Every week this summer, we'll be taking an historical tour of the Hollywood blockbuster by examining an older film that is in some way a spiritual precursor to one of the weekend's wide releases. This week: while it's probably the case that no movie has ever matched The Expendables in assembling such a uniformly all-star cast of action icons, it's hardly invents the first ensemble action film - and some of its predecessors have fairly well-stocked casts of famous people, at that.

I do not know if 1967's The Dirty Dozen represents the very first time that a movie treated upon the idea of a band of down-and-out criminals and lowlifes being assembled in time of war to do That One Hopeless Mission That Nobody Else Would Dare; though I rather doubt it. It's not even worth debating, however, that The Dirty Dozen - the fifth-highest grossing film of its year - is the reason why there have been so goddamn many of the things ever since. Take one marquee star for the main character, add a bunch of famous people and hot up-and-comers around the edges, and give 'em impossible odds and plenty of Nazis to fight: cinema gold, right there.

Forgive my snark; for however trite the scenario of The Dirty Dozen looks now, it's still better than all but the best of its copycats; good enough that its legacy still reverberates all this long time on (it is, for starters, the most obvious, overriding influence on Quentin Tarantino's Inglourious Basterds - a great deal more influential, in fact, than the film's namesake, The Inglorious Bastards of 1978. Which also owes a pronounced debt to The Dirty Dozen). It is, truthfully, a pretty fine war action picture, suffering predominately from one of the most weirdly atonal screenplays of its era - or perhaps it's the just the directing that's atonal. Whatever the case, it results in a film that spends an extremely long time trying to decide what sort of attitude it wants to project, and ends up failing to cohere as well as it might - a damaging misstep for a movie of two-and-a-half hours, but not a fatal one.

The film begins on a note of sheer nastiness: the hanging of a pathetic, groveling man convicted by three separate courts-martial, begging for his life. The officer witnessing the execution is Major John Reisman (Lee Marvin), who seems stubbornly disaffected by the whole thing, but we shortly learn that this is at least partially a ruse; his presence at the hanging was in some way a punishment from his nemesis and former commander, Colonel Breed (Robert Ryan), a regulation-humping jackass who has made a hobby out of finding new ways to make Reisman - a bit of a hot-tempered freethinker, we're led to understand - suffer in silence. The only force standing between these men is the capable but not too capable General Worden (Ernest Borgnine), and it's he who gives Reisman the latest in an apparent line of "oh yeah, well deal with this!" assignments: in the run-up to D-Day, Reisman is to lead a team of twelve soldiers to an isolated château in France, where a number of important German officers will be resting. There, they are to destroy the château, wiping out a major portion of the Nazi hierarchy just in time to leave the Germans helpless in the face of invasion.

Suicidal enough, and Reisman knows it. The rub is that his twelve men are to be culled from the ranks of military prisoners, American soldiers convicted of murder or various other terrible crimes. Meaning that before he can lead a squad to its almost certain doom, Reisman must form that squad from a dozen violent sociopaths.

The dozen men (who are called "dirty" after they mount an anti-bathing protest, in a line of dialogue that is just way too precious and on-the-nose for my tastes) are a satisfyingly programmatic blend of types: the stoic one who's clearly a moral sort caught in a bad situation, Joseph Wladislaw (Charles Bronson, one of the bigger "name" actors out of the batch); the loudmouth with a chip on his shoulder, Victor Franko (John Cassavetes, Oscar-nominated for a role he took largely for the money to pay for his directorial effort Faces); the good-natured Chicano, Pedro Jimenez (Trini López, popular music star); the angry black man, Robert Jefferson (NFL superstar Jim Brown, in the role that drove him from football); genial idiot, Vernon Pinkley (Donald Sutherland, in his star-making performance); and most promisingly for the sake of future drama, grinning psychopath A.J. Maggott (Telly Savalas), a man who believes that God wants him to murder sexually promiscuous women.

The Dirty Dozen cleaves rather unmistakably into three parts: in the first, Reisman meets his team of misfits and quickly understands that, in order to make proper soldiers of them, he's going to have to break their dark little souls; in the second, the team, having gelled into a whole under Reisman's torments, learns how to work together and be an unstoppable machine; in the third, they conduct their assault of the château. Their bloody, bloody assault of the château. And this is where that weird atonality kicks in. For the emotional structure of the film also cleaves into three parts, beginning with the fairly grim and mean-spirited opening - that ruthless hanging scene provides the template for what follows, whether it's the look of pure malice in some of the prisoners' eyes, or Reisman's entirely languid approach to psychologically torturing his charges. The third part abandons conceptual grimness for flat-out cruelty: by the standards of 1967 (a year in which Bonnie and Clyde was shunned in some corners as outright violence porn), it is unthinkably grotesque, and it still has quite a sickening kick to it all this time later. Director Robert Aldrich, whose career beyond this film hasn't really survived in the public consciousness (though What Ever Happened to Baby Jane? has its cult), was one of those man's man directors, who wasn't afraid to stare, unblinking, at the carnage his characters' masculinity wrought, and his presentation of the third act violence is absolutely pitiless, a bitter reminder that there's no morality on the battlefield, and awful things happen on both sides. The mores of the time ensure that there's no hyper-violence on the lines of Saving Private Ryan, God knows, but you don't need buckets of gore to get the point across, not when you can make every character death seem both shockingly sudden and agonisingly drawn-out at the same time. Aldrich even beat Tarantino by 42 years in depicting a mass-killing scene in which Nazis are offed in a way that bears certain unmistakable visual echoes of the Holocaust; and extra points to Aldrich for being entirely aware of the moral gravity of what he was doing.

Ah, yes - but what of the middle part, by far the longest? Taken in and of itself, it's perfectly fine stuff, but sandwich inbetween the dark first act and the unrelenting third act, I don't know what the hell to make of it. Basically, the bits in which the Dirty Dozen start to really work together as a smooth team prefigures not the "war is hell" bombast suggest by its blood-soaked climax, but the "war is hella funny" territory of M*A*S*H and Kelly's Heroes (both of which also co-starred Donald Sutherland, in what is presumably a coincidence). The mood of this central sequence is very much a mood of boys hangin' out, being boys, rehearsing their great impending mission using the jolly bravado of a heist film when they're not busy taking the piss out of Colonel Breed. There's an extremely long sideplot in which Reisman proves the efficacy of his men by having them kidnap Breed during a war game, for example - a lovely bit of character work, no doubt, but an awfully long stretch for a movie that could probably do with some trimming.

It's important to note that E.M. Nathanson's novel didn't extend much beyond the second act; the bulk of the attack, and its attendant brutality, was invented by screenwriter Nunally Johnson and Lukas Heller. So there is, at the very least, an explanation for why the film shifts so damn hard from breezy lark about ragtag miscreants in war to hideous, soul-shattering depiction of men dying like animals. The explanation doesn't make the shift any easy to weather, mind you.

I wonder if that shift really needs to be weathered, at that. Set aside the ending for a quick moment, what we have is an altogether nifty piece of Hollywood war entertainment, moving from squickiness to cockeyed fun in short order, carried at once by Aldrich's brusquely efficient directorial style, and a phenomenally well-chosen cast. Supposedly, John Wayne was the original choice for Reisman, skipping out when he had the chance to cheerlead for Vietnam in The Green Berets; and though I am certainly a Wayne fan, I absolutely can't think of him in this role, not when Lee Marvin comes and blows it away like he does. Does Reisman require the heaving weariness and impatience that Marvin brings to the character, or does it only seem that way since Marvin's embodiment of those values is so effortlessly iconic? I cannot say. And while no other actor has to do as much work as Marvin, I can think of at least two other performers whose very physical appearance, to say nothing of their acting, nails down the essence of the character in an instant: Borgnine's puffy, overwhelmed Worden, and Bronson's reflective Wladislaw.

The first two hours (or rather, just a bit under that) are such a pleasant example of the Hollywood machine cranking out a serious but undemanding war picture (albeit one that's too long by at least one stretched-out subplot) - did the writers and Aldrich intentionally trigger that massive shift into brutality as a means of putting the lie to the typical gung-ho war movie? Vietnam was still young in '67, and the idea of a movie about World War II that was so much happier glaring at the violence of combat than it was praising the fighting spirit of the U.S.A. was hardly intuitive (and to a degree, it still is: if you want to make a scathing anti-war film, WWII isn't the one you're likely to pick). I wonder if the seeming biggest weakness of The Dirty Dozen is an artifact of a time when massively violent war movies weren't de rigueur, when it's abrupt third-act shift back to the darkness of the first act wasn't a miscalculation so much as a conscious and deliberate sucker punch. If that's the case, it leaves an already marvelous war film significantly more crafty and potent than I'd have given it credit for.