Whatever happens now, nothing will be the same again. So fixated have we all been – understandably – by the prospective outcome of the Brexit process that we have barely had time to inspect the damage it has wrought. And that damage is, quite frankly, immense.

For a start, the farcical saga stretching from the 2016 referendum itself to today has diminished Britain in the eyes of the world generally and the European Union specifically. When Donald Tusk, the European Council president, said in February that there was “a special place in hell” reserved for “those who promoted Brexit without even a sketch of a plan”, he spoke for a continent baffled and exasperated by the blundering self-sabotage of a supposedly great nation.

What the rest of the world cannot fathom is why the UK has, in effect, declared war on itself. I think it was the historian Richard Davenport-Hines who first made the observation that “Brexit is Britain’s Vietnam” – and he was right, with the obvious difference that we did not have to send troops thousand of miles from home in order to descend into domestic divisiveness and vituperative argument.

The central irony of Britain’s planned departure from the EU is that it has compounded all the problems it was intended to solve. The great emancipation from Brussels that was meant to set the nation on course for unprecedented prosperity has brought only economic uncertainty and disinvestment.

If anything, Theresa May’s obsession with immigration control has deepened: but she and her ministers do not explain how they will fill the jobs that were previously taken by EU migrants – especially in the NHS, social care and service sector. Nativist sentiment has been given greater priority than economic rationality – madness priority in a world that depends more than ever upon the ready flow of labour.

And far from assuaging resentment of the political elite or reassuring those who feel “left behind” by the forces of globalisation, the twists and turns of Brexit have entrenched the anger that drove the original vote to leave three years ago. Rarely have government and parliament seemed so useless or out of touch than in the months since Article 50 was triggered: at odds with one another, muddled by strategy, stuck in a quagmire of indecision. Take back control? You’re having a laugh.

But this resentment, of course, was an inevitable by-product of the campaign that drove Leave to victory. The greatest failing of populism is that it promises simple solutions to complex problems: and few problems are as complex and technically challenging as the extraction of a nation from a multitiered supranational alliance of which it has been a member for more than four decades. It is easy to plaster lies on the side of a bus. Not so straightforward to pass the 900 statutory instruments required to ease Britain out of the EU legal framework.

As anger and impatience have become the default mood of the electorate, so we have witnessed a sorry coarsening of public discourse. British political rhetoric has always been vigorous, mischievous, sometimes scabrous. But a new ugliness has entered the soul of the polity.

Perhaps most toxically, this unhappy saga has (again, like Vietnam) turned generation against generation

It has become routine to speak of “traitors”, “enemies of the people” and “saboteurs” and to slander those who dare to question the wisdom of Brexit as foes of democracy. In little more than three years, the civility that is the essence of a parliamentary system has drained from Westminster. Where do we go to get it back?

Indeed, could we? Public life has now been so thoroughly colonised by social media that it is harder than ever to imagine a time when true statesmanship might be given the chance to cut through.

It is no accident that Donald Trump uses Twitter as his chosen message delivery system: he understands the spirit of the age, in all its brutality. He also grasps that a democracy stripped of trust is uniquely vulnerable to agitation, emotional hyperbole and clandestine cyber manipulation.

This divisiveness has been matched by disaggregation. Both main parties have struggled – and not always managed – to maintain even a semblance of unity in these testing times. The referendum that was called to hold together the Conservative Party has merely sharpened its factionalism and apparently insoluble disagreements.

Meanwhile, Jeremy Corbyn’s fence-sitting has appalled his overwhelmingly pro-Remain parliamentary party and members and radically increased the chances that a group of disillusioned centre-left MPs will indeed break away from Labour in the near future.

Perhaps most toxically, this unhappy saga has (again, like Vietnam) turned generation against generation. The People’s Vote campaign stumbled in its earliest incarnation, too closely resembling the liberal elite trying to get its job back. But it became -altogether more impressive when it morphed into a grassroots uprising of the young against their foolish elders.

In the cacophony of Brexit, few voices have been more eloquent than those of Femi Oluwole, the 28-year-old cofounder of Our Future Our Choice, or Will Dry, co-president of the same group. Their precocious leadership offers grounds for optimism about Britain’s long-term future – but not the readiness of their generation to forgive the follies of mine.

The most ridiculous argument I have heard in the past three years is that, with Brexit out of the way, business as usual can be resumed and other, no less pressing, questions of public policy addressed by our politicians. But this is to misunderstand completely what has happened in the past three years and its enduring impact. We have barely begun to grasp the full extent of what has already happened and what may lie ahead. If you think it’ll all soon be over, then – seriously – think again. It gives me no pleasure to say that this is just the start.

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