Eastwood stepped in when Spielberg decided he couldn't deliver American Sniper with the budget on offer. It's difficult to imagine Spielberg's take on this subject, which benefits from the less stylistic agenda of a director like Eastwood.

The movie is an adaptation of the memoir of Chris Kyle, played here by a beefed up but mellowed out Bradley Cooper, a Navy SEAL sniper who, prior to his death at the hands of a disturbed fellow veteran, claimed to have notched up 255 kills, 160 of them officially confirmed. With his outspoken hatred of his enemy, to some Kyle was a hero, some a serial killer, and a mix of both to others. His path begins, like the rebooted Jack Ryan film series, with his viewing of a terrorist attack on TV, prompting himself and his younger brother to join the military.

Trained in rifle skills by his father, Kyle quickly establishes himself as an expert marksman and is assigned the role of sniper when sent to Iraq at the outset of that extended campaign.

Perched upon high, his job is to scour the area below for enemy threats to his fellow soldiers at ground level. His first victims are a woman and a young boy attempting to hurl a grenade at US troops. The hits quickly rack up, earning Kyle "legend" status among the military.

Eastwood chooses to show us Kyle's kills as the sniper himself viewed them - through his rifle scope. It has a strange, contradictory effect of both placing us in Kyle's position and simultaneously distancing us from the act of violence. There is one kill that crucially isn't presented in this way, as Kyle himself moves his eye away from the scope after firing. It's a killing that Kyle has a personal investment in, and so wants to witness it without the protection of the glass of a scope.

American Sniper is a frustrating watch, as it should be, reflective as it is of a highly frustrating situation. The movie has a villain in the form of Abu Musab al-Zarqawi, but there's no final confrontation, instead the focus is on one of his foot soldiers, a Syrian sniper who carries an Olympic medal for marksmanship. Eastwood presents us with some despicable acts, played out in brutal fashion, but the audience is never given the vengeance it desires.

Despite having a wife and kids back home, Kyle is most comfortable when in Iraq, and so is the film itself. The Stateside scenes are a collection of relationship clichés, with Miller's put upon spouse espousing hackneyed lines like "When you're here, you're not really here." The most effective moment of Kyle's difficult home life feels like a holdover from Spielberg's draft, cleverly using a TV set in what feels like a nod to Poltergeist.

Cooper delivers a career best performance in the role of Kyle, beautifully under-playing the part and effectively capturing the frustration of balancing a sense of duty with a belief that no end game is in sight. The extra brawn he carries allows his face to shrink into his heft, his muscle a mask for the feelings he can't express.

In portraying a contentious figure without resorting to demonising or valorizing Kyle, Eastwood has crafted an ambiguous portrait of a figure who in an ideal world wouldn't exist. Not bad for an 84-year-old journeyman.

3.5 out of 5