She staggers on to the screen, blood streaming from her face. Some of her wounds are flesh ones, but others are deep. Nobody cares, because her performance is sensational. Her name is truth, and she has taken a terrible beating.

The new thriller All the Money in the World, based on the kidnap of John Paul Getty III in 1973, carries an announcement that it is “inspired by” true events and that its genre is “history”. What does that mean, since some of it is clearly not true? Why not say it is “inspired by lies”, and its genre is fiction? That would be true.

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Likewise, promotion for the latest Churchill movie, Darkest Hour, says that the actor Gary Oldman “is Churchill”. Everyone, including the great man, is made up to appear as in real life. We are asked to treat it as true. Yet it includes a fabricated scene, out of character, in which he chats on the tube with ordinary people, clearly to make him look good. If that is not true, how much else “isn’t Churchill”? Some of it; most of it; or all of it?

Viewers of the TV serial The Crown are also invited to treat its account of the Queen’s life as accurate. Yet the royal historian Hugo Vickers has voluminously documented references that are simply made up – including a Profumo affair connection between Prince Philip and the high society osteopath Stephen Ward. The viewer is offered no guidance as to what is true and what is false. The Crown will now be “the truth” about Elizabeth and Philip, round the world in perpetuity.

Should we care? Hollywood’s apologists claim that documentary fabrication is good clean fun. Since all news is entertainment, why complain if entertainment dresses itself up as news, to give it sex appeal? So what if the Getty kidnap did not end in a corny car chase, or if Prince Philip never had an affair? The biographer Lawrence James loves the new Churchill film because – while it “may not be wholly truthful” – it is “history as it ought to have been … history as a work of art designed to enthral the world”.

I wonder if he would say the same of a fabricated movie glorifying the Germans. We are not told what the Queen thinks of the distortions in The Crown, but I doubt if she would call them “history as it ought to have been”. Why do the producers feel a need to fabricate incidents in the Queen’s life, or Getty’s, or Churchill’s, when the truth is interesting enough? Does Churchill really need lies to bolster his reputation?

The movie business seems to have lost faith in fiction as a way of moving hearts and minds. It craves the authenticity of history to help sell its wares. But fiction depends on the “suspension of disbelief”, on establishing a plausible fake reality, as does Tolstoy’s War and Peace in the historical setting of Borodino. Documentary purports to be journalism, “real” reality. This depends on trust in the veracity of the narrator.

The Getty film was spoiled for me because, at every turn, the storyline veered from apparent history into obvious fantasy. Fact and fiction tumbled over each other until I lost faith in what I should be disbelieving.

Facebook Twitter Pinterest ‘Among Washington dramas, I preferred The West Wing. I knew it was fictional.’ Photograph: NBC/Getty Images

That is why, among Washington dramas, I preferred Washington Behind Closed Doors and The West Wing, rather than All the President’s Men and Oliver Stone’s JFK. I knew the former were fictional, while the latter pretended to be factual, but only up to a point. I admired Steven Spielberg’s Schindler’s List, because I know he assiduously checked his evidence. I enjoyed Frost-Nixon when told it, too, was accurate.

I was trained as a journalist to respect evidence – however inadequately – because journalism must hold the fort of truth until the historians arrive. Errors we may commit, but deliberate falsification is wrong, and we know it is. That is why the west used to ridicule Russian propagandists – and still does – for making up news and distorting history. It is why we attack Donald Trump for doing likewise.

I am therefore glad to feel uncomfortable at seeing lies dressed up as truth. Believing what we read and see in newspapers and books or on the screen is not a casual preference. However subconsciously, we rely on it. We need to trust those who write, edit, record and film what purports to be the truth, because we have no alternative.

The problem is not confined to cinema. The latest account of Trump’s presidency, Michael Wolff’s Fire and Fury, is crammed with allegedly overheard second- and thirdhand quotes, often highly insulting to named individuals. Trump, hardly impartial, says half of them are lies. A BBC reporter remarked that this depiction of Trump’s White House is devastating, “even if only half of them are true”. That surely depends on which half. I could say the same of BBC news reports, but don’t – because I expect all of them to be true.

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That pillar of journalistic rectitude, the New York Times, used to have a rule banning “unattributed derogatory quotes”, except where the source was specifically checked and revealed to the editor. Those days are over, in Britain if not America. I trust Wolff’s integrity, but should I trust him to have checked those who pass him malicious gossip, merely because I happen to like the gossip?

How will it be when the book is elevated – doubtless further distorted – to Hollywood status in Trump: the Movie? Much journalism is now made up of unattributed quotes. We have no way of knowing if they are made up, except to trust in the veracity of reporters and editors. On that tenuous base of trust, the entire fabric of our intelligence about the world around us depends.

I am sure historians will one day find time to correct Hollywood’s version of history: they have spent four centuries trying to correct Shakespeare’s. But we cannot all wait that long. George Orwell was not joking when he said that those who control the past control the future.

Documentary movies that deliberately distort history should carry a great big F-certificate, for fiction. When they punch truth in the face, that is what they are doing: lying.

• Simon Jenkins is a Guardian columnist