Normally, we should be afraid, very, of the Hollywood paradigm wherein a white movie star becomes the locus for sympathy in a topical film about calamities in the Third World. But Edward Zwick's robust, nerve-wracking voyage through West Africa is potent stuff, wary of implicit racism, craftily conceived as a post-Conradian narrative, and visually hellacious. Leonardo DiCaprio seems suspicious, but he's no goody two-shoes—his Danny Archer is an amoral smuggler, a white Rhodesian with fond memories of apartheid, and an ex-mercenary nearly as conscienceless as the bloodthirsty rebel militiamen that rampage through the tiny nation (circa 1999) massacring civilians by the thousands.

With shades of Syriana, the film recognizes that politics boil down to money, and the struggle—between the RUF, the Guinea-based military, white guns-for-hire Executive Outcomes (given an alias), the monstrous Euro-corporation in control of the world's diamond market (De Beers, but code-named Van Der Kaap), and lone wolves like Archer—revolves entirely around diamonds. One fat gem, in particular, found by a fisherman (Djimon Hounsou) after being enslaved by the rebels, provides the movie with a concise and pulpy agenda that rescues it from easy liberal platitudes. Of course, there are some, courtesy of Jennifer Connelly's hotsy journo, but the siege scenes are tonic enough.

The film can be gruesomely graphic, and sometimes bizarrely so, given Zwick's dopey love of war, which time and again has served to muddy his humanistic melodramas (Glory, Courage Under Fire, The Last Samurai). But it's a riveting push in the bush, passionate and grueling (so many butchered children; caveat emptor, parents), with DiCaprio finally legitimizing his stardom with a commanding portrait of a full-on, three-dimensional adult male, riddled with bad experience, rotten self-justification, and homicidal skill.