During the slaughter of Japanese troops at Burma’s Walawbum in March 1944, members of the 5307th Composite Unit (Provisional), better known as Merrill’s Marauders, hurled — alongside mortars, grenades, bullets, and shells — various epithets, including the allegation that Hideki Tojo ate excrement. According to a Marauder staff sergeant, the Japanese yelled back, “Eleanor eats powdered eggs!” Whether this rejoinder was intended as a critique of Mrs. Roosevelt, K-rations, or both, it portended a wit rarely encountered in descriptions of the Burma campaign, and nearly impossible to render on film.

Samuel Fuller’s war pictures are besotted with gallows humor, but even he would have been hard-pressed to use this story (had he heard it), suspending the audience’s suspension for a collective, “Huh?” Indeed, the “powdered eggs” remark may well have heralded a dying fall: 800 Japanese soldiers died at Walawbum, as opposed to eight Marauders. The Marauder casualties were of a different kind: A third of them succumbed to disease, psychological breakdown, starvation, exhaustion, or a ferocious sense of betrayal. Still, as the new Warner Bros. DVD release of “Merrill’s Marauders” (1962) reminds us, Fuller’s compromised yet uncompromising movie, is by no means deficient in “huh?” moments.

At least four such moments underscore Fuller’s emphasis on mental dislocation in war: A dying soldier who screams, “Did they get Lemchek?”

is Lemchek; a group of exhausted men suddenly realize they can’t tell what day it is or the difference between a.m. and p.m.; the keeper of a much-coddled mule — named Eleanor — volunteers to carry its load and dies under the weight, and Sergeant Kolowicz (played by leathery Claude Akins) wakes to a bowl of rice, extended to him by a very beautiful, very old Kachin woman, before doffing his hat and blubbering inconsolably.

Another Fullerian moment was apparently designed just for the unit’s survivors. How would anyone else know that the actor playing General Merrill’s attaché, credited as Vaughan Wilson, is actually Major (later Lieutenant Colonel) Samuel Vaughan Wilson, a Marauder who served as the movie’s technical adviser and narrated the trailer, which survives as the only extra feature on the new DVD? That knowledge gives his character’s valedictory lines a kick: “Do you know what I’m going to do after the war? I’m going to get married and have six kids. Then I’m going to line them up and tell them what Burma was like, and if they don’t cry, I’ll beat the hell out of them.”

“Merrill’s Marauders” was not a project sought by Fuller. He wanted instead to film his own World War II story, “The Big Red One.” Jack Warner held it out as a carrot, so Fuller was sent to the Philippines with the Warner stock company of young television Western actors, including Ty Hardin, Peter Brown, Will Hutchins, and one middling star, Jeff Chandler, whose prominent cheekbones had pigeonholed him as an Indian chief. Chandler’s striking performance should have upped his stature, but he died before the film was released, a victim of medical malpractice.

The cinematographer on the project, William Clothier, specialized in Westerns and war films, but was not an ideal choice for the Cinemascope photography; his vistas are a bit too enchanting. And hack composer Howard Jackson came up with nothing but martial clichés, though Warner supplemented them with its library of stock music by Max Steiner and Franz Waxman, who wrote the great score for Warner Bros.’s first pass at the story, “Objective, Burma!” (1945).

In the end, Warner took the film away from Fuller, insisting on the ludicrously upbeat ending of a thoroughly irrelevant marching band. But it made no difference: By its final scene, the film has decisively undermined every illusion of military glory. From the first shots, which follow a nicely cobbled historical setup using newsreel footage and animation, Fuller shows the Marauders up against something more frightening than combat. As Charlton Ogburn Jr. wrote in his 1959 account, “The Marauders,” on which the film is based, “The major enemy was not the Japanese themselves, but your own apprehensions.” Fuller’s dialogue begins with apprehensions: “Another bend in the road,” a soldier says. “Wonder what’s behind this one.”

It was not an easy story to tackle — not for Warner Bros. and not for the Army, which had been torn between honoring (reluctantly, after a congressional hearing) the extraordinary bravery and fortitude of the Marauders and quashing the resentment of its members. Colonel Charles Hunter, who assumed command after Brigadier General Frank Merrill suffered a heart attack, protested that the force of nearly 3,000 volunteers — initially formed with the code name Galahad — had been “expended to bolster the ego” of General Joe Stilwell, the American commander of the China-Burma-India theater.

That may explain why history takes little interest in Hunter, though he was responsible for much of the unit’s success. In Fuller’s adaptation, which is filled with his usual nicknames (Bullseye, Chowhound), Hunter becomes Lieutenant Stockton, or Stock (deftly played by Hardin). One of the film’s most intriguing qualities is the relationship between Merrill and Stock — father-son with an undercurrent of homoeroticism. Stock undergoes a sea change from obedience to obstinate fury.

Yet for all the painstaking historical touches — leeches, the tapped Japanese radio wire, the “balletic” (in Ogburn’s description) dances of death, concrete fuel tanks at the dynamic railhead battle — this is a movie beyond history. Despite the documentary opening and the abrupt all’s-well finish, “Merrill’s Marauders” has no beginning and no end. It’s about a trial of endurance with no reward, no carrot.

The Marauders excited the public during the war, not least through the luck of alliteration. The volunteers who made up Galahad, including several sociopaths and others who won release from prison to join up (Galahad prefigured “The Dirty Dozen” school of wartime adventure), were formed as the 5307th regiment. That designation was changed to 5307th Composite Unit (Provisional), as leadership of a mere regiment was considered unsuitable for a brigadier general. A Time reporter, James Shepley, came to the rescue, calling them Merrill’s Marauders — a name the press could understand.

In 1944, when Raoul Walsh began shooting “Objective, Burma!” the Marauders offered an obvious inspiration for a fictional film about American paratroopers on a mission to blow up a radar station, unaware that they had become an expendable diversion. Paratroopers? Not a single soldier dropped into Burma from the air. Allies consisting entirely of men with names like Nebraska and Gabby? Burma was a mostly British-Chinese operation. That film, banned in England by an angry Winston Churchill, wasn’t the first instance of Hollywood’s oddly possessive attitude toward Burma: In “Bombs Over Burma” (1942), a Chinese woman and a two-fisted American bus driver save the country from a British spy.

By war’s end, Americans, too, looked sheepishly at the Marauders, as the army tried to play down the length of their tour and the grueling casualties, especially mental ones. It also suppressed John Huston’s documentary “Let There Be Light,” about psychiatric illness in the armed forces. Fuller shows how the successful occupations of Walawbum turned out to be the first of three missions, the second and third added without warning or respite. Within five months, the Marauders fought five major conflicts and 32 skirmishes, walking 750 miles in relentless heat, through polluted swamps and rivers, along jungle trails, over razor-backed ridges, and on tight mountain trails from which their pack mules fell into the ravines below. They survived on minimal K-rations with no change of uniform.

Of the 3,000 Marauders, only 200 were present at the final objective, the airbase at Myitkyina, after which the unit was quickly disbanded. Subsequent honors, including the Distinguished Unit Citation, satisfied few. Fuller may have realized that he failed to film the harrowing second half of the story, the aftermath — he set his next film, “Shock Corridor,” in an insane asylum. Warner Bros. similarly failed to do justice to this DVD; most films that get commentaries and featurettes don’t need or deserve them. “Merrill’s Marauders” does. At least the print is sharp.

Mr. Giddins is the author of “Natural Selection: Gary Giddins on Comedy, Film, Music, and Books.”