At the beginning of "Jarhead," young recruit Anthony Swofford (Jake Gyllenhaal) is given the business by D.I. Fitch. That's not "David Ian Fitch"; that's "Drill Instructor Fitch" (Scott MacDonald). If you've ever seen a movie about the Marine Corps or if you are the son of, the colleague of, the father of, the friend of, or were yourself a United States Marine, you will not be stunned by what happens next.

What you see is the full weight of the man and the institution against the fragile soul of the boy, but that weight is applied with such elan, such a flair for language, such a feel for the higher poetics of blasphemy and scatology and such a keen eye for weaknesses in the psyches of young men wishing they'd never left home, it's something akin to a religious experience in the Church of the Reborn Man. The Marines, like most military outfits, most sports teams, but precious little else in modern America, tear you down to build you up again, only different, better, smarter, braver. Maybe they make you a man, maybe they make you a machine, but they sure make you something you never were before. That process, always dramatic, has illuminated a number of movies.

For the record, the drill instructor, a noncommissioned officer, is that gentleman who handles the not-so-gentle transition from civilian to Marine in the ordeal known as boot camp, often at Parris Island, S.C. The process is not kind. It involves being addressed as an insect or other kind of low biological stratum, being forced to do calisthenics, tactical training, close-order drill, all at breakneck pace by a fellow of impeccable certitude who never uses his quiet voice. He gets you up early, he puts you to bed late; for some reason he himself never sleeps, gets tired, loses control, or wavers in his faith in the institutional wisdom of the entity he represents. Do you understand that, maggot?

For the record, we exclude sergeants who aren't drill instructors. (That would be Louis Gossett Jr., in "An Officer and a Gentleman," who was presumably an ex-drill instructor but whom the movie pictured, somewhat inaccurately, guiding a group of naval aviation candidates. Nor is tough Sarge Tom Berenger in "Platoon" a drill instructor.)

Of course the most famous drill instructor in history is Sgt. John Stryker in "Sands of Iwo Jima." If ever there was a part for which John Wayne was born, this is the one. I wish the 1949 movie were great; it's not. It's actually kind of an el cheapo Republic Pictures production, splicing in phony drama with actual combat footage in the best Poverty Row tradition. The dramatic arc is predictable: Stryker trains the men by humiliating and crushing them, then allows them to reassemble in his image. They hate him so much, you think: Just get a room, for God's sake.

But when they go off to war, his ministrations prove vital. Finally, when he sits back and says proudly, "I've never been so happy in my life," you know that's a bad career decision for the sarge.

Actually, a far less melodramatic yet equally mesmerizing film was released in 1957, directed and produced by Jack Webb, starring Jack Webb's favorite actor, Jack Webb. It was called "The D.I." If you saw this movie as a kid (guilty, guilty, guilty), you never forgot it: Webb's T/Sgt. Jim Moore represented a kind of magical quality. Webb, working from a script by James Lee Barrett and a deep love of the Marine Corps (though he'd been in the Air Corps in the war), really got the cadences of military life, the beat-beat-beat of the metronome as it ticked on, turning most into Marines, discarding others. Unlike "Iwo," it was a peacetime movie, concentrating on training issues, watching poor Moore try to get through to a goof-up named Pvt. Owens (the late Don Dubbins). Some of it seemed to have been written by Jean-Paul Sartre. When Owens slaps his face during a mock ambush to kill an insect, D.I. Moore orders the whole platoon to search for the corpse of the creature to give it a proper burial. One smart guy kills his own sand flea and races to the Sarge for release. The exchange goes something like this:

"Private Owens! Was that sand flea you killed a male or female?"

"Uh, I don't, uh, I'm not -- "

"OWEN! WAS IT A MALE OR A FEMALE?"

"I think it was male, sir."

"Then this ain't it. Keep digging."

But no real D.I. played the part until former Marine R. Lee Ermey did in Stanley Kubrick's great "Full Metal Jacket" in 1987. Where Wayne and Webb had just intimated the sheer power and bravado of such noble brutes, Ermey was the real thing, and, baby, did he make you feel it. He'd been hired by Kubrick as a technical adviser as they looked for an actor to play the role, but he was so damned good -- the guy really printed on the screen, much more vividly than any of the pretty-boy actors playing trainees in the recruit platoon -- that he got the role and carried the first half of the movie. It's a tribute to Kubrick's instincts that after this auspicious start, Ermey decided to act full time. He's still at it; why, just recently, he became a spokesman for Glock pistols!

In "Sands of Iwo Jima," John Wayne set the movie D.I. standard, a template Scott MacDonald follows in "Jarhead."