEAL with the silencer on his rifle.

“Papa says guns never solve problems.”

“Yeah? That’s why I always carry a knife.”

Over the course of a day or two, they are hunted, shot at, snatched and grabbed as they struggle through the wilderness on their way to safety.

She’ll have time to let him see her teddy bear. He’ll have a moment or two to teach her how to throw a knife.

The locations look more like Butch and Sundance’s Sierra Nevada stomping grounds than Afghanistan. The Afghan combat film tropes — “eye in the sky” command center direction, the suicidal fanaticism of their foes, that silenced machine gun fired by the omnipotent SEAL who never runs out of ammo — will be almost too familiar to anybody who’s ever seen one of these films.

And passing through that terrain and checking off those combat-genre-boxes seems to take forever, only partly because of the material’s over-familiarity and the whispered dialogue (more accurate than movies that shows hunted American soldiers shouting).

Any time the editing calls this much attention to itself, you know they’re trying to massage some energy and ugrency into a slow slog of a narrative. It rarely works.

But that kid makes things better, just by giving the jaded warrior hauling her out a mission, just by the implied pathos of her presence. Strong doesn’t really “play” this, but we infer it, no matter how one-dimensional his character and performance are. If he was as good as her, then simple genre pic or not, we might have had something here.

As long as Strong’s been in the business, playing soldiers (“Blackhawk Down,” most famously), you’d think he’d have learned that old W.C. Fields maxim, the one about never working “with children or animals.” Because whatever else they demand on the set, they’re sure to upstage you every time.

Rating: R, graphic violence, some profanity

Cast: Johnny Strong, Athena Durner and Raj Kala

Credits: Scripted and directed by Johnny Strong and William Kaufman. A Well Go USA release.

Running time: 2:05