It’s Big Oil’s world. We’re all just driving around in it. And air-conditioning, Tivo-watching, iPoding and Googling in it.

If you hadn’t figured that all out, here is “Syriana,” a searing, bleak and unflinching thriller that embraces the big picture even as it zeroes in on several small ones. Stephen Gaghan’s densely scripted, magnificently shot and ably acted take on American Middle East policy has everything in it but Israel.

Israel doesn’t count. Israel doesn’t have oil.

George Clooney stars as Bob Barnes, a CIA veteran of Beirut and Tehran who’s a bit concerned about some shoulder-launched missiles that his government has lost track of. He writes memos, and that rocks the boat.

There’s a big oil merger that might have involved some chicanery by the moguls who engineered it – Chris Cooper, Robert Foxworth and Tim Blake Nelson. Jeffrey Wright is an attorney commissioned by his power-broker boss (Christopher Plummer) to find the illegalities in the deal before the government does.

Matt Damon is an energy analyst anxious to broker a deal in which his company advises an oil kingdom about to be run by Prince Nasir (Alexander Siddig).

Matt Damon, left, George Clooney, Alexander Siddig and Bashar H. Atiyat star in writer-director Stephen Gaghan's political thriller Syriana.

And a Pakistani teenager (Mazhar Munir) is among many who have just been laid off from their Persian Gulf oil refinery jobs in a Chinese takeover of their firm. Poor, oppressed by foreigners and their own government, they are ripe for recruitment by the forces of extremism that America is ostensibly most concerned about.

The bit players are just sacrificial pawns in a sprawling chess board that big D.C. attorneys, Texas barons and their government lackeys are manipulating. Barnes will face his darkest hour, Damon’s analyst will cynically turn tragedy into personal gain, Wright’s attorney will have to resolve how to skate through the corruption pouring in on him.

And the Pakistani teen will have to decide if self-sacrifice is really the only way to get the world’s attention.

Gaghan’s script brilliantly plays with our sympathies and expectations, setting up heroes and villains, and then surprising us as we change our perspective. You may have heard that suicide bombers get a sympathetic treatment here. But Gaghan also lets us see that, yes, these crooked oil guys do have American interests at heart. If we get the oil and the Chinese don’t, then we get to cling to the top rung of the ladder just a little bit longer.

Damon’s character is cynical, but willing to speak truth to power. He may preach high hopes for his new oil sheik clients. But in private? They’re just men dressed in spotless white sheets. And what message does that attire send?

“It’s hot, and I don’t have to work.’

Wright’s attorney has to balance his investigation against fears that he may be somebody’s patsy. And he has to spend too much time with the most ruthless and unscrupulous wheeler-dealers Texas has to offer.

“Corruption,” one (Nelson) bellows, “keeps us safe and warm. Corruption is why we win!”

George Clooney stars in the political thriller Syriana, also featuring Matt Damon and Jeffrey Wright.

The movie is an embarrassment of good character actors, with players like Jamey Sheridan, William Hurt, Amanda Peet (as Damon’s wife) and David Clennon showing up for showy, small turns. It’s a triumph of style, with scenes of overexposed, over-lit Arabia contrasted with the limos, offices and ranches of America, where the strings are pulled.

“Syriana” is a “Traffic” of the oil trade, a “J.F.K.” of current American Middle East policy, full of conspiratorially oily relationships, simplistic policies and cold-blooded murders, tangled up in an untidy story of the way things really work.

“Syriana” is complex, engrossing, involving and depressing. Difficult to absorb, it is also difficult to accept, and it is one of the best films of 2005.