Few years will live as long in the memory as 2016. Historians will ponder the meaning and consequences of the past 12 months for decades to come. In the future, 180-odd years from now, some Zhou Enlai will remark that ‘it is too soon to say’ when asked about the significance of Brexit.

The referendum result shocked Westminster. Michael Gove was so sure it would be Remain that he had retreated to bed on the evening of 23 June and only found out Leave had won when one of his aides telephoned in the early hours of the morning. Theresa May admits in her interview with us on p. 26 that she was ‘surprised’ by the result and had been expecting a Remain vote, based on both the polls and the mood in her own constituency.

But while Leave’s win reverberated through Westminster on 24 June, the fact that Britain voted to leave the European political project is perhaps not all that surprising. After all, we joined the then European Economic Community because, in Dean Acheson’s hackneyed phrase, we had lost an empire and not yet found a role. Unlike nearly all the other member states, our EU membership was not a matter of national pride.

That Britain would depart at some point became highly likely in 1992, when John Major negotiated a UK opt-out from the single currency. Not being involved in the central political project of the European Union made Britain a semi-detached member. It became hard to argue that we were ‘leading in Europe’. As pro–Europeans such as Roy Jenkins and Peter Mandelson had always recognised, if Britain was to stay in for the long term, it had to join in full. George Osborne used to say, privately, that the renegotiation must show that there was a third way between leaving the EU and joining the euro. Ultimately, the deal David Cameron secured failed to do that.

Negotiating the terms of Britain’s departure will be complex and it will dominate British politics between now and the next general election; it is hard to imagine that the government will be able to think about much else for the next few years. Already, at the centre, there is constant chatter about sector-by-sector deals and whether a transitional arrangement is needed.

The UK’s negotiating position is far from settled. Inside government, debate still rages about whether we should aim to remain in the customs union for certain sectors or whether we should simply try to negotiate enhanced customs procedures as part of a free-trade deal. After all, more trade occurs between the US and Canada than over any other international border and the two countries are not in a customs union with each other. Staying in the European customs union would undoubtedly be convenient in the short term — but it would limit Britain’s ability to make trade agreements with other countries to an unacceptable degree.

The scale of the task of leaving the EU will become clear next year when Parliament moves to incorporate EU law into UK law. Cabinet ministers say, only half joking, that they want to get their legislation completed now, because once the Brexit process has started there’ll be little time for anything else. The exercise will show just how much control Parliament had ceded to the EU.

There is a danger, though, that the sheer complexity of leaving blinds the government, Parliament and the country to the bigger question: what kind of country does Britain want to be after Brexit? Inside the Vote Leave campaign there were different answers to this question. The two leading Tory voices — Boris Johnson and Michael Gove — are among the most ‘open’ politicians in Britain. They are economic liberals who believe in the benefits of free trade. They objected to the European Union on sovereignty grounds but also because it was too dirigiste and restricted Britain’s engagement with the world. Still, one cannot escape the fact that many of those who voted for Brexit did so because they wanted more protection from foreign competition — leading to less trade and immigration. Yet if Britain is to make a success of Brexit it will be as an agile, open, trading nation.

At times, the government’s response to the Brexit vote seems to rest on an attempt to fuse together these two strains of the Leave vote. Theresa May talks about Britain being a global leader in free trade and emphasises how she wants the UK to strike trade deals around the world. But the government also comes out with cack-handed ideas such as getting firms to detail the percentage of foreigners in their workforce.

Immigration is the vexed issue here. It is thought that many of those who voted for Brexit did so to cut immigration, and if it doesn’t now fall significantly there will be a turn against mainstream politics. This may well be true of some Leave supporters. But there is a reason why Vote Leave’s slogan was ‘take back control’. As a member of the EU, by definition, the government couldn’t control freedom of movement and automatically had to accept unskilled immigrants simply because they came from an EU country. Whatever your views on immigration, this was a dramatic loss of sovereignty.

However, once Britain leaves the EU, a new immigration policy can be fashioned. This will involve some unskilled immigration — Whitehall has identified social care, construction and hospitality as sectors where the UK will still need low-skilled workers from the EU after Brexit — but the policy will be based around what the British economy needs. The fact that the UK government is in control will, I suspect, make it far more palatable to the public.

National control is the crucial point of Brexit. Decisions are much easier to sell to voters if it is clear that they have been made in the national interest and if voters also know that, by exercising their democratic rights, they can remove the decision-makers from office if they disagree with what has been done on their behalf. This control will help to curb the feelings of impotence that fuel the rage against globalisation. Brexit should be guarantor of Britain’s inherent liberalism in the decades ahead.