WHEN American and British forces leave Iraq there may still be questions about the weapons of mass destruction that were never discovered.

In riveting thriller Green Zone, award-winning British filmmaker Paul Greengrass and actor Matt Damon, pictured, offer their take on the situation.

They were the team behind the hit The Bourne Supremacy and The Bourne Ultimatum films.

Green Zone is based on the book Imperial Life In The Emerald City: Inside Iraq's Green Zone, by journalist Rajiv Chandrasekaran.

The film is a breathless two hours of adrenaline-pumping action and political manoeuvring that places as much emphasis on the emotionally-charged dialogue as the set pieces.

It opens with a deafening bang on March 19, 2003, in Baghdad as Saddam Hussein's trusted general (Yigal Naor), flees his headquarters in the midst of Allied bombing.

Four weeks later, US Army warrant officer Roy Miller (Damon) and his team visit the capital to look for weapons of mass destruction (WMDs).

They draw a blank and Miller voices his frustrations, suspecting bogus intelligence.

A tip-off from a disgruntled local, Freddy (Khalid Abdalla), leads Miller and his crew to a meeting of Saddam's high-ranking advisers.

The general escapes, but another man is apprehended.

Miller uses Freddy as a translator to interrogate the suspect about a notebook with names and locations of the general's safe houses.

Returning to base, Miller delivers the book to local CIA chief Gordon Brown (Brendan Gleeson).

The chief asks for discretion, to Miller's surprise.

Green Zone is distinguished by Greengrass's tour-de-force style and there is no better director of action sequences.

Damon delivers a passionate performance as a soldier with a conscience, who doesn't understand the full extent of the conspiracy.