David Cameron and his wife Samantha walk back into 10 Downing Street after he spoke to the press following Britain's vote to leave the European Union on 24 June 2016. Photo by Getty Images.

David Cameron and his wife Samantha walk back into 10 Downing Street after he spoke to the press following Britain's vote to leave the European Union on 24 June 2016. Photo by Getty Images.

When pushed during this EU referendum campaign for a prediction on the result, I tended to conclude, however cautiously, that Remain would win a tight race. But I always ended with the warning that we are living in a ’Trumpy world’. Like most people, including most of those campaigning for the UK to leave the EU, my sense of the likely result turned out to be wrong and my warning correct.

An unexpected majority of British voters have overthrown not just Britain’s relationship with its European neighbours but the established political order in the UK, and, potentially, Europe. This result was as unexpected as Donald Trump taking the Republican presidential nomination. In the US, however, voters have yet to decide whether to entrust Trump with the keys to the White House. In the UK, those who promised to the British people that leaving the EU would let them ‘take back control’ over their lives are now expected to deliver on that promise.

This will not be easy. Blaming the EU for all of Britain’s ills has been pure displacement activity. Contrary to some of the rhetoric, the EU has not hogtied the UK in regulation and has not drained funds from the Exchequer. Being a member of the EU is not the reason that Britain has failed to live up to its self-image as a ‘proud trading nation’. Britain’s ills − and there are many, as this vote has revealed − are self-inflicted.

Nor has EU membership made Britain less secure domestically or influential internationally. Being in the EU has generally complemented the UK’s military and diplomatic objectives, whether in dealing with Russia, Iran or ISIS. Britain in the EU was not in ‘managed decline’, as one pro-Leave politician described it again this morning – in fact, as those same politicians often pointed out, the UK is prospering as the world’s fifth-largest economy and has remained one of its most powerful nations.

This means that the triumphant Brexiteers now need to fold the popular expectations they have raised within the envelope of reality. In the near term, they may have some breathing space. Financial markets will hopefully stabilize once they have digested this shock to their expectations. And EU governments are unlikely to want to compound the risks to their own political and economic situations by pushing for a rapid Brexit. Britain’s market and businesses remain fully integrated into the EU for the time being.

But fairly quickly, Britain’s weaknesses outside the EU will be scrutinized more carefully than they were when it was inside, including its continuing high annual budget deficit and growing debt, as well as its persistently high current account deficit. Fixing these weaknesses will require structural reforms that will take time and may end up punishing the very voters who believed that voting for Brexit would somehow change their lot in life for the better.

In order to prevent a downward economic spiral and popular disappointment, the UK will need to negotiate an exit from the EU that preserves for its economy as favourable terms of access to the EU single market as possible. The EU market will remain by far the UK's most important, yet these terms will not be as favourable as they are today. Immediately thereafter, the government will need to re-negotiate bilateral trade deals with its non-EU trading partners, from the weaker position of being the one demanding the deal. And each of those deals will need to be designed not to conflict with its new trade agreement with the EU.

However this plays out, the UK government will need to devote enormous government and diplomatic attention to the EU for the indefinite future – ironically, far more than it did when it was a member.

The terms of the UK−EU agreement will not only be vital for British jobs and businesses. They will also be central to the future of the United Kingdom. A rapid move to a new vote on Scottish independence is unlikely. But, once Scotland gauges the sort of deal Britain has struck with the EU, it can go back to the people to vote for an independent Scotland to remain in the EU. Even more complex will be the long-term arrangements for the border between Northern Ireland and the Republic of Ireland, given that this will become the land border for those travelling into the UK from the EU, including potential immigrants.

I wrote in May that leaving the EU would carry more risks for Britain than opportunities. I remain of this view. The British politicians who will lead the UK out of the EU need to guard, therefore, against allowing a yawning gap to emerge between their political rhetoric and the realities facing Britain outside the EU. David Cameron made this mistake in the lead-up to the EU referendum, when, as I noted at the time, his deal with other EU members to limit in-work benefits available to EU immigrants made it impossible to deliver on his general election pledge one year earlier to reduce net immigration to the tens of thousands.

Boris Johnson and Nigel Farage now claim June 23 was Britain’s Independence Day. In the 1996 movie of the same name, victory for humanity followed the destruction of much of the planet by an invading alien force. Contrary to the movie script, leaders of the Leave campaign have the duty to ensure that calamity does not follow their own decision to advocate a future for Britain outside the EU. And we will each need to play our part to help achieve a positive outcome from this decision for Britain and its partners.

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