Ever since the first reports of “Rescue Dawn” began spreading across the Internet — complete with the news that it would be directed by art-house icon Werner Herzog, star bankable “Batman” leading man Christian Bale, and get a splashy July 4 release — questions have been swirling among observers: Why Herzog, and why again?

Ten years ago, the iconoclastic Mr. Herzog, famous for his bold, dark tales and his mystifying, eccentric heroes, made a documentary titled “Little Dieter Needs to Fly.” In that film, Mr. Herzog recounted the astonishing strength and persistence of Dieter Dengler, a young man who was shot down during the Vietnam War, endured months of imprisonment ,and who then escaped from the compound, overpowered his captors, and made his improbable journey through the jungle to reunite with his American comrades. It was an astonishing tale not only of imprisoned bravery, but of heroic survival in the wild, a story steeped in the sort of man vs. nature vs. himself formula that has led Mr. Herzog to peer deep into the human soul for decades.

That’s why, when “Rescue Dawn” was announced, Mr. Herzog’s fans took note. It was odd enough that such a prolific filmmaker wanted to return to the same subject matter (he’s typically overloaded with ideas). But more than a few observers questioned what he could possibly bring to a fictional film that he couldn’t have brought to the documentary.

The answer to that question comes late in “Rescue Dawn,” in two classic Herzogian shots that play out almost back-to-back. Paired together, they form a fascinating and haunting paradox that fits perfectly into the Herzog canon, steeped in the mystery of where civilized man ends and his animalistic nature begins. The first of the two shots is of a man deranged, the second of a man civilized; the first captures a raw and violent impulse, the second an act of calculated finesse. Put them together and you get a revelation as powerful as the closing shot of “Aguirre, Wrath of God,” or the haunting post-mortem monologues recorded by Timothy Treadwell while he was still alive in “Grizzly Man.”

The story leading up to those two shots is military legend. Dieter (Mr. Bale) is shot down mid-mission and falls back on his training to initially give his enemies the slip. He is soon found, tied, and shipped out to a prison camp, where he is offered freedom in the form of a letter he must sign denouncing America. He refuses even to look at it, and is thereby mixed in with the other American hostages, including Duane (Steve Zahn), who has the worn and weary face of a man who’s endured captivity for quite some time. As the days crawl by, Dieter comes to learn the rhythms of the prison, first in the cycle of meals and the agonizing sleeping conditions (all the prisoners are shackled together on ), then in the moods and temperament of the prison guards. The more the prisoners talk, the more Dieter is able to convince Duane that a wait-and-see attitude is unlikely to succeed: They will not be bartered, Dieter says, and there will be no negotiations for their release.

So Dieter devises an intricate plan for escape. When the day comes, the prisoners execute a classic jailbreak, throwing off their chains and launching a surprise attack. But that victory means very little in the big picture, for the dangers of the jungle that await, and they will eventually divide the men and lead Dieter to a place where his instincts must take over.

Just before his rescue, he finds himself on the banks of a river, shivering and starving. As a snake slithers across a boulder, Dieter grabs it, smashes it against the rock, and sinks his teeth into the snake’s flesh. It is a moment so fast and so raw, so confident and animalistic, that we see in him the aura of a survivor, willing to do absolutely anything to endure. In the midday sun, wading through the river, one man has connected with the darkest place of the human soul and, much like the penultimate moment of “The Shawshank Redemption,” clawed through the worst kind of muck to get there.

This makes one of the very next sequences that much more fascinating. When Dieter is rescued from the jungle and greeted by his comrades back in the civilized world with a hero’s welcome, it seems odd at first that Mr. Herzog, a filmmaker long obsessed with nature and the jungle, follows Dieter back home. But we see here, amid his homecoming, something more bewildering than anything we saw in that hut or along that jungle river: a smiling serviceman, getting along with his old chums as if nothing has happened. If Dieter on the riverbank is a man on the brink, then this is a man about town, a smiling, showered, groomed stereotype of a gentleman soldier.

Much of the credit for this jarring contradiction must go to the fiery Mr. Bale, who shrewdly wraps us so tightly in Dieter’s anxious desperation and uncontrollable hunger, that to see him smiling and chipper seems unnatural. Mr. Bale also keeps a firm hold on Dieter’s violent side, playing him almost as if in a pressure cooker, waiting to explode. When we meet Dieter, we come to know him as a methodical thinker. It’s only later that we realize he has the brute force to back up his solid thinking.

As he works with this fractured personality, Mr. Herzog, employing a more restrained style here, still finds contradictions everywhere he turns the camera — from the way Dieter both mocks and then comes to rely on the pathetic survival video he is shown early on, to the way that nature can be at once beautiful and deadly. Through it all is that smile, the smile of a survivor that should be something to celebrate, which Mr. Herzog instead transforms into something uncomfortable, even ominous. Stories of survival are typically about an exhale of relief, but “Rescue Dawn” is about a soul-shattering, involuntary gasp. Maybe that’s what drew Mr. Herzog back to the tale: Sure, little Dieter’s smiling at the end of his journey, but we get the sense the smile is only skin deep.

ssnyder@nysun.com