A relatively conventional can’t-we-all-get-along message is served up in an intense package in “American History X.” Already controversial due to the neo-Nazi leading characters and the final cut dispute between New Line and first-time feature director Tony Kaye, resulting film digs to uncommon depths in examining the roots of prejudice and the wages of hate-inspired violence. This jolting, superbly acted film will draw serious-minded upscale viewers interested in cutting-edge fare and the latest outstanding performance by Edward Norton.

At a time when most American films steer clear of difficult subjects and are afraid even of unhappy endings, “American History X” jumps right into the deep end and navigates through it with intelligence and, for the most part, psychological plausibility. While the storytelling lapses into the pretentious and the overheated at times, and certain character transformations are presented without enough dots being connected, pic’s power, integrity and truthfulness are sobering and impressive.

It is possible that some otherwise well-disposed critics may restrain their praise, even unwittingly, in knee-jerk sympathy with director Kaye, who disowns this cut and lost his bid to take his name off the picture. But while the film has its flaws, it is by no means messy, nor does it feel sanitized or airbrushed.

Startling black-and-white kickoff has teenager Danny Vinyard (Edward Furlong) bursting into the bedroom of his older brother Derek (Edward Norton) to tell him that two young black guys are breaking into his car out front. In a fury, Derek pulls out a pistol, charges out into the night and without hesitation guns down the two kids before being arrested.

In the follow-up color sequence, Danny, who has a shaved head to go with his recalcitrant attitude, is upbraided by his black high school principal, Sweeney (Avery Brooks), for having written a favorable book report on “Mein Kampf.” As a corrective, Sweeney insists that Danny take a private course with him he calls American History X and, for his first assignment, Danny is told to write a paper on his brother Derek, a former brilliant student of Sweeney’s who has just been released from prison after serving three years for the nocturnal shootings and, it appears, is the reason for Danny’s own burgeoning racism.

Danny’s account of his brother’s life up to the night of violence effectively sets the picture on dual tracks. The extensive flashbacks, all shot in monochrome, chart Derek’s rise as a charismatic leader of a bunch of previously aimless malcontents along the beach in Venice, Calif. Intercut present-day footage, in color, presents the matured Derek’s difficult process of trying to disengage from the neo-Nazis, for whom he now has godlike status, and to slowly convince his astonished brother of the error of their old, hate-filled ways.

Always a bright kid, Derek had his head turned around when his firefighter father was murdered by black criminals when he tried to put out a blaze at a crack house. Overcome with rage at blacks as a result, Derek found a channel for it with the insidious help of a shadowy white supremacist, Cameron (Stacy Keach), who fed the young man’s resentment with propaganda, and dropped him in among the shiftless skinheads, who quickly embraced Derek as a leader with a vision.

Derek, whose bedroom is draped with Nazi photos and paraphernalia, becomes the de facto head of the working class household, which, in addition to his idolatrous brother, consists of his ailing mother (Beverly D’Angelo), who spends most of her time in bed smoking, and two sisters. In a series of three scenes of ever-escalating shocking violence, Derek puts words into action by leading his goons on a raid of a Korean-owned grocery store; verbally and physically attacks his mother and older sister while kicking his mother’s Jewish would-be new boyfriend (Elliott Gould) out of the house, and, in a scene that will have many averting their eyes, is shown horrifically finishing off the black kid from the opening scene who had the misfortune of only having been wounded.

All of these grisly but gripping events are invested with credence and additional force by virtue of Derek’s persuasive intellect and authoritative way of delivering his message. Not unlike his hero Hitler, Derek gives lowlifes and hooligans a sense of purpose, and “legitimizes” gangsterism through a political cause. David McKenna’s screenplay can effectively trade in the issues it raises because it seeks their origins and causes, which it argues lie in the home.

Although it continues to mix past and present, pic’s second half tilts toward Derek’s post-prison sense of moral clarity and attempt to rescue his brother from the Nazi fold. But just as it’s revealed how Derek came to his senses thanks to some very nasty treatment by white power boys in the pen and his friendship with a black fellow inmate (a marvelous Guy Torry), Derek, upon his release, justifiably fears that both the skinheads and the blacks have it in for him. Final reels are steeped in paranoia and the threat of inescapable revenge.

However “compromised” his vision has become, Kaye’s scenes register with tremendous power as well as with a certain fierce beauty. For years a successful commercials and video director, Kaye, who also served as his own cinematographer, indisputably knows how to stage dramatic action to potent visceral effect, and only occasionally goes too far and overstates his case.

McKenna’s acute script graphs Derek’s two major ideological/emotional journeys, shortcutting only in attributing the boy’s xenophobia to one racist remark by his father, and in skirting the manner in which Derek came under Cameron’s influence. Smart, realistic dialogue is relievedly free of cant and omniscient moralizing.

Bulked up, tattooed, goateed and shaven-headed in the flashback episodes, Norton is fearsomely fine as the good kid-gone-bad-gone-good again. The range he continues to exhibit is phenomenal, as is the insight he manages to bring to exceedingly diverse characters. His Derek mesmerizes even as he repels, and the actor fully exposes the human being behind the tough poses and attitudinizing.

In his best adolescent performance, Furlong is terrific and ultimately touching as the high schooler who, in the absence of a father, looks up to his strong older brother. Among the many significant supporting players, Brooks, as the sophisticated principal, D’Angelo, as a poor widow unable to cope with her unruly large family, and Ethan Suplee, as a hulking bully, stand out.