SISYPHUS was condemned to push a boulder uphill only to watch it roll down again. Yet an eternity of boulder-shoving seems purposeful next to the unending labour of keeping Greece in the euro zone and out of default. It is nearly seven years since the first Greek bail-out. A second rescue package soon followed. In 2015 Greece came close to dropping out of the euro before its newish prime minister, Alexis Tsipras, buckled down to the task of pruning the budget as part of a third bail-out. Now a Greek disaster is looming all over again. This time the source of the trouble is a row among the two main creditors over how to assess Greece’s public debt (see article). The stand-off threatens a payment to Greece from the euro zone’s bail-out fund, the European Stability Mechanism (ESM), which would redeem €6.3bn ($6.7bn) of bonds that are due in July. If the money is withheld, Greece will be in default. Sooner or later, Grexit would be hard to avoid.

Hopes of an agreement before a meeting of euro-zone finance ministers on February 20th have evaporated. A deal is in everyone’s interest, and the Greek crisis has a history of last-minute fixes. Sadly, there are reasons to fear that brinkmanship and politics will get in the way.

Before this new impasse, Greece’s economy was improving. Deposits had trickled back to the banks, letting the European Central Bank (ECB) cut its emergency lending. GDP has risen fitfully after years of persistent decline. Unemployment is still woefully high, at 23%, but is down from a peak of 28%. And Greece comfortably surpassed a crucial target by recording a primary budget surplus (which excludes debt-interest costs) above 0.5% of GDP in 2016.

Still, the economy is too weak to withstand a fresh bout of austerity. Almost half of bank loans are non-performing. Investment is feeble. Credit to small firms, the backbone of the economy, is scarce. Business rules and tax codes are unfriendly and changeable. In addition, Greece’s primary surplus is the result of policies that are inefficient and unfair. Marginal tax rates have been increased while exemptions proliferate, a recipe for Greeks to exercise their mastery of tax avoidance. More than half of wage earners in Greece are still exempt from income tax. Essential spending has been cut even as pensions remain generous. A newly retired Greek receives 81% of average wages, compared with 43% for a German.

Against this backdrop, a row between Greece’s creditors has been brewing. At issue is the IMF’s role in the bail-out. Germany and the Netherlands do not trust the European Commission to police Greece, and have made the fund’s involvement a condition of their support. The fund is reluctant. Its officials reckon that the programme’s target of a sustained 3.5% primary budget surplus might push the Greek economy into recession. They would prefer to delay further austerity and to insist on more tenable fiscal measures that would do less harm. Europe thinks the IMF is too gloomy about Greece’s prospects.

These are not the only sticking-points. By the IMF’s own rules, it cannot take part unless it believes that the bail-out will leave a debt burden that is “sustainable”—one that is steadily falling and easily financed. For the Greek bail-out to pass muster would require a commitment to debt relief from the euro-zone partners. But an explicit pledge to let Greece off its debts would be politically poisonous, because it might increase support for anti-EU parties ahead of elections in the Netherlands, France and Germany. Instead Klaus Regling, the ESM’s boss, argues that the euro zone’s evident “solidarity” with Greece (the ESM holds two-thirds of its debt, much of it at long maturities and low rates) is enough to make the sums add up.

This is a farce. Most of the bonds due for redemption in July belong to the ECB. In essence, therefore, Greece’s creditors are arguing among themselves over whether to agree on a payment from one euro-zone institution to another. The shape of a compromise is plain. Greece will have to pass legislation that commits the government to reducing pensions and income-tax allowances after 2018. European creditors will need to pledge to finance Greece’s debts at today’s low interest rates. And the IMF will have to stomach a higher fiscal-surplus target for Greece than it would like.

Boulder games

Yet everything could still go wrong. Mr Tsipras seems to think he can wait for the IMF, egged on by America under Donald Trump, to abandon its stewardship of the bail-out. The resulting uncertainty will set back Greece’s fragile economy. Growing political turmoil in Germany and France could also make a deal harder to reach. A long stand-off risks seeing Greece roll down to the bottom again. Nobody would benefit.