When we first met Jason Bourne (Matt Damon), he was unconscious and afloat in the Mediterranean, with bullets in his body and bits of memory lodged like shrapnel in his mind. Since then, Bourne, the amnesiac ex-CIA man, has been all at sea, searching for his lost self. The latest film promises to answer the question: who is Jason Bourne? Is he a killer who will always kill or a good man capable of redemption?

Watching it, I realised Bourne has undergone one of the most bizarre transformations we’ve seen in any character; from CIA assassin, a perfect killing machine, he has ended up a Guardian-reading liberal. Then again, the last two Bourne films have been directed by Paul Greengrass, the left-leaning director of Bloody Sunday and other works for television, such as The Murder of Stephen Lawrence. His Bourne has been severed from his cold-war origins and ended up as the John Rambo of the liberal intelligentsia. Rambo, you will recall, was another brilliant killing machine who was betrayed by his masters (the US army) and went after them when they came after him.

This is a great and liberating day for liberal-kind. For them, spy heroes have always been suspect: Bond was too much of a sexist, Schwarzenegger (True Lies) too right-wing and Vin Diesel (xXx) too dumb. But Bourne allows liberals to enjoy all the forbidden pleasures of the espionage block-buster: they can see him kick ass, break necks, smash faces and shoot fellow human beings, and not complain about civil liberties because the victims work for the CIA. Bourne is the perfect liberal hero – he doesn’t have a fantastic secret-agent body, a tuxedo or a taste for martinis and one-night stands. He is fluent in five languages, drives brilliantly in any city and, as we see here, even reads The Guardian. More important, he blames the system for his sins and is consumed with liberal guilt for what he has done. Perfect.

It’s a story in The Guardian, by an investigative reporter, Simon Ross (Paddy Considine), that sets the action in motion. Bourne reads Ross’s exposé of the CIA and the secret black ops they ran, and finds a mention of himself. He wants to find Ross so he can interrogate his source, in the hope of finding out about his past; the CIA want to find Ross so they can kill him before he discovers anything more about what they’ve been up to. (Might that look a little suspicious?) They want to kill Bourne, too, because they suspect he is the one giving Ross the information.

Post9/11, things have become rather paranoid at the agency. There is a new man in charge of dirty deeds, Noah Vosen (David Strathairn). He runs a secret programme called Blackbriar, which involves rendition, assassination, the usual illegal stuff. As far as Vosen is concerned, anyone who poses a threat should be terminated. Pamela Landy (Joan Allen), who has been sent to help Vosen find Bourne, tries to convince him that Bourne is no threat. But fear is what fuels Vosen’s power.

So, the new Bourne film follows the structure of the old ones: they set out to get Bourne, Bourne sets out to get them. The action spreads across Moscow, London, Spain and Tangier. As usual, there is no foreign exoticness on display. Ordinary streets and homes provide the setting for car chases and hand-to-hand combat. Greengrass keeps it real and raw.

This time, he has outdone even himself. At times, the film seems to have been shot by a hyperactive child having an epileptic fit – the handheld camera zooms in and out of shots, swirls, spins, shakes; things go out of focus, coherence collapses in a frenzy of furious editing. Meanwhile, John Powell’s brilliant musical soundtrack provides the backbeat to hold it all together. You are left feeling disorientated, car-sick and excited.

Although, at its best, this is a powerful and visceral piece of cinema, the vital quiet scenes aren’t up to scratch. Particularly disappointing are the verbal battles between Landy and Vosen. Here are two excellent actors, but their encounters don’t have the fire we saw in the second film’s scenes between Allen and Brian Cox. And for all the fast and furious cinematography, Greengrass can’t hide the fact that the screenplay falls into a familiar pattern. We even get the same kind of scene: Bourne arrives in a new city; Vosen shouts at his staff commands such as, “Okay, people, I want his calls, his contacts traced and his every move followed”; keyboards click furiously as another assassin is ordered to kill Bourne.

I’m not sure the film really answers the question of who Bourne is with any conviction or finality. Nor am I convinced Bourne fans will rush off to see it because they’re desperate to find out who he was in his former life. This is an espionage action block-buster, not a meditation on the mysteries of the modern self; its primary function is to deliver the visceral thrills of car chases, shoot-outs and fight scenes. This it does with an energy and inventive-ness that’s been missing from the spy genre for ages. Even those of us who usually hate this sort of thing have to admit that it’s pretty remarkable entertainment.

12A, 120 mins

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