Directed by Stephen Gaghan, starring George Clooney, Matt Damon, Amanda Peet, Jeffrey Wright, Chris Cooper, William Hurt, Tim Blake Nelson, Christopher Plummer, Alexander Siddig and Mazhar Munir.

Geopolitical thriller 'Syriana' is a wide-ranging look at the global oil industry from writer/director Stephen Gaghan. Gaghan won a Best Screenplay Oscar in 2000 for 'Traffic', a similarly broad examination of America's war on drugs. 'Syriana', however, is a more complex - and more rough-edged - film which raises more questions than it answers. Ambitious and demanding, 'Syriana' is peopled with CIA operatives, American executives, Arab princes, religious zealots, terrorists and economic opportunists, all of whom are connected, in one way or another, to the oil industry.

George Clooney, who also executive produced, features as veteran CIA agent Bob Barnes. Bearded and bloated (he gained 35 pounds for the role), Barnes is a long-term field operative for the CIA's war on Middle Eastern terrorism who has never been afraid to get his hands dirty. But the rules are changing - seasoned agents are no longer important when reconnaissance can be done by satellite and assassinations by pushing missile buttons. He is struggling to find his own place in this new world, and trying to put his son through college, but Barnes is only one small element in 'Syriana's big dirty picture.

The narrative kicks off with a fictional, oil-rich, emirate in the Persian Gulf announcing that it has transferred drilling rights from giant Texas firm Connex to a higher Chinese bid. Connex, which now needs new territory to maintain its production capacity, decides to merge with a smaller firm called Killen, owned by Jimmy Pope (Cooper), which has acquired the drilling rights to a field in Kazakhstan. Smooth Washington lawyer Bennett Holiday (Wright) is given the responsibility by his power-broker boss, Dean Whiting (an icily patriarchal Plummer), of ensuring that the US Department of Justice approves the merger - whatever it takes.

There's also energy analyst Bryan Woodman (Damon), willing to use the accidental death of his son at a party thrown by Prince Nasir (Siddig) to further his own ambitions. The wild card of the pack, Wasim Kahn (Munir), is an impoverished Pakistani oil field worker employed by Connex who loses his job when the firm loses the drilling rights to the Chinese, and becomes easy prey for a charismatic extremist.

The maze of complicated storylines, only hinted at in that summary, gradually weave together to create a picture that illustrates the very human consequences of the ruthless drive to control the world's oil supply. Despite a running time that is slightly over two hours, Gaghan does not manage to make all his intended connections but he hits hard and often enough to make this not matter. The brilliant ensemble cast - Tim Blake Nelson, playing a Texas oilman and a member of the shadowy Committee to Liberate Iran, gets a particularly impressive "Corruption is our protection!" speech in his small role - along with a script that finds faults with everyone, from the top of the oil industry pyramid to the everyday petrol consumer, is what makes 'Syriana' such thought-provoking filmmaking. This is a movie which demands, and rightly so, your attention.

Caroline Hennessy