The two aims of Blood Diamond are to provide all the rollercoaster thrills of a rip-roaring action-adventure epic, and to present the viewer with a dossier of statistics about the human cost of the diamond industry. It does both of these things extremely well, the only flaw in the gem being that it doesn't always do them both at the same time.
It's set in 1999 in Sierra Leone. Djimon Hounsou is a fisherman who lives the simple life, a world away from the civil war, until a band of rebels raids his village (in a scene oddly similar to the one at the start of the recent Apocalypto). The rebels force him to pan for diamonds, and he unearths a 100-carat pink stone, which he manages to bury just as government troops charge in. Leonardo DiCaprio, playing the Humphrey Bogart role of a self-centred mercenary who might just end up doing the right thing, promises to help Hounsou track down his family if Hounsou will lead him to the pink diamond. DiCaprio in turn needs the help of an American journalist, Jennifer Connelly, who agrees to aid the men in return for inside information about how diamonds which cause and finance nationwide carnage can wind up in respectable jeweller's shops.
Hounsou's role in the film is to suffer nobly, and Connelly's job is to look as if she's in a fashion magazine, not a war zone. But DiCaprio deserves his Oscar nomination for the breathtaking intensity of his performance. Fully convincing in a grown-up role at last, he does so much running, shouting, sweating and smoking that he's lucky he doesn't have a coronary.
For a while, the film is as tough and energetic as his contribution to it. The plot hurtles along, and there are some shuddering scenes of violence, often perpetrated by brainwashed child soldiers. It's in the second half that the action and the facts go their separate ways.
Perhaps Zwick and the writer, Charles Leavitt, were loath to waste any of their research, because they keep halting proceedings while the characters deliver history lessons and what's-my-motivation autobiographies. Most of those lectures could have been cut, and considering that the film is nearly two-and-a-half hours long, it wouldn't have done the running time any harm if they had.