Brexit: act in haste...

Sometimes cliches and hyperbole are inescapable. Britain’s decision to leave the European Union really is momentous; it really will reshape Europe’s political landscape; things really will never be quite the same again.

The implications of this entirely avoidable decision look uniformly bad, and not just for the UK itself – in the unlikely event that it continues to exist.

It’s worth pointing out that “Britain” didn’t really decide anything. In reality a bare majority, composed primarily of those outside of metropolitan, cosmopolitan London, and an increasingly independently minded Scotland, made the decision.

It seems a visceral, barely coherent dislike of elites, Southerners, the City and – most of all – those dreadful bureaucrats in Brussels played a bigger part in deciding the outcome of this vote than any objective debate about the future of Britain, much less Europe.

Add immigration, deindustrialisation, alienation, loss of identity, wrenching structural change and – yes – apparent incompetence at the heart of the European project, and it’s not hard to see why so many became so disenchanted.

But having vented their spleen, will Brexiteers come to rue the day? There are already signs that many are suffering an acute case of buyer’s remorse as they begin to actually realise what they have actually done.

It is not just the short- and long-term damage to the economy that is causing doubts. Even in the unlikely event the other EU members do not punish Britain for leaving by restricting access to the single market, Britain will still have to renegotiate a series of other trade deals from what Barack Obama famously warned would be “the back of the queue”. But the economic consequences of Brexit may prove to be the least of newly independent Britain’s worries.

Scottish First Minister Nicola Sturgeon has already indicated that she wants her country to remain in the EU, in line with the wishes of the majority of Scottish voters. Quite how this can happen without triggering the break up of Britain via a new independence referendum is unclear.

At the very least, it is one more layer of unnecessary uncertainty that has been triggered by outstandingly poor and/or opportunistic political leadership across the spectrum in England in particular.

British Prime Minister David Cameron is exhibit A in this context. His monumentally misjudged decision to offer an “in-out” referendum has brought about his own demise and may do the same for the UK.

It is entirely possible that Labour leader Jeremy Corbyn may join David Cameron on the political scrapheap, and perhaps he should. His lacklustre, half-hearted support for the Remain cause may well have led to its ultimate defeat.

Boris Johnson may end up having to try and repair the political and economic damage he has done so much to create with his unprincipled, self-serving about-turn on Europe. This is, after all, a man who claimed that it was better for Britain to remain in the EU as recently as 2015. Is it any surprise that so many are so cynical about the political process?

For all Johnson’s occasionally Churchillian rhetoric, he may not have much of a country to preside over. In the all-too-likely event that Scotland leaves, England will indeed be little, and of a vastly diminished global significance as a result. This matters for Europe almost as much as it does for England.

For all Britain’s failure to be a “good European citizen” at times, there’s no doubt it’s added to the EU’s importance and credibility. It’s the second-biggest economy and the most consequential strategic actor. It’s also been a useful counterbalance to the historically unpalatable prospect of German hegemony. Angela Merkel is not alone in recognising this importance and regretting its loss.

But even this is not the greatest danger created by Britain’s ill-considered decision. If the European project begins to unravel as a consequence of Brexit, it may mark the end of the most important and ambitious political project in history.

For all the EU’s undoubted problems, failures, inadequacies and hubris, it has definitively and unambiguously demonstrated that international co-operation is actually possible – even among countries that have spent centuries tearing each other apart.

So-called realists have always claimed that institutionalised co-operation across borders is unsustainable and that sovereign states ultimately cannot trust each other. Self-reliance rules. We are about to see an important empirical test of these propositions unfold before our eyes.

Europe’s appalling, blood-soaked historical record and propensity for self-destructive bouts of rabid nationalism remind us of just what is at stake.

The main reason such a resurgence of nationalism seemed unthinkable was because of the pacifying impact of the EU. Successful economic integration really does change the way people think about each other, especially when it’s produced by political institutions that are designed to achieve precisely that end. Even a bloated, expensive and inefficient bureaucracy seems a small price to pay for such a historically unprecedented achievement.

That this is happening when populist leaders and authoritarian politics are on the rise across the world should give us all pause for thought. Yet conservative commentators here and elsewhere offer entirely unconvincing, specious nostrums about regaining control and restoring sovereignty. Such platitudes ignore both the undoubted gains and inescapable necessity of interdependence in what is still a global environment.

The environment is but the most important and implacable reminder that none of the defining problems of the 20th century can be tackle without more co-operation rather than less.

The problems are difficult – some possibly irresolvable – but without mechanisms with which to tackle them, solutions are not even theoretically viable. A retreat into insularity, parochialism and nostalgia for the 19th century are plainly not the answers.

The likes of Putin, Trump and Xi may be the only beneficiaries of what will surely come to be seen as a disastrous turning point in the history of the West.

An earlier version of this article appeared in The Interpreter.