Mercilessly complicated thriller about oil, politics, money, terrorism, and how they all relate. At the core of this patchwork quilt of a story is a merger between two major US oil companies, a squabble over the rights to oil drilling in Kazakhstan, a conspiracy to "liberate" Iran, and a plot to assassinate the heir apparent to an anonymous oil-rich nation (Star Trek: Deep Space Nine regular Alexander Siddig – nice to see him landing a good role).

Leading the large, jumbled cast of characters is George Clooney as a rumpled CIA assassin, Matt Damon as an ambitious financial adviser who befriends the aforementioned heir, and Jeffrey Wright as a corporate lawyer whose job it is to find – and then bury – any corporate malfeasance in the oil company merger.

I must confess, even while paying strict attention (for Syriana is never boring), that I got lost somewhere along the way. Is Wright's character doing the right thing? Or is he doing the wrong thing while believing he's doing the wrong thing? Or is he doing the wrong thing for the right reasons? Or the right thing for the wrong reasons? Help! And his is not the only character whose intentions I remain confused about. For example, could somebody please tell me who Christopher Plummer's character is, and what he wants? He seems to be the key connection between all the various subplots, and yet there's something murky about his motivations.

Sure, the corrupt American oil tycoons are indisputably Syriana's bad guys, but which one are we supposed to hate the most? Or does it even matter, since the real villain is ultimately the West's thirst for oil? By the end I felt like I needed to read the Cliff's Notes version of the film, which is especially frustrating as this is an urgent, intelligent work that feels impeccably authentic, down to the smallest detail.

If you're up to the task of keeping up with its byzantine storyline, Syriana is a rewarding experience, a unique look at America's dependence on oil and the price that the world pays – in money and in lives – for this dependence. The cast and direction are first-rate (writer/director Gaghan covered similar territory with his script for Steven Soderbergh's Traffic, which less successfully blended multiple storylines in its depiction of the drug trade), as are the production values. Cynical though it may ultimately be, Syriana is a meaty film for smart adults that probably needs to be seen more than once in order to be fully understood. Only its recurring motif of parallel father-son relationships feels undeveloped and even unnecessary.