Europe.
On the long flight back from Las Vegas last month, I found the time to read Boris Johnson's 'Lend me your ears'; a collection of some of his articles. In an footnote to one piece, he encapsulates in seven words the problem facing those who want further EU integration: 'Europe is not a natural political unit'.

He's right. Elsewhere he points out that we still don't know Europe's borders. Should the Ukraine be able to join? Turkey? Belarus? What about Russia? Much of Russia is certainly European in character, but we can't just choose the bits we want. We have to take the whole thing all the way to Vladivostok, or none at all.

But his seven-word rebuttal is more basic than that. There is no natural sense in which Europeans share common day-to-day political interests. Can you name the prime minister of Austria? Do you know the inflation rate of Belgium? Can you tell me the unemployment rate in Hungary? Do you care?

When European elections come, people vote on almost purely national issues, making a complete mockery of the European Parliament. Can you name your MEP? If you can, do you know what he or she has done for the last two years? If you are drawing a blank to these questions, don't worry. You're normal. What is abnormal is pretending that people are interested in the day to day business of politics in other countries when it's clear that they aren't.

I'm not an advocate of withdrawal from the EU. I won't vote for UKIP. I just want Europe's politicians to recognise that while there is widespread support for free trade across Europe and for visa-free travel, there is no broad base of support for further political integration.