I am lately persuaded that the fifth horseman of the apocalypse drives a small Japanese pickup truck.

They are the nightmare image of the cable-news age, these battered vehicles, packed with men and small boys armed to the teeth and willing to kill anyone who crosses their path. They destroy not only lives but society itself in the ruined countries where they hunt.

This image has not been lost on Hollywood, always on the lookout for the latest deadly maze to run their action heroes through. Several films have exploited the grim chaos of civil war in Africa but one of the best may be director Edward Zwick's "Blood Diamond".

Solomon Bo (Djimon Hounsou) is a subsistence fisherman in Liberia. He has a rare possession in this war-torn country, hope that his son, Dia (Kagiso Kuypers), will do well in school and become a doctor, until one day he hears the sound of approaching trucks.

"Blood Diamond" scatters Solomon's family into the iconic horrors of African violence; his son is conscripted as a child-soldier for a rebel army, while the rest of his family disappears into a tide of refugees.

Solomon escapes slave labor in a diamond mine and forms a wary alliance with Danny Archer (Leonardo DiCaprio), a mercenary and smuggler. Danny wants a large diamond that Solomon hid during his captivity and Solomon wants his family back.

What works in "Blood Diamond" are its relationships. It doesn't have the inventive script of, say "The Constant Gardener" - in fact it reworks many of the formulas of action films - but Zwick, who learned his trade in relationship-heavy TV dramas ("My So Called Life", "Thirtysomething," and "Once and Again"), knows a thing or two about building emotional rhythms and transforms clich