Maybe because the opponent is so terrifying and insidious ("an allergy of the body, an obsession of the mind," someone calls it here), our desperation to win the war against drugs detailed in "Traffic" has made it the most unexamined conflict of our time, something we are more than willing to throw dollars at but not so eager to actually analyze and reconsider.

Given that, it took a certain amount of nerve to tackle the chaotic, unfocused, largely unsuccessful waste of lives and money that is the drug war today in a major motion picture with an ensemble cast including Michael Douglas and Catherine Zeta-Jones. Complex and ambitious, "Traffic" is that film, and its examination of how pervasive drugs are, how wide a swath they cut in our society, though not always completely successful, is yet another indication of how accomplished a filmmaker Steven Soderbergh has become.

Soderbergh, whose equally sure-handed but very different "Erin Brockovich" came out earlier this year, has once again opted for a change of pace. For one thing, as written by Stephen Gaghan (based on a British TV miniseries), "Traffic" effortlessly intertwines several complex stories across two countries and several cities without ever dropping a stitch.

At the same time, using the pseudonym Peter Andrews, Soderbergh has expertly shot the film himself in a neo-documentary, run-and-gun style whose emphasis on held-held camera work adds to its immediacy (Soderbergh has mentioned Costa-Gavras' "Z" as his model here).

Gaghan ("Rules of Engagement") has clearly done considerable research into the film's theme, and his script is strongest in its broad outlines, its ability to convey lots of information about the drug trade and show it to be a kind of pernicious octopus, with tentacles powerful enough to make almost everyone it touches corrupt, complicit or potentially so.

Unfortunately, "Traffic" is much less secure when it comes to dialogue and the creation of individualized characters. Some of its narrative threads are noticeably less compelling than others, and its people, no matter what social strata they occupy, have a tendency to sound a lot like standard brands.

While keeping the notion of intertwined stories from the British original, "Traffic" has sensibly changed the geographic focus from the Turkey-Britain drug trade to the more near-at-hand Mexico-U.S. situation. And by adroit use of filters and other techniques, Soderbergh has given each segment distinctive visual markings: a brown cast for Mexico, blue for Cincinnati and environs, a bright look for San Diego.

The Mexican section (in Spanish with subtitles) is by far the most effective, partially because it's got the film's best performance. That's by Benicio Del Toro, an actor ("The Usual Suspects," "Snatch") who's always been much admired for his subtle power but whose nuanced authority has never been more on view than as a state policeman who goes to work for Gen. Salazar (an effective Tomas Milian), the army's designated illicit drug fighter.

The film's biggest star is Douglas, a solid choice for Robert Wakefield, an Ohio Supreme Court judge who's just been selected as head of the Office of National Drug Control Policy. A square shooter who believes in his mission, Wakefield just happens to have a 16-year-old daughter (Erika Christensen) who, unknown to him, is a major narcotics abuser. When the judge says, "It's time to see the front lines," he doesn't realize the battlefield is his own bathroom.

Weakest of all in terms of plausibility is the section involving Zeta-Jones as Helena Ayala, a pampered wife who suddenly discovers that her husband (Steven Bauer) and his oily attorney (Dennis Quaid) are major drug players. Even with the expert assistance of Don Cheadle and Luis Guzmán playing DEA agents, this plot strand takes turns that are way too questionable for its own good.

No matter what straits these people find themselves in at the film's opening, "Traffic" inexorably tightens the noose around them. If the film's plotting has a flaw, it's that, in its eagerness to make its points in an emotional way, it falls back too readily on the excesses of melodrama. Sometimes we feel we're watching an updated version of "Marijuana: The Weed With Roots in Hell," or, to go back even further, a dramatization of the titillating horrors faced by young women in the dread clutches of the white slave trade.

Finally, and perhaps inevitably, one of the difficulties with "Traffic" is that it feels like the filmmakers are tiptoeing around the implications of their good work. As a big-budget film in a controversial area, "Traffic" seems especially eager to be seen balanced, to be fair--for instance, to the hard-working and sincere anti-drug agents putting their lives at risk. So though it takes important steps in that direction, the film pulls back from what seems to be its own logical conclusion: No matter how much money we throw at the drug problem ($45 billion per annum at last count) and how heroically they're implemented by those at the front lines, current policies simply do not work.

No one expects a Michael Douglas-starring film, and one that has Sens. Orrin Hatch, Barbara Boxer and Charles Grassley playing themselves, to take the kind of strong stance for drug decriminalization that, for instance, New Mexico's Republican Gov. Gary Johnson has. Still, many of the film's stronger moments, like Douglas' character getting absolutely no response when he asks for aides to think out of the box about the problem, point in that direction.

Given what this film shows, a clearer stand on decriminalization or even treatment in place of prison seems in order. Without one, watching "Traffic," artfully made though it is, feels a little like seeing a version of "The Insider" that thought it politic to waffle on whether cigarettes were a danger to your health.

MPAA rating: R, for pervasive drug content, strong language, violence and some sexuality. Times guidelines: scenes of torture and an overall air of pervasive violence and menace.