There's no going back – May has burned the boats of a divided nation | Martin Kettle

Like Aeneas fleeing from Troy on the shore of Italy, or Cortés on the coast of Mexico, it was a moment for the burning of the boats. On Wednesday Theresa May burned hers. But they were our boats too that she burned, Britain’s boats, boats in which, for half a century, postwar Britain has tried to reconcile its history and its future in Europe – and failed. For good or ill on both sides of the channel, Britain will not be returning to the European Union.

It doesn’t get more serious than that for this country. Yet it ended, as it began, with more of a whimper than a bang. As 1973 dawned, the Guardian reported that Britain had embarked on its membership of Europe without fireworks. “It was difficult to tell that anything of importance had occurred,” records the paper’s front page, “and a date which will be entered in the history books as long as histories of Britain are written, was taken by most people as a matter of course.”

Forty-four years later, as Britain began packing its bags to leave, there was perhaps more excitement among the political and journalistic classes. The most predictable front page of the year was the Daily Mail’s single word headline on Wednesday: “Freedom!” But the Guardian surely got the wider national mood more accurately: “Britain steps into the unknown.”

Politically, it was momentous. A version of the same resistance to continental encroachment that fired Henry VIII’s break with Rome 500 years ago has triumphed again. Out in the country, much as in 1973 or even 1534, people got on with life as usual. If they were delighted or anxious, they mostly didn’t show it. There were no crowds in the streets this time and no celebrations or protests to speak of either. People kept their feelings quiet. Trains ran. The stock market was unmoved. Rain came in from the west. As usual, a million people went to the doctor.

Nevertheless it was the most important and the most carefully choreographed day of Theresa May’s prime ministership, and she did her best to rise to the occasion. Her speech to the Commons was consensual and without a single triumphalist note. Only Sir Bill Cash on the leave side and the SNP’s Angus Robertson on remain’s managed to raise the emotional temperature in the chamber.

None of it affected the prime minister, however. In her letter to Donald Tusk there was a not so veiled threat to take UK defence and security commitments to Europe off the table if the EU forces too hard a bargain on single market access. If nothing else, that was proof of how badly May wants a deal in her own prescribed timeframe of two years. What a gambler the vicar’s daughter has turned out to be.

But in the Commons there was no Thatcher-style warrior talk about days of destiny or independence. Instead May’s chosen tone was soothing and respectful, both to the EU and to British voters who support it. Her audience was in the capitals of Europe, not the Commons chamber. She sought a “deep and special” partnership with Europe. Her peroration contained the word “together” no fewer than six times. At times it was hard to realise that Britain is walking away, so often did May praise the EU, wish it well and invoke its values.

There was very practical domestic political reason for this emollience too. Despite her wish for the country to come together on the issue, Britain is still deeply divided over Europe. Nine months ago, 17.4 million Britons voted to leave, while 16.1 million voted to remain. A YouGov opinion poll this week suggested that views haven’t changed much. Neither side of the arguments regrets the stance it took last year. Remainers are beginning to accept that there’s no way back. But May, unlike the newspapers that urge her forward and constantly try to make her into a second Thatcher, does not choose to grind the faces of the 48% who voted remain into the dust.

Leaving the EU is “this generation’s chance to shape a brighter future for our country”, said May. It offers “a chance to step back and ask ourselves what kind of country we want to be”.

That sounds very benign and consensual, as it is supposed to, until you realise that “this generation” is in fact not a fixed thing. Britain is divided not united across its generations, including Europe. In the YouGov poll this week, 65% of young people aged 18-24 say it was wrong to vote leave, against just 12% who think it was right. At the other end of the age spectrum, the over-65s say the opposite, with 62% saying it was right to leave and 31% saying it was wrong.

So this isn’t really “this generation’s chance”. In fact it’s the older generation’s chance to break a relationship with Europe that the younger generation wants to keep. Looking backwards has defeated looking forwards – or has until the leave voters die out and, perhaps, leave the new majority more pro-European. At the end of her speech May invoked a misty-eyed vision of “a stronger, fairer, better Britain – a Britain our children and grandchildren are proud to call home”. The problem, though, is that leaving the EU isn’t going to produce that kind of Britain. As the historian Anthony Barnett put it: “Brexit is government of the old, by the old, for the old.”

As she signed the letter triggering Britain’s exit from the EU on Tuesday, May had posed beneath a portrait of Sir Robert Walpole, often described as Britain’s first prime minister. Eurosceptics think highly of Walpole because he prioritised getting extremely rich over European entanglements. In one of his most quoted remarks, Walpole boasted to Queen Caroline in 1734 that “there are fifty thousand men slain this year in Europe, and not one Englishman”.

What the Eurosceptics always forget, though, is that Walpole served a king, George II, who was ruler not just of Britain but of Hanover and was therefore entangled in Europe whether he wanted to be or not. It was always thus for this island. The Guardian’s striking front page showed the British jigsaw piece removed from the European whole. But real countries do not move. They stay where they are. Britain will be part of Europe, one way or another, until the end of the world.