When future generations study creative works that capture the unsettled spirit of our age, they might easily neglect Bridget Jones 4: Mad About the Boy. The movie isn’t about the historical inflection point that coincides with its release. It doesn’t feature Donald Trump, his vandalism of US democracy or his dissolution of the transatlantic alliance. Such things are not the stuff of romantic comedy. Also, they hadn’t yet happened in 2013, when Helen Fielding wrote the book on which the film is based.

But the lack of intentional allegory doesn’t prevent us projecting one on to the story. Or maybe it was just me, experiencing a sentimental hallucination induced by events outside the cinema. Indulge me a moment (and forgive any plot spoilers), as I explain.

The first three volumes of the Jones diaries are picaresque chronicles of professional and sexual misadventure that resolve themselves in the reassuring arms of Mark Darcy, a human rights barrister: stolid, emotionally reticent, honourable and kind. That on-and-off romance sweeps Bridget from twentysomething anxiety to thirtysomething neurosis; from post-adolescent insecurity to early midlife crisis, unplanned pregnancy and, in the happy ending, marriage.

Allowing for some chronological elasticity (with lags between books being written and adapted for cinema), Jones’s relationship with Darcy unfolds against a political and economic backdrop that hindsight reveals to be exceptionally benign. It is that period sometimes called the Great Moderation: roughly from the fall of the Berlin Wall in 1989 to the global financial crisis in 2007-09.

Democracy sprawled eastwards across Europe. Captive peoples were liberated from communist dictatorship. The dissolution of the Soviet threat generated a “peace dividend” for western governments, permitting a diversion of budget resources from defence to social spending.

There was a viable Middle East peace process. In 1993, Yitzhak Rabin and Yasser Arafat shook hands over the Oslo accords on the White House lawn. Apartheid was dismantled in South Africa, which held its first free, multiracial elections in 1994. The Good Friday agreement brought peace to Northern Ireland in 1998. The UK was then well into an economic boom that had another nine years still to run.

London was basking in its status as capital of “Cool Britannia” – a powerhouse of art, music and self-congratulation. This was the context in which Bridget Jones’s diary first appeared as a weekly newspaper column in 1995. Her avid readership was the same generation that hit their young adult stride in that bright springtime of liberal metropolitan complacency.

Jones was not very political, which made her an eloquent exponent of the zeitgeist. “It is perfectly obvious that Labour stands for sharing, kindness, gays, single mothers and Nelson Mandela,” she wrote on the eve of Tony Blair’s 1997 landslide election victory. The Tories were “braying bossy men having affairs with everyone shag shag shag left right and centre and going to the Ritz in Paris then telling all the presenters off on the Today programme.”

We know also from a one-off column published in 2019 that Jones was a remainer in the Brexit culture wars. To break the legislative deadlock in parliament, she proposed that Queen Elizabeth, David Attenborough and Joanna Lumley join forces, urging the nation to reconsider the referendum question.

It makes perfect sense that the love of Bridget’s life should be a distinguished lawyer who battles global injustice. It was a match made in the late 20th century, when human rights were a byword for all that was virtuous in western democracy. A career dedicated to their defence was the obvious device for a comic novelist wanting to signal intimidating levels of moral uprightness in a character. (It is often said that Darcy was modelled on a younger Keir Starmer. Fielding acknowledges uncanny likenesses in profession and manner, while insisting they are coincidental.)

In the opening minutes of Mad About the Boy, we learn that Darcy is dead. He was killed in the line of duty, of course, on a humanitarian mission overseas. His widow is struggling to restart her life and raise two children alone.

If, like me, you succumb easily to cinematic schmaltz, this is already an affecting scenario. What I found unexpectedly poignant was the thought that Darcy’s untimely death also functions as a metaphor for the demise of political certainties that defined the world in which Bridget Jones’s generation came of age. Her heartbreak is a parable of political bereavement, describing liberal angst at the sudden unravelling of institutional and legal norms underpinning European security. (Plus sex and jokes.)

In the week that the movie was released, the US president reached over the heads of his country’s former Nato allies to embrace Vladimir Putin. He sketched the outline of a deal to end the war in Ukraine that was part territorial capitulation to the aggressor, part gangster extortion – offering Kyiv protection in exchange for mineral wealth. Vice-president JD Vance gave an ominously unhinged speech at the Munich security conference. He claimed that freedom is more imperilled by imaginary culture-war spectres haunting European democracies than it is by a Russian dictator whose tanks are churning up the sovereignty of a neighbouring state.

In case of any lingering doubt that the Trump regime has authoritarian ambitions, the president also asserted on social media last week that “he who saves his country does not violate any law”. It is a signal that judges, courts and constitution should all be subordinate to a leader whose personal preference is synonymous with the national interest. Coming from the man who fomented insurrection to overturn the 2020 election, Trump’s aphorism should be read as a hint that the spirit of Maga patriotism is vested in thugs and militias, not statutes.

This was the advertised programme. None of it should surprise the US’s allies. But it was easier to hope there might be momentum in the old order than to work out how to live in the new one. Now European leaders are scrambling to convene summits, scraping the sides of their depleted defence budgets, flexing atrophied military muscle in panicky gestures of continental solidarity.

There is no going back to Darcy’s world. The idea that human rights are universal and the principle that no one is above the law are losing ground to older axioms – big nations extract tribute from smaller ones; a strongman ruler makes the rules.

Pained by these existential challenges, it is hard not to reach for the anaesthetic balm of nostalgia, mythologising the late 90s and early 21st century as a golden age of liberal democratic primacy. In reality, that was a cosy bubble around one generation in one corner of the world: a historical fluke. To move on, we have to get through denial, anger and the other stages of grief to acceptance. We need to recognise that we live for the foreseeable future in a world without a friend in the White House, and that this points to a destiny for Britain much closer to Europe.

And we need politicians who will dare to say as much aloud. This, too, is something that occurred to me as I left the cinema last weekend. Maybe if we had leaders capable of expressing the magnitude of the crisis, and rising to the challenge, I wouldn’t have to look for messages of solace between the lines of Bridget Jones’s diary.

• Rafael Behr is a Guardian columnist