There is a real danger that we spend the next decade refighting last week’s referendum. If Scotland’s recent experience is anything to go by – where there are now two entrenched camps of yes and no voters in the aftermath of the 2014 independence referendum – then the battle lines drawn in a bitterly fought and polarising EU referendum will define our politics for years to come.

Already we see the divide between remain and leave becoming the centrepiece of the narrative about the British economy. Remainers feel they have to be pessimists to prove that Brexit cannot be managed without catastrophe, while leavers present themselves as the optimists, claiming the economic risks are exaggerated.

A referendum that started off as an attempt to paper over divisions in the Tory party has now divided the whole country to its very core, and left us more isolated from our international partners than at any time since the humiliation of Suez.

A diverse country such as ours cannot afford years of the leave campaign’s inward-looking, anti-immigration rhetoric. But nor can we make progress through the remain camp’s tactic of brushing aside the country’s key concerns.

Because the remain campaign decided to make the negative argument – that leaving was a risk – and not to articulate any positive, principled case, the two great Eurosceptic myths about the betrayal of Britain remain unaddressed. At no point did the Tory leadership ever challenge the leave campaign’s lie that Britain was about to be subsumed into a federal superstate, and thus leave stole the mantle of patriotism, castigating pro-Europeans for selling Britain out to Brussels.

And by focusing entirely on proving we would be financially worse off, the Tory leadership never contested the illusion at the heart of the slogan “Take back control” – that in an increasingly interdependent world nations can avoid combining together to tackle pollution, financial instability, protectionism and inequality. Only the collective clout of Europe, for example, can bring tax havens into line.

If we have no option but to balance the national autonomy we desire with the international cooperation we need, then we must make the positive case for Europe, and address rather than sidestep the issues of national identity and migration. Yet every time migration threatened to become a headline issue, the remain campaign escalated the rhetoric about post-EU doom, and so the extravagant leave claims about migration went unanswered.

The elephant in the room is globalisation – the speed, scope and scale of the seismic shifts in our global economy. And the most obvious manifestation of the world we have lost is the hollowing out of our industrial towns as a result of the collapse of manufacturing in the face of Asian competition. These towns are home to a disproportionate share of the semi-skilled workers who feel on the wrong side of globalisation and who opted to vote leave. Unable to see how globalisation can be tamed in their interests, they have, not surprisingly, become recruits to an anti-globalisation movement whose lightning rod is migration. To “take back control” seems the only way to shelter, protect or insulate yourself against global change.

Clearly Britain cries out for someone – or something – to heal the wounds inflicted during this campaign. This is not a question that is academic, or can wait. The Scottish government’s rush to break-away raises an existential question, and already the United Kingdom looks united in name only. If Lord North went down in history for losing one union – with America – David Cameron could go down in history for losing two unions – with Europe and Scotland.

But there is a way forward. First, we need a national conversation, and a national commission, on making globalisation work for Britain. If we cannot show how we can make globalisation fair and inclusive, then anti-globalisation movements will continue to mushroom and our politics will revolve around nationality, race or simply identity. Some say the modern dividing line in politics is between those who are for an open or closed world. But that categorisation seems to me to be the refuge of those who want to drain any ideology out of the system and who do not wish to face up to the massive inequalities that are globalisation’s achilles heel. The real dividing lines are between those who are for a managed and well-led globalisation – which tackles its injustices – and those who oppose intervention either because they support a global free-for-all or are simply anti-globalisation.

The commission I propose should examine the most controversial issue arising from the free movement of capital, labour, goods and services – namely migration. I would recruit people who are well-versed in these concerns from all over the world; and appoint a minister to coordinate the work.

Second, we must quickly end uncertainty over Britain’s future relationships with Europe with the same kind of an in-depth scrutiny of all the possibilities – the Norwegian, Swiss, Canadian and World Trade Organisation model – that we did when considering whether to join the euro. We should look seriously at how the Norway or European Economic Area option could keep us in the single market, and we should combine this with a close examination of how the protocols we would sign in joining, and its “safeguard measures”, can be used to manage migration. Once the results are known, we should leave ourselves open to listening to any alternative proposals that come from the European Union.

Third, the Scottish government wants to investigate only how Scotland can be part of the European single market. But it is more reasonable to start with an assessment of how Scotland can retain the benefits of being part of both Europe and Britain. We should do so not just because it is in our economic interest – £46bn of Scotland’s annual trade and 1 million jobs are linked with England, while £12bn in trade and 250,000 jobs are linked with mainland Europe – but also because we cannot speak meaningfully and convincingly of interdependence and solidarity – or of our desire for cooperation and sharing – with our neighbours across the North Sea, without a sense of how we can work with our nearest neighbours who share the same small island.

Of course, the country will look first to the Tory party to see whether it can unite Britain. But the party that can best tame globalisation is the Labour party. Today’s vote among the parliamentary Labour party focused on our electability. But there is a more profound challenge than whether we are a party of protest or a party of power. We have to decide that we cannot simply be an anti-globalisation party that exploits grievances but offers no answers. Only then can a reformed Labour party show that we can make a currently leaderless globalisation work for the people of Britain.