Hard rocks

In a brief rest from AK-47-toting rebels, a war-hardened Danny Archer (Leonardo DiCaprio) tries to make sense of human nature from the bloody chaos around him. Are people naturally good or bad? Nah, he concludes: "They're just people."

Most of Blood Diamond (rated R for strong violence and language) has the same tenor-frequent near-misses at profundity, and consequent lapses into the Africa-as-hellhole genre. As pure entertainment, the film is both heart-rending and enjoyable. As an advocacy piece against conflict diamonds-the illicit diamond mining that funds war-it's middling.

The plot follows diamond smuggler Archer and fisherman Solomon Vandy (Djimon Hounsou) through 1999 Sierra Leone as they try to uncover a valuable pink diamond. At the time, conflict diamonds funded rebels there and war in Liberia and Guinea.

If the film falls short on the big messages, many of its details are authentic: Archer's background as South African mercenary, his slang, and (thankfully) his accent. The rebels' limb-hacking, drunken rampages and use of child soldiers are striking on-screen. So is Vandy's reverence for education as a way to advance, distinctive among poor Africans.

But Vandy's purity contrasted with Archer's cynicism carries a touch of Rousseau's noble savage. In keeping with Hollywood cosmology, the biggest villain is the big diamond corporation Van de Kaap, representing the real-life giant De Beers.

Here is where the film is best viewed as more historical than current. Conflict diamonds have always been only a fraction of legitimate diamond mining, whose center is in southern Africa. When public knowledge of conflict diamonds grew, these countries instituted the Kimberly Process, a way to certify legal diamonds and protect their trade. According to Global Witness, conflict diamonds accounted for 15 percent of the world's illegal diamond trade about a decade ago. Now they account for less than 1 percent. For that reason, Blood Diamond's advocacy-and musings on the human condition-may be too shallow.