Edward Zwick is an old-fashioned filmmaker, and Blood Diamond is an old-fashioned instructional film that tells us the real cost behind every diamond ring. I may be more receptive to its message than most; every holiday season, the diamond industry finds new ways to offend me, and I already knew a little of what’s shown here. Yes, men are pressganged into mining for diamonds by tyrannical warlords looking to fund their bloody revolutions. Yes, De Beers and others (represented here by the fictional firm Van Der Kapp) buy up diamond surpluses and store them, specifically to create artificial scarcity and raise prices.

But I didn’t know about the million-strong refugee camps left in the wake of these periodic surges of violence. I didn’t know how De Beers got around buying conflict diamonds (they’re smuggled into neighboring nations and bought there). Nor have I seen so vividly rendered the squalor that the world’s richest people make their fortunes in. In all these and other ways, Blood Diamond is informative and (I hope) transformative to audience members who knew nothing about the source of their jewelry. “People would not wear a diamond on their finger if they knew it cost someone their hand,” says one character in a particularly naive lapse of judgement for someone surrounded by the kind of violence pretty rocks can generate. But here’s hoping he’s right anyway.

But Blood Diamond is, like all of Zwick’s films, very conventional. Therefore it follows that if the film is going to be instructive, each of the major characters will represent a larger sociological trend in the conflict. Leonardo DiCaprio is Danny Archer, a native white of Africa who, just like his ancestors, has no problem bottom-feeding with the worst his continent has to offer if he can make some money out of it. He runs guns, smuggles diamonds, whatever—just so long as there’s profit to be made from it. Then there’s Solomon Vandy (Djimon Hounsou), a simple Mende farmer so quietly noble that even the little white lies Archer uses to surive offend and confuse. Finally there is Maddy Bowen (Jennifer Connelly), a ballsy American journalist who wants to tell the real story. The three are thrown together in search of a large pink diamond and Vandy’s son, and their interactions are more mostly successful at telling us what’s going on in Africa without being preachy about it.

Archer and Bowen, as the two single white characters thrown together in tough times, must naturally have some chemistry; I think it’s a rule in Robert McKee’s Story or something. But Zwick and writer Charles Leavitt keep a subdued approach to some of the story’s more obvious elements, and for that I’m thankful.

Africa, specifically Sierra Leone, takes center stage. There’s the refugee camps, the caravans of children with AK-47’s, the random and overwhelming violence, the revolutionary rhetoric cynically employed to cover up simple murderous bullying. I’ve seen two movies in two days—first The Good German, and then this one—that spend a lot of time talking about their locale. The former built its atmosphere admirably, but Blood Diamond succeeds in creating the look and feel of a whole continent. And it is a terrifying vision.

There’s a certain hokiness to Zwick’s The Last Samurai and even in Glory. Heroes were heroes, cultural differences were bridged, romances hinted at. But this hokiness in no way lessened the emotional impact of either film; even as you were aware of the machinations, they moved you. That emotional impact is what is ultimately missing from Blood Diamond. It’s a powerful film, intelligent, interesting, well-acted and well-scripted. But the resonance isn’t there. Instead, what could have been a great film is merely good.