What would you call a country that called for "a structure under which [Europe] can dwell in peace, in safety and in freedom ... a kind of United States of Europe" at the end of WWII (Winston Churchill, 1946), but refused to join that structure when its European neighbours actually began building it (European Economic Community, 1957)?
What would you call that country if it changed its mind and asked to join the EEC in 1961, a goal it finally achieved in 1973 under Conservative PM Edward Heath - only to demand a renegotiation of its terms of membership and hold an in-out referendum on EEC membership under a Labour government two years later?
What would you say if that country then demanded another renegotiation of the terms of membership under Conservative PM Margaret Thatcher in 1984, and insisted on opting out of the planned single currency when the countries of the European Community signed the Treaty of Maastricht in 1992?
And what would you say about that country's behaviour if another Conservative PM, David Cameron, demanded another renegotiation on the terms of membership in what is now called the European Union in 2013, and promised another referendum once the results were known? The word "ambivalent" would certainly spring to mind. "Capricious" also has a strong claim. But the adjective that really sums up Britain's behaviour in its 70-year love-hate relationship with the European project is "petulant".
There's going to be another referendum on whether the UK should stay in the EU on June 23. Not that Cameron wants to leave. His 2013 promise of a referendum was an attempt to steal votes from the United Kingdom Independence Party, which wanted to leave, in the 2015 election.
But Cameron couldn't walk away from his promise after he won the election, because half his party wants to leave the EU. Jeremy Corbyn, the new leader of the Labour Party, is at best lukewarm about the EU, viewing it essentially as a capitalist plot with some positive side-effects. And recent opinion polls suggest the referendum could go either way.
These are not the best of times for the EU. It has not responded well to the recent wave of mostly Middle Eastern refugees. It is suffering from chronic low growth and high unemployment (although the UK is doing quite well on both fronts). It is becoming clear that the adoption of the euro by 19 EU countries was a mistake.
There is, therefore, a lot of disillusionment about the EU. Some fear "Brexit" (a British exit from the Union) would unravel all the other deals and compromises that went into the construction of the EU. But why are the British always the most disaffected ones?
All the countries on the west coast of Europe lost overseas empires in the decades after the WWII, and Britain is not the only one to cling to delusions of grandeur in the aftermath. France, too, has a highly inflated view of its own importance. But the French understand the cost of European disunity much better than the British, because they paid a higher price.
It has to do with the fact that Britain is an island. Almost every other European country has seen serious fighting on its own soil in the past 100 years. About half of them have been partly or wholly occupied by foreign troops for long periods. Whereas Britain has not been successfully invaded for almost 1,000 years.
Britain is not alone in seeing the follies of the EU bureaucracy and resenting the cost of the compromises that have to be made to keep the enterprise alive. It is alone, or almost alone, in seeing European unity purely as an optional project, to be reassessed from time to time by calculating its economic benefits and weighing them against its political and emotional costs for Britain.
Emotional costs? Yes, and this is where the petulance comes from. There is a fantasy, still prevalent in England, that it could have a much more satisfying future as a fully independent player, unshackled from the stodgy EU living by its wits as a swashbuckling global trader.
This romantic vision is not shared by the Scots, who would certainly break away if English votes took the UK out of the EU. But an independent Scotland might find it hard to claim EU membership after the divorce, as Madrid would not want a precedent set for Catalonian separatists.
Most British leaders have worked hard to manage the inflated expectations of English super-patriots and keep the country on track. Cameron has dropped the ball and the consequences for both Britain and Europe may be serious.
Gwynne Dyer is an independent journalist whose articles are published in 45 countries.