Greece is tiny, its economy only 3 per cent of the EU. But just as the world appeared to be clawing its way out of financial turmoil and recession, Greece reminded the markets that countries, as well as banks, can go bust. The EU has changed its poorer members less than its founders imagined. Perhaps this crisis—the most serious in the EU since its creation, according to Angela Merkel—will finally persuade Greece, and the other weaker economies, to make the reforms they have ducked since joining the euro.