It’s not just the UK that will be dramatically altered by Brexit – the EU will feel it too

Will it grow into a streamlined economic and diplomatic tour de force, or will it descend into bickering about its purpose? It’s anyone’s guess at this stage, but huge change is afoot regardless

If you were to single out one mistake (of so many) that the UK government has made in its Brexit negotiations with Brussels it would be the apparent assumption that one day the EU27 would crack.

All we had to do was wait: then the old colonial practice of divide and rule would come into its own and our imperial carriage would ride right through.

That calculation was wrong. As we enter what may or may not be the last two months of this agonising process, not only have the EU27 still not cracked, they are ridiculing the disarray they observe on the other side of the Channel.

When the EU parliament met in Brussels on Wednesday to consider its response to the Commons votes the previous day, the old Belgian war horse Guy Verhofstadt was not alone in challenging London’s boast that its position was now clear.

Reeling off the narrow margins of the amendment votes, he asked how these “teeny tiny majorities” possibly conveyed unity. “Every day,” he charged, “you are changing your opinion.” Plumbing one of the constant undercurrents of Brussels debates, an MEP from the German Linke (Left) laid it on the line: “We can’t act as though the British Empire was more important than the EU.”

So far, then, so good for EU solidarity. The 27 have stood behind the Brussels negotiating position. Time and again they have circled their wagons to protect Ireland, even as London has sniped from the sidelines.

Neither the European Commission nor the EU parliament had any difficulty approving the “deal” over which Theresa May has lost ministers and negotiators and is now finding nigh-impossible to get through parliament. If there is any tension between Michel Barnier, Donald Tusk and Jean-Claude Juncker, they are not showing it. They are still standing as one.

This is not to say, however, that this unity will last. The UK’s miscalculation was to bank on the EU’s internal tensions weakening the stance of Brussels on Brexit. That has not happened, because Brexit has been treated by the EU from the outset as an existential question.

Rather than encouraging others to follow, as many Continental Europhiles had feared, the EU referendum result had the opposite effect; centrifugal tendencies were suspended in the name of survival.

But what happens if – most likely when – Brexit comes to pass? It has long been part of the Brexiteers’ argument (as represented by Boris Johnson and others) that the EU has as much, if not more, to lose from a no-deal outcome, so all the UK needs to do is hang tough, and Brussels will blink.

This remains to be proved. That the UK’s departure will have an effect, and maybe a destabilising effect, on the EU, however, is acknowledged by many politicians and observers inside the EU. The question is how disruptive will it turn out to be.

Earlier this week I was in Rome for a conference organised by the Italian Institute of International Affairs at the Italian Foreign Ministry, where precisely this question became a recurrent theme. Once delegates had registered their surprise and bemusement at the goings-on in Westminster, they turned to the future of the EU without the UK.

And while not necessarily pessimistic – there are plenty of Europeans who have long hailed the UK’s departure as potentially removing a longstanding obstacle to greater cohesion – everyone acknowledged that Brexit is going to make quite a difference. It will change both the alignment of the EU and the balance of power within it – but how?

First, it is recognised that the departure of an EU member is not only without precedent, but something that goes against the whole spirit of the European project, which has been only about expansion and enlargement hitherto.

This may be one reason why the EU has maintained such a united stance during the negotiations, and why it was taken for granted that leaving could not be seen as conferring the same – or better – benefits than remaining, as this would undermine the EU’s whole reason for existing.

But, second, could the solidarity that the EU27 found in the face of Brexit foster a new cohesion – and, if it does, will that be positive or negative? Positive in giving the EU more economic and political clout internationally, but negative in permitting degrees of national difference within the EU?

During its time in the EU, the UK – by virtue of its size, its economic clout and its history – was accorded a host of privileges in terms of special arrangements and opt-outs. Yet, despite these, the UK decided to leave. Did its special status serve to delay its inevitable departure – or should it rather be seen as (in the words of one delegate) a “harbinger of disintegration”? Should the EU in future be so permissive of difference?

This is a question dear to Italian hearts. The official title of the Rome conference referred to “shaping the EU’s future through differentiated integration” – a concept that has been around for so long that some of the senior Italian delegates recalled writing their student theses on it several decades ago.

Akin to unity in diversity, it can perhaps be explained as the leeway that Italy (and others) want and need to be full members of the EU, while not being dictated to by France and Germany. Will the effect of the UK’s departure be to foster greater uniformity in the name of cohesion? Will the idea of differentiation now be tainted?

One example of greater cohesion is the new impetus Brexit has given to the formation of an EU military and defence structure (otherwise known, not quite accurately, as a European army). This project took on new life almost as soon as the UK voted to leave, as it was something London had adamantly opposed. It also threatens to be divisive, as eastern and central European countries prefer to rely on Nato. Without the UK there to support them, however, their voice may count for less.

And not only on security issues. With the UK – a big and rich country – gone, the balance of those EU countries inside and outside the eurozone changes dramatically. Will those still outside the eurozone – Poland, Denmark and Sweden – come under new pressure to join?

If, as the French president is arguing – and slightly more reluctantly Germany – a new structure for managing the eurozone is needed, including a central budget and even coordinated taxation, what then happens to those who do not want, or do not qualify, to join?

Will there then be a two-speed or even a multi-speed Europe, or a Europe à la carte? And would this herald the advance of the EU, or its decline? Certainly, any development along those lines would be anathema to the “new” Europeans who are acutely sensitive about being treated as “second-class” citizens.

Poland and Hungary already feel they are being treated unfairly – in part because of the governments they have elected – and would fight tooth and nail against any formal distinction between inner and outer tiers, a “core” and a “periphery”.

The irony, of course, is that a two-tier EU might have been more congenial to the UK than the European Union it found itself a part of, and such a union might, had it been formalised before, have rendered the whole Brexit process unnecessary.

But it is too late for that now. The UK will be changed by its departure; indeed, it is already changing. Less noticed (from here at least) is that the EU will be changed, too. Will it be strengthened or weakened?

Will it grow into a streamlined economic and diplomatic tour de force, or will it descend into bickering about its purpose? What sort of a neighbour will it be? With Brexit complete, our roles could in one sense be reversed, as we start to watch their drama from our side of the Channel.