Unlike some friends, I can enjoy a good movie as a work of entertainment without taking offence at the politics of its star. I'm happy to cheer on John Wayne as he takes his horse's reins in his teeth and mows down opponents in True Grit without thinking of his pro-McCarthyite stance. And I can watch Jane Fonda's beautifully judged performance in Coming Home without spitting at the screen because she once sat astride a Vietcong anti-aircraft gun. Same with Vanessa Redgrave. I admit, however, the Mel Gibson case could test my ability to prioritise the song over the singer.

Political movies usually elicit visceral feelings regardless of artistic merit. I include in this category movies with a strong social message as well as those whose stars have controversial views. People come with ready judgements even before they've seen the picture. Filmed political biographies are even more likely to anger either side, particularly when the subject - as in the case of Richard Nixon or here, George W Bush, is hated by vast swathes of the audience. Ironically, Oliver Stone's new movie - W - is likely to shatter the preconceptions of supporters and detractors alike. It might even end up pleasing no one, at least in the sense that it almost consciously avoids pandering to either constituency - ie, the "Bush is a retarded cowboy" school or the "Bush is a fundamentally decent man" school.

In the words of actor Richard Dreyfuss (who portrays vice-president Dick Cheney in the movie), this is a "shockingly empathetic" portrait of US president Bush that will have leftwingers claiming that Stone - traditionally a flame-throwing rebel against the political establishment - has either succumbed to premature dotage, been swayed by inexplicable personal sympathy for Bush or simply gone overboard in a bid to be even-handed. Whatever the reason, Bush-whackers, hoping to witness an evisceration of their favourite punchbag politician in W, may be dismayed to find that they leave cinemas with a grudging respect for him. They may even quite like the guy.

Misspent youth
As portrayed by Josh Brolin, the young Bush is an uncultured vulgarian ne'er-do-well, chewing beer bottles and swigging Jack Daniels as he drifts between parties and floozies. He's also a perpetual disappointment to Bush Senior, depicted as a principled and proud patriarch by James Cromwell. "Who the hell do you think you are, a Kennedy?" shouts Bush Senior when his drunken son lurches home after crashing his car into the garage. Dubya's early days are well chronicled: drunken revelry with his fraternity gang, botched attempts to hold down manual jobs, a misspent silver-spooned youth in the shadow of his rich and successful father.

Salvation only comes the morning after his 40th birthday, when Dubya, nursing yet another hangover, decides to forswear the booze in favour of the Christian "light". His parents, delighted at their son's sobriety, are dumbfounded when he declares his intention to challenge Democratic incumbent Ann Richards for the governorship of Texas in 1994. It's clear that brother Jeb Bush (then nursing ambitions to become governor of Florida) was the favoured son, the one for whom George and Barbara Bush (Ellen Burstyn) nurtured the highest hopes. Even the fictitious evangelical Earle Hudd (Stacy Keach) does a double take when Bush interprets his political ambitions as a calling from God. He doesn't try to dissuade him from running for office but you sense he'd like to.

The movie oscillates seamlessly between the first term of the Bush presidency and his early years. Essential to Stone's premise is that Dubya noted the failures - as he perceived them - of his father's presidency. Heeding those lessons, he's determined not to be "out-Bibled" or out-gunned by anybody. But what was the message of Bush Senior's one-term presidency? That's an open question. Ironically, George HW Bush faced criticism from both sides, from those who felt he had concentrated too much on foreign policy issues - "it's the economy, stupid" became the left's standard lexicon - as well as those to his right who felt that his supposed "failure" (or judiciousness depending on one's point of view) in not ousting Saddam cost him the 1992 election.

Comparing father and son
To my mind, Bush Senior (unlike his depiction here) always looked uncomfortable in the White House, somehow unsuited to the top position, especially on the domestic front. Witness his constant insecurity over press attacks on his alleged indecisiveness, his U-turn on a "no new taxes" pledge and his clumsy speech-making. For all his qualities as an international statesman - and Bush Senior certainly deserved credit for not "dancing" on the Berlin Wall when it fell in 1989 - he was somehow less charismatic than his son. You sensed a decent but unpersuasive man, perhaps lacking inner self-confidence. Dubya, on the other hand, has always come across as strong in the self-confidence stakes and certainly far more conservative than his (more internationalist) father. In the movie, it's Dubya who urges his father to nail the latter's opponent in the 1988 presidential race, Michael Dukakis, by running the controversial Willie Horton* ads. When Bush Senior loses to Bill Clinton (and is seen crying in the film - is this really possible?), his son remonstrates with him for not going all the way to Baghdad.

The September 11 terrorist attacks (not shown in the movie) give Bush's presidency a meaning. Surrounded by some of the staff who served his father, Bush is seen as gradually goaded into war on Saddam by chief "villain" Dick Cheney (Dreyfuss), who unabashedly makes the case for geo-strategic domination of the Middle East and, of course, control of the region's oil supply. He is a kind of (male) Lady Macbeth, spurring his boss on.

"Your father was a decent and honourable man but he made the wrong decision," Cheney tells Dubya apropos Saddam. The circle of serpents (if you follow the Stone line) includes hawkish secretary of defence Donald Rumsfeld (Scott Glenn) and deputy chief of staff Karl Rove - a wonderfully snake-like performance from Toby Evans. Secretary of state Colin Powell (Jeffrey Wright) is portrayed as an earnest opponent of the Iraq invasion from the outset. But he eventually comes round in the name of collegiate/collective responsibility to make the case for war before the UN, albeit in a tangibly uncomfortable presentation.

Bush himself is seen to genuinely believe that Saddam did have weapons of mass destruction. When, following the invasion, they prove elusive, he berates Cheney for faulty intelligence briefings.

If weapons of mass destruction were the raison d'etre for Bush's decision, then it's an enormous failure (note Bush's recent refusal to reveal if he would still have gone to war if he'd known that Saddam was bluffing) but, ultimately, it was his alone. Was he trying to avenge his father's election defeat, the so-called unfinished business that dogged his father's presidency? Stone hedges his bets, in a way giving Bush the benefit of the doubt. We are led to believe that Bush is not so immoral as to wage war for the sake of it - or to "avenge" his father - but neither is he one to reconsider in the wake of residual doubts and lack of evidence. Perhaps he should have been more meticulous before putting troops in harm's way.

Fatally - and even his supporters would agree - Bush had little sense of the practical repercussions of decisions. Never is this shown more clearly than over Guantanamo Bay. When Cheney presents him with a dossier authorising unusual methods of "prising information" out of detainees, Bush replies, grinning, "We don't do torture here." Cheney outlines the grisly methods that could - "legitimately" - be used to interrogate suspects. Bush cracks a joke: "Sounds like my frat days," he says in between stuffing his face with food - unpleasant enough to watch in real life but even more off-putting on a giant screen.

Bumptious Bush
Stone's 43rd president is a simple man, not a simpleton as such, but someone out of his depth in the presidency, elevated beyond his ability and lacking the intellectual rigour required for the job. He runs his office with a kind of streamlined efficiency, a delegator rather than a scrutiniser. Fatally, he's never one to unearth an object and see what lies underneath.

Brolin captures Bush's strangely bumptious manner and purposeful swagger but - and perhaps this is a flaw in the script - reveals little of his motivation other than a guilt complex for his wayward youth and a nagging feeling that he failed his father. But this is mere conjecture: in real life Bush is very secure, over-secure perhaps in ways that make him impervious to reality. Sometimes he's been unaware when firmness lapses into mean-spiritedness, as with his immature imitation of death row inmate Karla Faye Tucker's ** plea for clemency when he was still governor of Texas. His judgement was frequently poor. Take his premature declaration of victory after the Iraq War, his misplaced trust in Russian president Vladimir Putin and his condescending treatment of British prime minister Tony Blair - "Yo Blair" - famously caught on a hidden microphone in 2006.

Shockingly for some viewers, however, Bush is neither bad guy nor a laughing stock. He lacks the stature to be a tragic hero or a magnificent villain. Stone's Richard Nixon, on the other hand, a tour de force from Anthony Hopkins in the 1994 biopic, was altogether more Grand Guignol.

Hopkins' Nixon was a neurotic and sweating Machiavellian prone to sharp mood swings, paranoia and ferocious outbursts of temper. Stone pulled no punches with his depiction of Nixon; by the movie's conclusion, the White House is a bunker of recriminations inhabited by an embattled drunk. So, the obvious question is why did Stone, a committed liberal who loathed Bush and all he stood for, go overboard to be "fair" here? Perhaps, simply, mindful of his reputation as a Bush-hater, he felt obliged to pre-empt accusations that he was motivated purely by animus or vindictiveness.

Significant events are omitted from the movie, some flattering to Bush and others to his detriment. The former would include his sterling defiance at Ground Zero after 9/11. In the latter category would be his initial dazed reaction to the attacks while in a school classroom, and his mismanagement of Hurricane Katrina. Of course, a conspicuous black mark against Bush is that, although he never made a direct connection, it's clear that he sowed the idea in Americans' minds that Saddam Hussein and Al-Qaeda were somehow linked.

Ultimately, Stone seems to blame the forces behind Bush more than the man himself. Oil is, of course, the number one reason cited by critics for his decision to go to war. Perhaps also - to be generous - there was Bush's genuine belief in the so-called domino effect of spreading liberty, that somehow a free and democratic Iraq would become the benchmark for an (envious) Arab world. Only time will tell if that comes true. But on that will hinge historians' view of George W Bush's presidency. Meanwhile, as in the movie's final scene, Dubya will be alone in the baseball ground waiting for the final ball to be returned. It could be a long haul. 

* Willie Horton (b 1951), a convicted felon released on a furlough programme by then-Massachusetts governor Michael Dukakis. While released, he committed armed robbery and rape, a notorious case that was used by George HW Bush to criticise Dukakis in a series of controversial television advertisements.

** Karla Faye Tucker (1959-1998), a convicted murderess who was executed with a lethal injection.