One of Brexit’s more pernicious aspects, even before you get to its actual flaws, is its tendency to suck all available oxygen unto itself, to drain resources that might otherwise have gone elsewhere. Before the referendum, civil servants warned that such a task – untangling 40 years of legal agreements, ripping out a delicate web of connections that had become embedded – would consume all their energies. Naturally, their warnings were dismissed as Project Fear. But even the head of Vote Leave, Dominic Cummings, before he took on the form of Benedict Cumberbatch, conceded via Twitter that leaving the European Union would present the British state with the “hardest job since beating Nazis”.

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Just think of what else we could have done with all that time and money, including the £4bn we’re spending to guard against the entirely avoidable and self-inflicted calamity of a no-deal crash-out from the EU. The effort we could have made for jobs or housing, or to repair the damage inflicted by austerity; the work that could have been done to improve life for those left behind by three decades of change, globalisation and automation. But Whitehall didn’t have the bandwidth. Governments might be able to walk and chew gum at the same time, but walking while shooting yourself in both feet – that, it turns out, is impossible.

It’s not just the machinery of state that has seized up since June 2016, all but paralysed by Brexit. It’s affected what you might call the attention economy too: both the news media and its consumers, those who shape the collective conversation and those who take part in it. So enveloped are we in Brexit that we hardly have the space to contemplate anything else. Our gaze is turned inward, and we can barely see what’s going on around us.

If news bulletins, front pages and social media feeds were your guide, you’d think climate change had gone away, quietly resolved while we were obsessing over the Northern Ireland backstop. Not so. It barely made a ripple, but last week came word that the oceans are warming at a rate some 40% faster than previously understood. Remember, it’s the seas that absorb most of the extra heat going into the climate system, and the dangers posed by a rise in ocean temperature are clear and present, whether it’s fuelling ever more extreme storms and hurricanes or increasing sea levels, thereby flooding low-lying areas and rendering potentially hundreds of millions homeless. It’s just one more sign, along with melting ice-sheets or the drying up of the Rhine, Europe’s most critical waterway – where low water is rendering whole stretches impassable – that while the government tears itself apart trying to fulfil a nostalgic fantasy of taking back control, global temperatures are getting relentlessly out of control.

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Perhaps it’s harsh to blame Brexit for our apathy about climate change, which long predates the 2016 referendum. But even those subjects that we used to discuss barely get a look-in now. The war in Syria rages on. This week, as MPs were debating their confidence in Theresa May, the UN reported that at least 15 infants, including eight babies, had died for lack of medical care and from extreme cold. Most of their families had fled the fighting to seek refuge on the Jordanian border. It’s a reminder that the world has not stopped turning just because we’ve stopped looking.

More pertinent for Britons, perhaps, given our government’s still warm relations with the country, is that Saudi Arabia’s dirty war in Yemen goes on, causing what the UN has repeatedly called the world’s worst humanitarian disaster. It is a war so dirty that even the perpetrators are victims: the Saudis are recruiting young survivors of the horrors of Darfur to serve as child soldiers on the front line.

In the 1980s, pictures of starving children in Ethiopia prompted global outrage and determination to act. Now, footage from Yemen of emaciated babies and wizened toddlers, and a toll of 85,000 children dead through hunger, induces no more than a shrug. And yet, the famine in Yemen should offend us morally at least as much as the suffering of three decades ago, for this catastrophe is entirely manmade, and therefore avoidable.

Perhaps it’s giving ourselves too much credit, but I’d like to think that, were we not so distracted by the customs union and Norway plus, we would at least have registered that China is currently holding an estimated 1 million Uighur Muslims in the Xinjiang region in what seem to be Mao-style “re-education camps”. Forced to listen to hours of Communist party propaganda aimed at their “rehabilitation and redemption”, inmates are held in squalid conditions and subject to brutal interrogations. There are reports of prisoners taking what, in their despair, they conclude is the only way out: suicide. One former captive describes being held still in a “metal device” that kept him entirely rigid. That rather puts our debates about “free movement” into perspective, doesn’t it?

The Chinese authorities call these places, which satellite photographs reveal have dramatically expanded, “vocational training centres”. But they are behind barbed wire and high perimeter walls. The authorities say they inoculate “trainees” against the lure of terrorism. The truth is they represent state persecution of a reviled religious minority. The historical resonances are obvious, and should have provoked fierce condemnation from our leaders. But they, and we, are all too busy.

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Even those stories that not long ago commanded our attention now struggle to be noticed. Last year, Israel’s use of live ammunition against protesters at the Gaza frontier rightly made big news, as did the presence of antisemitism within Labour’s ranks. You might imagine both issues had faded away, given how rarely they’re now discussed. But the Gaza protests continue and the anguish of daily life there has not receded: witness, by way of an exception, Mishal Husain’s BBC report from a hospital struggling to function.

Meanwhile, every day brings fresh evidence that within Labour’s ranks there remain some deeply suspect attitudes toward Jews: note the Labour councillor in Fife who reckoned concerns about anti-Jewish racism were all part of a Mossad-orchestrated plot – in other words, a Jewish conspiracy. She was briefly suspended but is now safely back in the Labour fold.

Or you could look to the United States, where the former Trump campaign chairman, Paul Manafort, has admitted sharing polling data with the Russians – as slam-dunk a proof of collusion as you could wish for. So conclusive is it that Trump’s own lawyer, the once credible Rudy Giuliani, has reversed his previous line of defence: now he all but admits there was collusion, but says Trump himself was not involved. It’s all happening out there, but our minds are elsewhere. It means we don’t even have to wait to leave the European Union to see that the notion that Brexit would forge a global Britain, eager to head “out and into the world” was bogus. We can already see that it’s doing the opposite to us, turning our gaze ever more inward, shrinking our horizons – and ourselves.

• Jonathan Freedland is a Guardian columnist