In Brexit, one of the three pre-eminent member states has revolted against the legitimacy of the European Union. That has caused crisis at home. What has it done to the Union? Not so much.

The project of integration in Europe started with the end of the Second World War. Some clear-headed thinkers, among them Winston Churchill, thought the time had come for Europe to reshape itself. Europe’s inclination, for centuries, had been to warfare. That culminated in the catastrophic World Wars of the twentieth century. The nineteenth century had been not much better: the Napoleonic wars, the Scandinavian wars, the Prussian wars against Austria, Denmark and France. And so on back through time.

Enough, these thinkers said. Europe is a danger to its peoples. It must be made safe.

A new constellation started to take shape with the European Coal and Steel Community in 1951, becoming the European Economic Community in 1957 and the European Union in 1993. The attempt, following the Napoleonic wars, to secure peace through balance of power had failed. The way now was to secure peace by binding the nations, with Germany and France at the core, together in mutual dependency. Today the Union embraces 28 countries, they will be 27 if Britain exits.

The Brexit process has revealed that  European integration has been extraordinarily successful. That has not always been easy to see, not least because of the reluctance, as many of us have been complaining, of the EU to reform.

But as Britain is trying to extricate itself, it has become visible how wide and deep the integration now is. Not only in commerce, trade, industry, finance, agriculture and fisheries, but equally in education, science, security, policing, culture, health care, residence, travel and much more, west-central Europe is now a genuine community. These countries have indeed become tied together in multiple bonds of dependency, as envisaged when the project of integration was launched. It has happened, it is a fact, it works.

The strength of integration is visible in the impossibility in Britain of finding a workable way out. It is visible in the need to re-write the bulk of existing legislation. It is visible in the multiples costs that will incur from trying to break from the bonds that have been tied during nearly seventy years. Of course those bonds are in some way a burden: that’s the point, the burden of mutual commitment.

Brexit will come at a cost to the Union as well as to Britain, but less to the Union. It has been challenged, and it has withstood challenge. If anything, Brexit has shown how much practical, day-to-day and down-to-earth reality has materialised from the visionaries’ lofty idea of integration. If this is a battle, the EU has won.