Modern democratic politics sometimes seems to have been reduced to a game of hunt the hypocrite. Politicians who do not practise what they preach are an affront to democratic sensibilities, because they seem to be setting themselves apart from the rest of us, obeying their own private rules. The same goes for politicians who do not tell us what they really believe (which is the classical definition of a hypocrite - someone who "masks" the real person underneath). We want our politicians to be sincere, so that we can know they are not hiding anything from us. So all politicians are ceaselessly probed for the little inconsistencies, double standards, concealments and obfuscations that indicate a hypocrite, by opponents who know what damage that label can do. Almost all negative political advertising is essentially an attempt to show that a rival candidate for office is not as good as he or she pretends to be. And that's why negative advertising works.

This obsession with sincerity, and loathing of bogus sentiment, has benefited some politicians and damaged others. George W Bush, Tony Blair, John McCain and Barack Obama have all taken advantage of the premium we place on politicians who seem to be comfortable in their own skin, and with their own values; Al Gore, John Kerry, Gordon Brown and Hillary Clinton have all suffered from appearing to hold something back, so that we can never be sure who it is we are dealing with. Brown in particular is paying the price for his inability to come to terms with the new confessional politics. People want to know who he really is, but if what he is really is a cautious and reserved politician who plays the percentages, then the public don't want to know. So he is forced to tour the daytime-TV sofas trying to show his human side, and ends up revealing only how uncomfortable he is with the politics of self-revelation. His caution and his constant calculation make him look like a man in a mask - the classic hypocrite with something to hide.

But there aren't really any winners here. The sincere politicians soon find that they too look like people with something to hide, since no one can withstand the scrutiny of the 24-hour news cycle. They also discover that no one can survive without chipping away at the sincerity of their opponents. McCain and Obama want to offer a truth-telling politics that stands above partisan bickering, but they also have to make sure that no one is fooled by the fake versions on offer elsewhere. So the straight-talking politicians, as they allow their proxies to rubbish their rivals, end up looking like hypocrites too.

This dance of hypocrisy and anti-hypocrisy, the endless round of masking and unmasking that is electoral politics, can be profoundly frustrating and debilitating, not just for the politicians, but for all the political commentators who want to escape from it. Most journalists long to take politics to some higher plane of argument, where the truth can be told, yet find themselves reduced to reporting on the name-calling that passes for political debate. Looking for a way out from all this double-talk, they often start looking back, nostalgically, to the one writer who retains a reputation for never having compromised in telling it like it is. Enter George Orwell, the great scourge of political hypocrisy and cant, whose name now acts as a kind of shorthand for integrity in the face of the temptations of hypocrisy.

Orwell has become the patron saint of all those journalists who think most other journalists are no longer up to the job of wading through the bullshit of contemporary political life. "To see what is in front of one's nose needs a constant struggle," Orwell wrote, and this is the dictum that stands at the head of Andrew Sullivan's influential (and passionately pro-Obama) blog, "The Daily Dish", where he lays into anyone (particularly anyone called Clinton) who doesn't match up to Orwell's standards of straight-talking. What writers such as Sullivan love about Orwell is his apparently limitless contempt for obfuscation, euphemism and deceit. Orwell believed that good prose should be like a window-pane, allowing you to see through to the world behind. He also believed that most people talking about politics were simply smearing the window with grimy clichés.

Orwell's loathing of certain kinds of hypocrisy has also made him the patron saint of those journalists who want to defend the war on terror against what they see as the grotesque double standards of its critics. During the second world war, Orwell used to excoriate leftists who would happily criticise Roosevelt and Churchill but wouldn't say a word against Stalin. Replace the first two with Bush and Blair, and Stalin with Bin Laden or Saddam, and Orwell-lovers such as Christopher Hitchens think you have history repeating itself. The leading American neoconservative William Kristol recently wrote an article in which he says that browsing Orwell in an airport store reminded him once again why Democrats in the US may not be fit to govern: their "sniggering" attitude to American failure in Iraq shows that "they no longer even try to imagine what action and responsibility are like".

But using Orwell the anti-hypocrite as a stick to beat up anyone whose political values are not entirely consistent and robust in their defence of freedom is too easy, and it is wrong. Orwell himself was by no means a straightforward anti-hypocrite, and his attitude to hypocrisy is both more interesting, and more complicated, than his present-day champions would have us believe. Orwell does offer us a way out, but only if we stop treating him as someone who can save us from the curse of hypocrisy. Instead, Orwell shows us that the only escape from the most corrosive forms of hypocrisy is to accept that other forms of hypocrisy are unavoidable. He wanted the language of power to be transparent, but that did not mean that he thought either people or the political systems they inhabited should be transparent as well. He also accepted that hypocrisy in politics is invariably preferable to its opposite - an excess of sincerity. There were many forms of politics that Orwell was prepared to countenance in which a kind of double standard, hypocrisy or deliberate concealment was being practised, so long as that concealment had an element of truthfulness about it.

What I am thinking of in particular is Orwell's defence of the various, complicated hypocrisies of being English. Take, for example, Orwell's treatment of two very English writers whose political views he emphatically did not share: Rudyard Kipling and PG Wodehouse. Orwell was willing to stick up for both of them, and in both cases it was because, whatever might be said against them, they were at least to be preferred to those who used hypocrisy as a stick to beat them with.

So, while Kipling's imperialism was repugnant to Orwell - "it is no use pretending," he wrote, "that Kipling's view of life, as a whole, can be accepted or even forgiven by any civilised person" - Kipling himself was not, for a variety of different reasons. First, Orwell felt that Kipling was at least open about his prejudices. He had a world-view that he was willing to defend for what it was, and as such he stood in obvious contrast to those "humanitarian" hypocrites who condemned empire while relying on its fruits to sustain their comfortable lifestyles. As Orwell puts it, in a characteristically belligerent passage from The Road to Wigan Pier

It is so easy to be witty about the British Empire. The White Man's Burden and "Rule Britannia" and Kipling's novels and Anglo-Indian bores - who could even mention such things without a snigger? . . . That is the attitude of the typical left-winger towards imperialism, and a thoroughly flabby, boneless attitude it is . . . For apart from any other consideration, the high standard of life we enjoy in England depends upon our keeping a tight hold on the Empire. Under the capitalist system, in order that England may live in comparative comfort, a hundred million Indians must live on the verge of starvation - an evil state of affairs, but you acquiesce in it every time you step into a taxi or eat a plate of strawberries and cream.

Second, Kipling's prose chimed with a truth about the world, even though it also represented a failure to face up to certain truths: "He dealt largely in platitudes," Orwell says, "and since we live in a world of platitudes, much of what he says sticks." But perhaps most importantly, Orwell felt that Kipling always kept something of his own personal character in reserve, and that there was therefore always more to Kipling than the views with which he was associated. Orwell described this extra something as his essential "personal decency", and he said on Kipling's death: "It is worth remembering that he was the most widely popular English writer of our time, and yet that no one, perhaps, so consistently refrained from making a vulgar show of his personality." Kipling was saved, in Orwell's eyes, by the fact that his writing, for all its robustness (and not least its robustness about power), was not fully self-revealing, in that it did not allow one to see all the way through to the man underneath.

Wodehouse, by contrast, was saved by the fact that the writing was the man - Orwell accepts that Wodehouse was "his own Bertie Wooster". This is why Orwell believed it was absurd to pillory Wodehouse for the mildly treacherous radio broadcasts he made while interned by the Nazis during the second world war. Wodehouse was what Orwell called "a political innocent", someone whose essential stupidity about politics - "his mild facetiousness covering an unthinking acceptance [of the world he inhabited]" - rescued him from the charge of the worst sorts of hypocrisy. Instead, the worst of the hypocrites were Wodehouse's critics after the war, who saw in him "an ideal whipping boy", and used him as a distraction from any attempt to expose the far more extensive collaborations and deceptions that underpinned their own war efforts. "All kinds of petty rats are hunted down," Orwell wrote in his defence of Wodehouse, "while almost without exception the big rats escape."

What Kipling and Wodehouse had in common for Orwell was that there was a kind of integrity to their double standards, though of very different kinds. Kipling deliberately concealed something of himself, but did not seek to conceal the truth about the nature of imperial power; Wodehouse exposed himself, and thereby inadvertently exposed something of the double standards of the system of power in which he unthinkingly believed. But it is also true that what rescued Kipling and Wodehouse in Orwell's eyes was that they did not share the other's vice. The easiest way to illustrate this is to consider what would have happened if their positions had been reversed. It is inconceivable that if Kipling had found himself in Wodehouse's position, broadcasting for the Nazis for the sake of a quiet life, then Orwell would have defended him; there was nothing innocent about Kipling, and therefore there was no way of imagining that he might have been self-deceived in such circumstances. Stupidity might just retain its integrity in the face of totalitarianism, but knowingness never could. Equally, it is impossible to imagine Orwell defending a PG Wodehouse view of British imperialism, because there was nothing innocent about imperialism, and political naivety in that context was always culpable. Kipling could write about empire because he was in no sense naive about it; what made Orwell despair of British imperialism was that it was not on the whole staffed by Kiplings, but by Bertie Woosters.

It is this complicated attitude to hypocrisy that underpins Orwell's most famous discussion of what it means to be English, in the essays published in 1941 as The Lion and the Unicorn, including the one entitled "England, Your England". There are two sorts of hypocrisy described in that essay. The first is the relatively innocent hypocrisy of democracy, which is underpinned in the English case by the sentimentality of the working classes and the stupidity of those who rule them. This innocent stupidity is exemplified for Orwell by the "morally sound" willingness of the English upper classes to get themselves killed in wartime. Even the Woosters of this world, who can't be relied on for much, can be relied on for this: "Bertie, a sluggish Don Quixote, has no wish to tilt at windmills, but he would hardly think of refusing to do so when honour calls." Democracy, for Orwell, is a charade, but the innocence of the English version is what saves it from being a total fraud. "It follows," Orwell writes, "that British democracy is less of a fraud than it sometimes appears. A foreign observer sees only the huge inequality of wealth, the unfair electoral system, the governing-class control over the press, radio and education, and concludes that democracy is simply a polite name for dictatorship." But democracy is more than just a name in England, because the hypocrisy is more pervasive than that would suggest. It shapes and conditions the way that people behave. "Public life in England," Orwell declares, "has never been openly scandalous. It has not reached the pitch of disintegration at which humbug can be dropped."

The image Orwell uses to capture the essence of English public life is of "a society which is ruled by the sword, no doubt, but a sword which must never be taken out of its scabbard". He goes on: "An illusion can become a half-truth, a mask can alter the expression of a face . . . The sword is still in the scabbard, and while it stays there corruption cannot go beyond a certain point." So, he concludes, "even hypocrisy is a powerful safeguard".

But there is another sort of hypocrisy at work in English life, beyond that of democratic solidarity. That is the hypocrisy of empire, and here Orwell tends to side with the foreign observers who detect in English attitudes to their empire a culpable double standard. In relation to their domestic affairs, Orwell believes that foreigners are wrong to write off the English hatred of "militarism" as merely a "decadent" form of hypocrisy. But it is impossible to ignore that, in relation to the politics of empire, English innocence cannot be what it appears. After all, it is in the essence of imperial power that the sword does not remain in the scabbard. The recurring images in Orwell's work that seek to capture the essence of the imperial experience are of the weapon, however blunt and however crude, being unsheathed.

Orwell himself described his personal awakening to the true nature of imperial power as occurring in Colombo harbour, during his trip out to Burma to begin his career as a military policeman. There, he witnessed a native servant, who had dropped a trunk that was being taken on board the ship, being viciously kicked on the backside by a white police sergeant, to the obvious approval of the onlookers. This, for Orwell, was in essence what empire meant: unthinking brutality. But the most memorable of all Orwell's images of imperialism in action comes in perhaps the most celebrated of all his shorter pieces of writing, "Shooting an Elephant". Orwell, in Burma, is called upon to shoot an elephant that is said to have killed a man, in front of a crowd of eager Burmese onlookers. This event, Orwell says, offers a glimpse of "the dirty work of empire at close quarters". And what it shows is that the agents of imperial authority don't know what they are doing; they are merely acting out a part over which they have lost control. "I was seemingly the leading actor in the piece," Orwell writes, "but in reality I was only an absurd puppet pushed to and fro by the will of those yellow faces behind." Orwell did not wish to shoot the elephant, but he felt he had no choice. The white man on imperial duty "wears a mask and his face grows to fit it. I had got to shoot the elephant." The hypocrisy of empire is revealed here as the unsheathing of the weapon by someone who does not wish to use it, and has lost all control of what can be done with it, or even of what it is for, but must go through with his part anyway.

In "Shooting an Elephant", Orwell doesn't exactly come across as Bertie Wooster - he is far too reflective for that - but he is not a million miles away from the world of PG Wodehouse either. Wooster would also shoot the elephant, and though, in his case, it might not cause him any great pangs of conscience, it would also be because he was the puppet, not the puppeteer. The stupidity of the British ruling class, which was their saving grace so far as democracy was concerned, was catastrophic in the context of empire. Kipling, who was neither stupid, nor strictly speaking a member of the British ruling class (he was, essentially, a journalist) at least did not try to pretend that the empire was something it was not. But not even Kipling was able to tell the basic truth about the British empire: that democratic hypocrisy and imperial hypocrisy simply do not mix. Democratic hypocrisy, in Orwell's terms, is saved by the element of self-deception on which it rests, which is what turns the illusion into a half-truth, and keeps the sword in its scabbard. Imperial hypocrisy is rendered self-defeating by that same self-deception, since the sword cannot remain in the scabbard, and will be deployed for the supposed benefit of the people it is being used to coerce, by people who are unable to be honest with themselves about the nature of that coercion.

In a way, it is easy to see what the solution is to this clash of hypocrisies: democracy needs to abandon imperialism, as Orwell was convinced that Britain needed to divest itself of its empire, and to face up to the sacrifices which that would involve. But it is important to recognise that the democracy that abandons imperialism does not abandon hypocrisy: rather, it preserves its own sustainable hypocrisy by ditching the form of power that makes a mockery of it. There is an alternative remedy, of course, which is to abandon hypocrisy altogether. This is what would happen if imperialism jettisoned democracy, rather than the other way around. An imperial order unconstrained by democratic or liberal hypocrisies, in which power can be called by its proper name, in which the sword is always unsheathed because there is never any need to conceal it, is certainly possible. Indeed, Orwell believed, it was not just possible, but prevalent in the world he had come to know, and would be all-pervasive in one possible future world that he was to imagine. Imperialism without hypocrisy is called fascism, and it is one of the distinguishing marks of fascism, as of other totalitarian regimes, that it does not need to be hypocritical. Totalitarians can afford to be sincere about power. It is out of this sincerity that we get a third quintessentially Orwellian image, to place alongside that of the unsheathed sword, and that of the young military policeman stumbling along a road in Burma, armed only with his elephant-gun. The third image is of a boot, stamping on a human face.

Yet it is not only the sincerity of fascism that poses a threat to English hypocrisy in Orwell's eyes; there is also the dangerous sincerity, or anti-hypocrisy, of anti-fascism. Orwell gives an extended glimpse of what this sincerity might look like in a passage in the novel Coming Up for Air, in which the hero George Bowling attends a political meeting, in the period before the outbreak of hostilities between England and Germany, and listens to a speech:

[He was] a rather mean little man, with a white face and a bald head, standing on a platform, shooting out slogans. What's he doing? Quite deliberately, and quite openly, stirring up hatred. Doing his damnedest to make you hate certain foreigners called Fascists. It's a queer thing, I thought, to be known as "Mr So-and-so, the well-known anti-Fascist". A queer trade, anti-Fascism . . . But the grating voice went on and on, and another thing struck me. He means it. Not faking at all - feels every word he is saying. He's trying to work up hatred in his audience, but that is nothing compared to the hatred he feels himself. Every slogan's gospel truth to him. If you cut him open all you'd find inside would be Democracy-Fascism-Democracy. Interesting to know a chap like that in private life. But does he have a private life? Or does he only go round from platform to platform, working up hatred? Perhaps even his dreams are slogans.

This scene foreshadows a better-known scene in a better-known book: the hate session in Nineteen Eighty-Four, in which the crowd is required to vent its fury at the hate figure of Emmanuel Goldstein, and does so in all sincerity, even Winston Smith, who feels the hatred wash through him ("the horrible thing about the Two Minutes Hate was not that one was obliged to act a part, but that it was impossible to avoid joining in. Within 30 seconds any pretence was always unnecessary"). The scene from Coming Up for Air also foreshadows a theme of that later book, which is what it might mean not to have a private life, not to have anything held back or reserved, but simply to be the slogans that one is forced to spout through and through. In such a world, hypocrisy would not simply be valuable, it would in a sense represent the ultimate value, because its precondition is having something to hide. Nineteen Eighty-Four is a description of a world in which hypocrisy has become impossible.

What, though, of Orwell's greatest book, Animal Farm? Isn't this an exercise in the exposure of hypocrisy, rather than the exposure of a world where hypocrisy is impossible? Certainly, Animal Farm seems, at its most literal, to be a litany of hypocrisies: from the double standards of the pigs (changing the commandment from "No animal shall drink alcohol" to "No animal shall drink alcohol to excess", the day after they have discovered the joys of whisky) to the false promises of Napoleon, their Stalin-like leader, and the sanctimony of his speechifying. But at its end, Animal Farm also points towards the end of hypocrisy, as the criteria by which hypocrisy might be judged themselves become unsustainable. The final scene in the book describes the moment when the leading pigs play cards with the humans, with whom they are now happy to do business, and drink whisky, and fight. Their faces, Orwell says, began "melting and changing". He goes on:

Twelve voices were shouting in anger and they were all alike. No question, now, what had happened to the faces of the pigs. The creatures outside looked from pig to man, and from man to pig, and from pig to man again: but already it was impossible to say which was which.

Throughout his life, Orwell was obsessed with masks, including the various masks of power, and the masks worn by those who sought to hide the truth about power. It is this preoccupation with masks that makes sense of one of Orwell's most famous lines, and one of his most misunderstood. In perhaps the last thing he ever wrote, Orwell declared: "At 50, every man has the face he deserves." This does not mean that we deserve our physical appearance; what it means is that we deserve our mask, the face we choose to show to the world, because having lived with it for so long we can no longer claim that it is merely a façade. Here, though, at the end of Animal Farm, is a scene in which no one is wearing a mask, because it is no longer possible to see what there is to mask. Once again, no one has anything to hide, and that is where the terror lies.

Orwell was an anti-hypocrite for whom there were worse things than hypocrisy. He was also an anti-hypocrite who understood how anti-hypocrisy could itself become the vice it was supposed to be rescuing us from. Democrats who sought to confront fascism on its own terms, like "Mr So-and-So the well-known anti-Fascist" in Coming Up for Air, were succumbing to the temptations of sincerity that ideological conflict offers to all its participants. These are the temptations that it continues to offer to this day - no doubt many neoconservatives are entirely sincere in their crusade to unleash the weapons of democracy against Islamofascism, which is what makes their attempts to corral Orwell into that all-or-nothing struggle so unconvincing. As Orwell said in March 1940 of the war then only just begun: "For Heaven's sake, let us not suppose we go into this war with clean hands. It is only while we cling to the consciousness that our hands are not clean that we retain the right to defend ourselves." And as he said in February 1944 of the war whose end was still nowhere in sight: "In the last analysis, our only claim to victory is that if we win the war, we shall tell fewer lies about it than our adversaries." This is not truth versus lies; it is fewer lies versus more lies, or democratic hypocrisy versus the total lie. Indeed, for Orwell, it was the hypocrisy of the English that served to ensure that they were not entirely self-deceived about the moral compromises entailed in confronting a totalitarian ideology; they at least still knew what it meant to have something to hide.

Orwell is an excellent guide to the problem of political hypocrisy, but not in the way he is usually taken to be. He shows us that politics is not about, and should not be reduced to, a choice between sincerity and fakery - seeing it in these terms opens the door to the worst sorts of hypocrisy, or worse still, raw power without the kind of hypocrisy that can keep it in check. The real choice is between different kinds of hypocrisy, and in this context it is democratic hypocrisy, not sincerity, that needs defending. It is all too easy to get frustrated with the messy and murky compromises of domestic politics - as Bush, Blair and their many sincere cheerleaders in the press have done over the past few years - and to look for escape in the cleaner and crisper air of a new liberal imperialism, where politicians and journalists can open their hearts about all the good they want to do. But as Orwell shows us, imperial politics and democratic hypocrisy do not mix and, as Orwell makes clear, this is the point where we have to choose. Political Hypocrisy: The Mask of Power, from Hobbes to Orwell and Beyond by David Runciman is published this month by Princeton University Press (£17.95).

· This article was amended on Thursday May 22 2008. The still from Halas & Batchelor's 1954 animated film Animal Farm, which accompanied the article above, belongs to the Halas & Batchelor Collection and should have been credited to it and to the Bridgeman Art Library. This has been corrected.