For a passionate European, there is now a strong case for Britain to leave the European Union (EU). By passionate European, I mean someone who sees the EU, for all its absurdities, as the noblest of post-war political projects — one that must and will lead to a federation, probably of a loose, Swiss kind, with a directly or indirectly elected president and a European Parliament with teeth. Someone who will love Britain to support this, but realises it never will. Why want a federal Europe? To create a powerful political centre, based on the supranational rule of law supervised by an independent court of justice, which can be the ultimate focus of loyalty for nations that have lived under dictatorship and whose horrifying memories cannot be erased.

The euro crisis is a fillip to this process, despite the error of including southern “Club Med” nations from the outset. Even if they leave the single currency, they will not stand aside from a banking union, not to mention other federalising moves. The process is far from over. The fundamental mission of the EU — to inspire and attract the loyalty of democracies, whether or not they join as full members — will continue on account of its supranational law and the cohesion this brings.

No post-war British prime minister has accepted this moral case for federalism. Even Edward Heath, the most pro-European, had no vision for Britain in Europe beyond entry.

It is irresponsible to ask, yet again, a country with virtually no interest in such a development to renew its vows to a marriage whose very purpose it cannot abide. And it is irresponsible to the rest of the EU — especially the core countries of Germany, Benelux, Italy and even France — which have a profound need to develop into a confederation.

Yet, oblivious to the incompatibility of British and most continental visions, the old “pragmatic” case for UK membership is trotted out: The EU offers our exporters the single market and our nation crucial influence in the world.

However, Britain will continue to have access to the EU market if it leaves — just as Switzerland does, a country that also sends about half its exports to the EU. Competitiveness, not market access, is Britain’s problem. It has the same access as Germany to the vast Chinese and US markets, but is far less successful in both. Switzerland, with a population smaller than the English Midlands, exports almost as much to Germany from outside the EU as Britain does from within it.

What about influence? Will Britain outside the EU become a nobody? In global trade talks it will suffer most, though the bloc will have strong reasons to co-opt Britain, for example, in free trade talks with the US.

Beyond trade, it is anyway hard to think of a significant global problem over which the EU has exerted decisive influence, from the Israeli-Arab dispute and Bosnia to Russia’s regional conflicts. As to sanctions and other instruments of trade policy, Britain can join EU action, say towards Iran, from the outside almost as well as from within.

Besides, most major UK foreign interventions have been as a US sidekick — most recently in Afghanistan, Iraq and Libya. Can one imagine the US, whatever its warnings to Britain not to leave the union, saying to its number one European military ally: “No, we can’t accept your help in Iraq or Libya if you aren’t in the EU”?

However, how can a pro-European bring himself to think Britain should leave? Because if Britain (ironically, given its own commitment to liberty) repudiates the moral case for the EU, its membership is demoralising both to the country and to the EU. The fudge yet again being urged on Britain by pro-Europeans in all UK parties, the Confederation of British Industry (CBI) employers’ body and now the US, will not go on working. The fall of the Berlin Wall, the resurgence of Germany and the deepening weakness of France have changed everything. There is a move towards a federal Europe, whether or not the Eurozone ends up as a northern enclave around Germany.

Paradoxically, the end of the communist threat to Europe has turned out to be a more powerful spur to its integration than Soviet aggression. From now on, federalism is for real — which is why pressure from the US on Britain to stay in the EU is unwise. There must be a referendum on UK membership and the only honest choice is in or out. Since Britain will never feel comfortable with a federal project — any more than it will as the 51st US state — it should leave this unnatural marriage, which regularly tears apart its main political parties and find a role fit for its lonesome, imaginative and tactically adroit self.

Both the US and EU need Britain as an ally, and it will have a bright future as a semi-independent broker in world affairs. The greatest advance in Middle East peace for decades — the 1993 Oslo accords — was brokered by Norway, precisely because of its independence. If Norway can do it, Britain can do it in spades.

— Financial Times

Simon May is visiting professor of philosophy at King’s College London and was a cabinet member in the European Commission.