IT WAS in Greece that the infernal euro crisis began just over five years ago. So it is classically fitting that Greece should now be where the denouement may be played out—thanks to the big election win on January 25th for the far-left populist Syriza party led by Alexis Tsipras (see article). By demanding a big cut in Greece’s debt and promising a public-spending spree, Mr Tsipras has thrown down the greatest challenge so far to Europe’s single currency—and thus to Angela Merkel, Germany’s chancellor, who has set the austere path for the continent.

The stakes are high. Although everybody, including Mr Tsipras, insists they want Greece to stay in the euro, there is now a clear threat of Grexit. In 2011-12 Mrs Merkel wavered, but then decided to support the Greeks to keep them in the single currency. She did not want Germany to be blamed for another European disaster, and both northern creditors and southern debtors were nervous about the consequences of a chaotic Greek exit for Europe’s banks and their economies.

This time the odds have changed. Grexit would look more like the Greeks’ fault, Europe’s economy is stronger and 80% of Greece’s debt is in the hands of other governments or official bodies. Above all the politics are different. The Finns and the Dutch, like the Germans, want Greece to stick to promises it made when they twice bailed it out. And in southern Europe centrist governments fear that a successful Greek blackmail would push voters towards their own populist opposition parties, like Spain’s Podemos (see article).

A good answer to a bad question

It could all get very messy. But there are broadly three possible outcomes: the good, the disastrous, and a compromise to kick the can down the road. The history of the euro has always been to defer the pain, but now the battle is about politics not economics—and compromise may be much harder.

Tantalisingly, there is a good solution to be grabbed for both Greece and Europe. Mr Tsipras has got two big things right, and one completely wrong. He is right that Europe’s austerity has been excessive. Mrs Merkel’s policies have been throttling the continent’s economy and have ushered in deflation. The belated launch of quantitative easing (QE) by the European Central Bank admits as much. Mr Tsipras is also right that Greece’s debt, which has risen from 109% to a colossal 175% of GDP over the past six years despite tax rises and spending cuts, is unpayable. Greece should be put into a forgiveness programme just like a bankrupt African country. But Mr Tsipras is wrong to abandon reform at home. His plans to rehire 12,000 public-sector workers, abandon privatisation and introduce a big rise in the minimum wage would all undo Greece’s hard-won gains in competitiveness.

Hence this newspaper’s solution: get Mr Tsipras to junk his crazy socialism and to stick to structural reforms in exchange for debt forgiveness—either by pushing the maturity of Greek debt out even further or, better still, by reducing its face value. Mr Tsipras could vent his leftist urges by breaking up Greece’s cosy protected oligopolies and tackling corruption. The combination of macroeconomic easing with microeconomic structural reform might even provide a model for other countries, like Italy and even France.

A very logical dream—until you wake up and remember that Mr Tsipras probably is a crazy leftwinger and Mrs Merkel can barely accept the existing plans for QE. Hence the second, disastrous outcome: Grexit. Optimists are right that it would now be less painful than in 2012, but it would still hurt.

In Greece it would lead to bust banks, onerous capital controls, more loss of income, unemployment even higher than today’s 25% rate—and the country’s likely exit from the European Union. The knock-on effects of Grexit on the rest of Europe would also be tough. It would immediately trigger doubts over whether Portugal, Spain and even Italy should or could stay in the euro. The euro’s new protections, the banking union and a bail-out fund, are, to put it mildly, untested.

Greece in graphics: the facts and the figures explained So the most likely answer is a temporary fudge—but it is one that is unlikely to last long. If Mr Tsipras gets no debt relief, then he will lose all credibility with Greek voters. But even if he wins only marginal improvements in Greece’s position, other countries are bound to resist. Any changes in the bail-out terms will have to be voted on in some national parliaments, including Finland’s. If they passed, voters in countries like Spain and Portugal would demand an end to their own austerity. Worse still, populists from the right and left in France and Italy, who are not just against austerity but against their countries’ membership of the euro, would be strengthened. And there are technical problems with any fudge. The ECB is adamant that it cannot provide emergency liquidity to Greece’s banks or buy up its bonds unless Mr Tsipras’s government is in an agreed programme with creditors, so any impasse is likely to trigger a run on Greek banks. By stretching out maturities, some of this could be avoided—but that may be too little for Mr Tsipras and too much for Mrs Merkel.

Hello to Berlin

So in the end, Greece will probably force Europe to make some hard choices. With luck it will be towards the good outcome outlined above. Greek voters may be living in a fool’s paradise if they think Mr Tsipras can deliver what he says, but the Germans too have to look at the consequences of their obstinacy. Five years after the onset of the euro crisis, southern euro-zone countries remain stuck with near-zero growth and blisteringly high unemployment. Deflation is setting in, so debt burdens rise despite fiscal austerity. When policies are delivering such bad outcomes, a revolt by Greek voters was both predictable and understandable.