When, in 1961, the Macmillan Government announced Britain's intention to seek admission to the new Common Market, the prospect of Britain entering what is now the EU stunned Australia. Dismayed, Prime Minister Sir Robert Menzies called the announcement 'the most important in time of peace in my lifetime'.

Culturally, politically and economically, the link with Britain was far and away Australia's most important. Ties of kin and language, combined with the experience of standing side-by-side through two world wars, made the relationship like no other. Or was it? Suddenly, in 1961, no one was sure.

Six decades later, the same question is being asked of Britain's 'special relationship' with the US. The relationship is founded on similar ties of blood, language and memories of shared wartime sacrifice, and until now it had been assumed to be just as special. But among Britain's Eurosceptics, typically true believers in the US-UK 'Special Relationship', President Barack Obama's effort last week to dissuade British voters from voting to leave the EU has provoked outrage, disbelief and defiance.

At a Downing Street press conference with British Prime Minister David Cameron on Friday, Obama delivered a two-part warning. The first was economic.

Britain, he warned, was running a huge risk, which Washington would do nothing to help mitigate. 'Special relationship' notwithstanding, Britain would find itself 'at the back of the queue' when it came to negotiating a separate trade deal with Washington. When it came to the 'heavy lift' of concluding such an agreement, US eyes would be on a deal with 'a big bloc'. Dealing with a single nation like Britain on its own would be 'hugely inefficient'. (In reality, the US has free trade agreements with such titans of global commerce as Peru, Morocco, Oman and Chile. Australia has one too. Britain, by contrast, is the world's fifth-largest economy and America's biggest foreign investor.)

Obama's second argument was political. Britain's membership of the EU doesn't reduce Britain's influence in the world, it magnifies it.

This takes us to the heart of the pro-Brexit argument. What price the nation's soul? Traditionally, British foreign policy was built on securing the independence of parliament, Protestantism and free trade. Together, these three institutions underpinned Britain's distinctive national identity.

If you are post-modern enough, you might believe Britain's EU membership has served these goals well.

After all, the EU exists to export to the historically less fortunate countries of the Continent, with their various mixtures of authoritarianism, Catholicism and corporate mercantilism, the liberal institutions and market-based economies of the modern parliamentary state that first appeared in seventeenth-century England. It propagates those liberal values of open-minded tolerance that are the legacy of that secularised form of Protestant theology embodied in the north European Enlightenment.

Indeed, when Obama said that the EU 'promoted British values', this is essentially what he meant. But it doesn't take much to see how far these 'values' have been disembodied of specific national provenance to fit them out for a continental vocation.

Here the Eurosceptic counter-argument reaches its most passionate, seeing as the European project's ultimate aim the creation of a super-state that would collapse distinctive national histories into an undifferentiated pan-European narrative. Politically, they say, the supra-national Commission does this with its directives to national parliaments, while a European Parliament seeks to call into being a post-national 'European demos'. Culturally and socially, they argue, the unrestricted right of EU citizens to settle, work and draw public benefits in other member-states does this by diluting the link between citizenship, community and state.

The Eurosceptics see Britain as exceptional. For almost 200 years Britain, alone among European states (except Russia), was not just a continental but a global power. The Second World War left three global 'great powers' standing: the British Empire, the Soviet Union and the US. By 1991, that field had narrowed to one, and America's unipolar moment might now have passed. 

A certain symmetry links Britain's campaign to leave the EU with Russia's attempts, twenty-five years after the fall of the Soviet Union, to reassert its unique culture and independence on the world stage. Only in Britain's case, that re-assertion is taking place two generations later and in utterly demilitarised form. Memories of exceptionalism are also dimmer.

At the end of the press conference, Obama was asked whether it was true that he had removed Churchill's bust from the Oval Office. That was true, Obama conceded. But of Churchill, he said, 'I love that guy'.

Yet, though some have tried, it's hard to imagine the historical Churchill advising Britons to stick with the EU as Obama has done. The great wartime prime minister saw Britain's post-war role as deriving from its position at the intersection of three great circles of wealth, power and influence —the US, Europe and the Empire — but subordinate to none.

Britain's partners thwarted that Churchillian vision. The price both of the 'Special Relationship' and admission to Europe  was the loss of the empire which embodied Britain's independent global role. The Americans did it through Lend-Lease and Suez; the Europeans through the tariff wall that all but severed serious economic relations between Britain and the Commonwealth, including Australia.

And yet, as Mr Obama brought home the conditionality of the Special Relationship, Cameron nodded and smiled, as if reveling in the habits of dependency since acquired. Not only Churchill, but Salisbury, Palmerston, Wellington and Pitt must have turned in their graves.
Obama arrived at Downing Street direct from lunch with The Queen at Windsor. This was supposed to lend an air of royal approval to his message. But the effect was to show it up for the novelty it was in Britain's long story.

In a renowned 1947 speech from South Africa, a young Princess Elizabeth committed her 'whole life whether it be long or short' not 'the Special Relationship' or the 'European project' but to the service of 'the great imperial family to which we all belong.'

Menzies was right. The disappearance of what remained of the British world with Britain's final entry into the Common Market in 1973 was one of the great, if largely unmarked, events of the twentieth century. Renegotiating the terms of that demise, reasserting Britain's exceptionalism and its unique historical destiny is ultimately what Brexit is all about.