GREECE has long seemed a decent bet to crash out of the euro zone, and perhaps also the European Union. But during the current election campaign in Britain, Britain's exit (or a "Brexit") from the EU has also started to seem a real possibility. David Cameron, the prime minister, has promised an in/out referendum vote on Britain’s EU membership by the end of 2017 if the Conservatives remain in power on May 7th. Several other smaller parties, notably the UK Independence Party (UKIP), are campaigning specifically to leave the EU. Moreover, polls show that any referendum would be an extremely tight one. Why might Britain be leaving the EU, and how would it happen?
