From the very start director Edward Zwick sets out to attract the kind of liberal open-minded intelligent audience that enjoyed "The Constant Gardener". Blood Diamond contains similar elements of political injustice, global exploitation of poorer countries by rich corporations, and characters prepared to stand up for what they believe in. One hopes it will do similarly well.

Conflict diamonds or Blood diamonds are gems of great value smuggled out of African countries in the midst of war for which large sums of money are paid, money that is then spent on more guns to further perpetuate killing. They may worth a fraction in the international diamond trade, but this still caused enough wealth to be ploughed back into guns that organisations like Amnesty International or Global Witness gave them the name of blood diamonds.

To further illustrate how dangerous they are, in Ed Zwick's thriller, we're transported back to the bloody civil war in 90's Sierra Leone where an innocent Mende Fisherman Solomon Vandy (Djimon Hounsou) is separated from his family by local RUF rebel marauders with machetes and later finds out his son has been kidnapped by the rebels. He is forced to work as a slave searching the rivers and lakes for diamonds.

At the same time we are introduced to a cynical local diamond trader Danny Archer (Leonardo DiCaprio) who thinks only of his next buck and how he can make a living from selling gems for arms.

Their paths cross when both end up in jail. By then Vandy has found a huge stone but hidden it, and Archer gets to hear about it when a fellow prisoner tells all that Vandy has such a stone and demands to know its whereabouts.

Into the mix also comes an idealistic US press hack Maddy Bowen (Jennifer Connelly) who gets to know Archer in a couple of chats that show a difference of opinion at a beach bar when she is off duty.

The main thrust of this film concerns all three of them. If Archer is to get this precious stone, he must first help Vandy locate his son, since Vandy will then be more amenable towards telling Archer of its whereabouts. To get to where the stone is, Archer must gain the allegiance and assistance of journalist Maddy Bowen who can cut through red tape and provide crucial cross-country transport across a country fiercely fighting civil war. Finally, Maddy isn't going to help Archer unless she gets something out of it too.

Like Constant Gardener, Blood Diamond intelligently opens up a world many will not know about and sets out deliberately to attack a diamond trade that shouldn't be dealing in stones that have cost many lives. The screenplay by Charles Leavitt leads you to realise that all the main characters are using each other in different ways and the performances from all three main actors are powerful and thrilling to watch.

Edward 'The Last Samurai' Zwick stages some great action scenes most notable of which is the Rebel arrival into the Capital Freetown which is positively thrilling and vicious to watch at the same time. You feel very close to what it may have been like at the time and angry that the paucity of media coverage and inaction by developed nations who didn't step in at the time to quell the outrages.

DiCaprio almost comes of age here playing such an anti-hero. He's well supported by Jennifer Connelly's fiery journalist and at the heart of the film, aside from the excellent suspense-induced sequences in war-torn Sierra Leone, is Hounsou playing Solomon as a proud, embittered, determined father who will never give up hope of seeing his family again.

The film plays out quite beautifully. With its heart is in the right place, it has a healthy dose of real danger running through it, the cynical Archer is always likeable purely because he's an uncomfortable hero and the only real weakness comes towards the end when the filmmakers choose to sidestep the chance to go for a punchier and more well-thought ending and opt for a pat one instead. Then again, this is a Hollywood production.

That can be forgiven though because until then Zwick doesn't put a foot wrong and Blood Diamond is still a forceful, tense and very satisfying film that in character development, plot movement and education of the political crisis in Sierra Leone in the 90's, is both informative and powerful in approach.