You can sometimes stand so close to something that you can’t really see it – like a man peering from a few inches away at the glass of a cathedral window.  So it is for Britain with Brexit.

Those who write about politics tend to get caught up in the day-to-day.  This is part of what we do: probe when Theresa May might move Article 50; peer at Labour’s death-wish as it re-elects Jeremy Corbyn; or turn, say, to today’s book serialisation about the referendum campaign.  We will return to all these; it’s our business to do so.  But today we look up from the detail and gaze towards the horizon.  Let’s stand back, at this start of the conference season for the country’s two biggest political parties, and marvel at the consequences of what we did on June 23.

Begin with the party that held its conference last week – the Liberal Democrats.  A Remain vote would have been claimed as a victory by David Cameron, and rightly.  It would have confirmed the Conservatives as a pro-EU party at Cabinet and Parliamentary level.  This would have left Tim Farron and his party with less space in which to proclaim a distinctive message.  The Brexit vote gives it a chance to do so, get noticed, appeal to the 48 per cent who voted Remain, and speed slightly its attempted crawl back towards power and prestige.

It is different for Labour.  Not so long ago, Labour was the more Eurosceptic of the two main parties.  Jacques Delors and Margaret Thatcher helped to change all that: for the best part of 30 years, Labour has been signed up to a pro-EU consensus, exemplified in Tony Blair’s three-times victorious New Labour project.  But Labour’s midlands and northern heartlands voted decisively for Leave in June.  The party must now come to terms, amidst its present chaos, with this seismic fact – a task made all the more difficult by its other and different base, London, plumping for Remain.

This leaves a golden opening for UKIP, or should do.  There is cultural resistance to the Tories in the urban north.  A new anti-immigration, protectionist, anti-globalisation party ought to have a chance of elbowing May’s party aside, and competing for Labour seats across a wide sweep of northern England.  But the party didn’t go for Paul Nuttall or Steven Woolfe.  Instead, it has plunged into faction-fighting ferocious even by its usual standard.  Even if it had not, however, a question would linger: if Britain is to leave the EU, what’s the point of UKIP?

That leaves the Conservatives: a party whose last leader, last Cabinet, present leader and present Cabinet – not to mention a majority of its MPs – backed Remain.  But the Party has got lucky, at least for the time being.  Its grassroots were for Brexit.  So were several of its best-known public figures: Boris Johnson, Michael Gove, Iain Duncan Smith.  Theresa May is consolidating her government behind June’s decision.  And with Labour MPs having gone one way and its members another, she has a chance to step in where UKIP is too divided to tread.

Thinking broadly about the future fortunes of our main political parties is bigger-scale than squinting at the narrow business of who did what to whom during the referendum campaign.  None the less, it is in its own way a failure of imagination.  Brexit will mean so much more than who wins in 2020.  At some point next year, Article 50 will be moved.  Two years after this happens, Britain will be out of the EU – unless all parties concerned agree to extend the process, which is unlikely.  Talks about trade and about terms will stretch on long after.  But out we will formally be.

This will represent a change in our self-image so vast that its implications are only now beginning to come home.  From Suez until last June, for the span of over half a century, the default setting among Britain’s political ascendancy was that the country’s vocation lay within a European combination: that we simply could not hack it as a self-governing country.  That conviction was probably at its strongest during the 1970s, when Britain indeed wasn’t hacking it, and when it duly entered the Common market.

We may not be able to do so now.  But the sum of June’s decision is that we are going to give it a go.  In particular, England decided to do so by more than the national margin overall: by 53 per cent to 47 per cent.  Outside London and much of the south-east commuter belt, many of the majorities were emphatic.  58 per cent went for Leave in the North-East; 59 per cent did so in the West Midlands; 58 per cent in Yorkshire and the Humber. Tory-voting rural England and the Labour-supporting north combined.  Wales too went for Leave.

It is very early days in which to assess the knock-on effects of the vote in Remain-supporting Scotland.  But even there, four in ten Scots voted Leave.  And there is some evidence that the prospect of independence outside the EU – with that oil revenue dwindling in value – is changing the way that Scots feel about leaving the Union.  Ruth Davidson’s poll ratings have overtaken Nicola Sturgeon’s.  So have Theresa May’s.  This doubtless won’t last, and more support for independence may return, but England’s decisiveness appears to have made an impression on the Scots.

We are set to become a self-governing country again.  This will have known and unknown consequences.  Among the known are that the Commons will recover some its political centrality, as powers flow back from Brussels to Westminster.  There will be an explosion in lobbying.  Among the unknown are whether Britain goes for a low tax, low regulation, free trade economy, which implies higher immigration rates than would otherwise be the case; or for a model with lower growth, less migration, protection and (by implication) postponed infrastructure decisions.

Brexit could also mean a concomitant withdrawal from international affairs – with fewer defence commitments, for example.  Or it could lead to the opposite: to Britain projecting its military force abroad more, as it seeks to prove that leaving the EU doesn’t mean leaving the wider world.  Either way, politics is going to be different.  “By voting leave, we can finally bring down the curtain on the Blair era,” John Hayes wrote on this site on the morning of the referendum itself.

He was right.  The May leadership could fail.  George Osborne and the Cameroons could make a comeback.  Labour could suddenly cast off Corbyn, and lurch back towards electoral reality.  But any or all of this would be surface movement; the depths would remain unstirred, untroubled.  On June 23rd, Britain made its biggest decision of the post-war era – far bigger than the original one to enter the Common Market, since that was not brought about by a referedendum decision.  We gaze at that cathedral window, but cannot yet begin to take in its size and scale.