Even Chris Hemsworth, who makes a living as a cape-wearing, hammer-wielding demigod, concedes that the image of a modern military leader rolling into battle on horseback makes for a curious spectacle.

"That absolutely got my attention, the visual uniqueness of this warfare," says Hemsworth of the Afghanistan war drama 12 Strong (in theaters Jan. 19), which premieres its first trailer at usatoday.com. "Then I found out what was actually achieved in those conditions. It blew my mind, to say the least."

Based on Doug Stanton's 2009 best-selling historical account Horse Soldiers, the movie follows Hemsworth's Green Beret Capt. Mitch Nelson, who immediately leaves his home and his wife (Hemsworth's real wife, Elsa Pataky) for combat after the 9/11 attacks.

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Nelson and a handful of Special Forces soldiers (played by an ensemble including Michael Peña, Trevante Rhodes and Michael Shannon) secretly enter Afghanistan and convince Northern Alliance General Dostum (Navid Negahban) to join forces against their common adversary: the Taliban and their Al-Qaeda allies.

Outnumbered 40 to one, the combined forces defeat the Taliban to capture the strategic city of Mazar-i-Sharif.

"It’s a fascinating story. These guys went in with the strong possibility that they would not coming be back," says producer Jerry Bruckheimer. "They had to go through these mountain passes the only way they could do it, on horses."

Hemsworth has experience with movie horsemanship from Thor. But this was a different level.

"Riding in full military gear with packs, weapons and all sorts of equipment is a whole other thing," says Hemsworth. "But it was a hell of an exciting shoot for obvious reasons, including getting a horse to hit his mark on camera while you're giving a line. That's not easy."

Even the least horse-savvy actors (Hemsworth isn't naming names) got a pass since the actual soldiers had little or no saddle experience, receiving basic riding instruction before battle.

"So we didn’t need to look like the best horsemen, but rough, dirty and unpredictable," says Hemsworth. "And that’s how it felt most days."

The real Special Forces showed uncommon grit and the ability to work with allies on the ground for a common objective. Upon taking the city back, they were hailed as heroes.

"It’s one of the few tales out of our current history that shows how America can respond in a positive way, helping people," says Bruckheimer. "They went in there and got the job done, driving the Taliban out and changing the war."

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Though battle details were kept classified for years, the horse soldiers are finally getting their due. A bronze statue depicting a Green Beret soldier on horseback was unveiled in September 2016 at Ground Zero in New York. That's a worthy tribute, Hemsworth says.

"As soldiers, they put themselves in extraordinarily dangerous situations for the benefit of others," the actor says. "But these men embedded themselves and worked diplomacy with the locals to free the oppressed. It’s insanely impressive."