In early, silent westerns it was easy to tell the good guys from the bad. Baddies wore black hats and didn't shave. The heroes had white hats, and obviously possessed razors too.

Ken Loach's Palme D'Or winner The Wind That Shakes the Barley offers equally unsubtle cues for anyone who might find the politics of its subject, early-1920s Ireland, a bit confusing. The villains wear uniforms, have English or Scottish accents, and are always shouting and swearing a lot. The good guys wear civilian clothes and speak very softly, almost whispering, without any rude words. They have Irish accents – mostly Cork ones, though with a slightly uneasy mixture of regional cadences.

Halfway through, however, the goodies' side splits, and half the erstwhile heroes become villains. No danger of the viewer getting confused by this, though: Ken Loach gives a few gentle hints about who's who. The new bad chaps all put uniforms on, and they start shouting all the time (though they still don't swear). Another subtle clue is that in both halves of the film, only the good side includes any women.

This is not, then, what you might call a complex, politically or morally nuanced film. Nor does it offer any great surprises to anyone at all familiar either with the nationalist version of modern Irish history, or with Loach's previous work. Indeed Wind's storyline, characters, and political message are all quite startlingly similar to those in one of the director's previous historical epics, Land and Freedom (1995), set during the Spanish civil war (1936-39).

In some ways, its simplicity and predictability make the film all too easy to mock. Yet the pre-release reaction in several quarters, especially conservative British newspapers, has been outraged rather than teasing – even what Loach himself has, not unreasonably, called "amazingly vitriolic" personal attacks.

Stephen Howe is professor in the department of historical studies at Bristol University. His most recent books are Afrocentrism: Mythical Pasts and Imagined Homes (Verso, 1998), Ireland and Empire: Colonial Legacies in Irish History and Culture (Oxford University Press, 2000), and Empire: A Very Short Introduction (Oxford University Press, 2002).

Also by Stephen Howe on openDemocracy:

"Munich: Spielberg's failure"
(January 2006)

"Mad Dogs and Ulstermen: the crisis of Loyalism"
(September 2005)

"Boycotting Israel: the uses of history"
(April 2005)

"Israel, Palestine, and campus civil wars" (December 2004)

"The death of Arafat and the end of national liberation"
(November 2004)

"An Oxford Scot at King Dubya's court: Niall Ferguson's 'Colossus'" (July 2004)

Simon Heffer in the Daily Telegraph accused Loach of hating Britain and making "repulsive" films while sponging off the taxpayer. The Sun claimed the film was "designed to drag the reputation of our nation through the mud". The Independent said it would "come across like a recruiting campaign for the IRA". Ruth Dudley Edwards in the Daily Mail called it "old-fashioned propaganda" and a "melange of half-truths'" She accused the director of portraying the British as "sadists and the Irish as romantic, idealistic resistance fighters".

On that view, not only Loach himself but almost everyone else involved in the film – plus of course the Cannes jury which awarded it their top prize – are motivated by ignorant, sentimental, kneejerk sympathy for Irish Republicanism, shading into apologetics for IRA murderers past and present, and by an equally thoughtless anti-British bigotry. One might note, though, that very few of those newspaper pundits can have seen the film before attacking it.

Loach himself thinks his critics are motivated by "deep-seated imperialist guilt". He told guests at Cannes that: "Our film, we hope, is about the British confronting their imperialist history and maybe if we tell the truth about the past, we will have the truth about the present." By that he meant, he made clear, the parallels he sees between 1920s Ireland and Iraq today.

Almost nobody, it seems, is interested in arguing over whether Wind is artistically compelling – bluntly, it isn't – but in its political implications and historical accuracy. How does it hold up on that front?

A distorting lens

Almost every incident of British military brutality depicted in the film has parallels in events which took place – or at least were alleged – in Ireland, mostly in rural west Cork, in 1919-21. Random, unjustifiable killings, torture and abuse of suspects, forcible head-shaving, racist insults (and yes, lots of profanity and four-letter words, which sometimes seem to have shocked pious Irish countryfolk more than anything else): all these certainly happened.

What is far more contentious is whether any of that – except the swearing – was commonplace, routine, or typical of British behaviour as the film implies, or how far it was sanctioned by political or military leaders. Many historians argue that such incidents were rare, isolated, unauthorised and indeed were denounced, sometimes severely punished, by the authorities. Wind, on that view, doesn't entirely invent anything, but does mislead by selection and implication.

On the other side, the film's images of IRA behaviour show the guerrillas killing only with great reluctance and for very good reasons. In a climactic ambush scene, British forces are wiped out in fair fight – though there's a strong albeit endlessly-disputed case for thinking that in the real-life ambush on which it's closely based, at Kilmichael in County Cork, the IRA finished off their opponents after they'd surrendered or as they lay wounded.

In another highly-charged scene, hero Damien (Cillian Murphy) and his friends execute two men who'd informed on them. They do so only after making quite sure the two are guilty, and then trying to bargain for their lives against those of IRA men threatened with execution by the British. They agonise over thus taking helpless men's lives, especially that of a young local lad. How, they ask, can they kill "one of our own", even if he'd betrayed them? Even when the IRA attacks a police station, it's not to hurt anyone, but just to warn the police they must stop ill-treating prisoners!

Again, there are close historical parallels for all those incidents, or at least stories very like them in IRA memoirs and other accounts. But again the film could be said, by selection and omission, to present as typical things which were anything but. The IRA killed hundreds of policemen, and alleged spies and informers. In almost all such cases there was no warning, no "trial", no attempt to bargain for their lives. Very few of the "informers", it seems, were guilty of anything at all. Vagrants, homeless men, supposed sexual deviants, and (perhaps most disturbingly) local Protestants made up a very high proportion of the victims. Far from killing "one of our own" being a rare event and a cause of profound soul-searching among the IRA, a majority of those they killed were fellow Irishmen and women, their own neighbours.

"Proper little battles" with two organised groups of armed men fighting it out, like Kilmichael or the related scenes in the film, were very rare. Most of the killings were straightforward assassinations of helpless, unarmed people; and these go entirely undepicted in Wind. The IRA campaign of the 1920s was less indiscriminately murderous than in the more recent Northern Irish "troubles", but it was a difference of degree more than of kind.

Yet political distortion is maybe more blatant in the film's second half, as the Republican movement splits over whether to accept a compromise treaty with Britain, and descends into civil war. The division is prefigured in a confrontation at an underground Sinn Fein law-court, where it has to be decided whether to believe a local money-lender or a poor old woman who's in debt to him.

The conservative, militaristic types among the Republicans support the businessman: they need his help to buy guns for the cause. The idealists and socialists (and all the women) back the old lady. As an older IRA man – who'd already been shown, sharing a jail cell with Damien and expounding James Connolly's socialist philosophy – movingly proclaims to the court, it's no good fighting for national independence if it's not accompanied by a battle for social justice.

Again, there were such scenes and such debates within the Irish nationalist movement. There were some (though rather few) socialists in their ranks. But Ken Loach then depicts the schism over the treaty, and over whether to accept Ireland's partition, as following just the same lines. The anti-treatyites, from whom the modern IRA claims direct descent, are the idealists, the socialists. Their opponents – who, as noted, promptly don ex-British Army uniforms and start shouting a lot – are social reactionaries as well as traitors.

Here, Loach's film totally misrepresents the far more complex lines of division which really occurred. He does so in ways familiar from his long-held political views: the true, pure nationalists must also be true socialists. On the other side are the pro-imperialists, the compromisers and betrayers, the Tories, the Catholic church (in another emblematic scene a bullying, authoritarian, reactionary priest upholds the treaty and calls its opponents communists) and, of course, all the people who shout. It's a travesty of history. Early socialists in many countries used to warn "don't paint nationalism red!" But that is exactly what Loach does here, with dispiriting if not disturbing implications for his view of Ireland, or of Britain, today.

From cinema to seminar-room

The film's title comes from a dreadfully schmaltzy, and also bloodthirsty, ballad about the 1798 Irish rebellion. The song's sentiments actually all too well mirror the beliefs of many of the rebels of 1916-22 and of the anti-treatyites of the ensuing civil war. Far from being Loach's radical socialists and internationalists, most of them had little ideology beyond that derived from a romantic, culturalist, separatist, sometimes necrophiliac brand of nationalism. Such a form of Irish nationalism (never, of course, the only one available) does not need cinema to turn it into kitsch: it was built into its very foundations and well encapsulated by those dreadful songs and the myth of blood-sacrifice they transmitted. It's a great pity Ken Loach has fallen for all that.

This is not, even so, a dishonest film, nor a stupid one. It does not, even by implication or selection, lie. It distorts, to be sure: it bends and filters. How can any imaginative rendition of historical events avoid doing so? It's much debated whether even "proper" academic historians can ever avoid a high degree of selectivity and partiality.

And if its political message is crude and simple, it's certainly no more so than with most "historical" or agitprop cinema treatments of Irish or any other conflicts. Indeed, compared to the average Hollywood effort, or to other films which have (with some justice) been labelled "anti-English" or "anti-British" like Mel Gibson's ridiculous Braveheart and The Patriot, Loach's is a strikingly intelligent effort. It's also, though, a strangely unengaging, emotionally flat one. It is a fair guess that in the longer run – as in the pre-release polemics (and as in this review) – Wind will continue to be more debated by historians than it will be enjoyed by the average filmgoer.

Ken Loach's Ireland: suggested further reading

Ken Loach's film clearly draws heavily on several IRA memoirs of the era, especially Ernie O'Malley's On Another Man's Wound and Tom Barry's Guerrilla Days in Ireland. Wind's hero, the young medical student Damien, is loosely based on O'Malley (though the latter was a Dubliner rather than a Corkman).

Originally published in 1936 and 1949 respectively, both can still be found in more recent reprints. There's also a fine biography of O'Malley by Richard English (1998).

On the west Cork events around which the film is mostly centred (it was also mainly shot there), the most important, contentious and damning account of the IRA's campaign is Peter Hart, The IRA and Its Enemies (1998). Meda Ryan, Tom Barry: IRA Freedom Fighter (2003) is a counterblast defending the reputations of her local heroes. The ensuing controversies have raged on and on, up to and including May-June 2006, and Loach's film is already feeding into them. Some of this can be tracked (albeit from a mostly anti-Hart angle) on the excellent indymedia.ie website.

The film's theme of two brothers taking opposite sides in the civil war probably owes something to another west Cork story, that of the Hales family. Among many histories of the Irish civil war and the surrounding politics, Michael Hopkinson's Green Against Green (1988) is a fairly trustworthy introduction.

– Stephen Howe