IT IS not a fudge, but it is still a failure. The euro zone’s bail-out of Cyprus, which was sealed in the early hours of Saturday, did get the bill for creditor countries down from €17 billion to €10 billion, as had been rumoured. But the way it did so was somewhat unexpected. Almost €6 billion of the savings for taxpayers in euro-zone countries came from losses imposed on depositors in Cyprus’s outsize banks. A one-off 9.9% levy will be imposed on all deposits over the insurance threshold of €100,000 before banks reopen after a bank holiday on Monday. That idea had been in the air for a while, not least because a lot of those uninsured deposits came from outside Cyprus, and from Russia in particular. The politics of saving wealthy Russians with money loaned by thrifty Germans were always going to be tricky.

What had not been anticipated was a 6.75% loss for savers with deposits in Cypriot banks below the insurance ceiling. Cypriots woke up this morning to find bank branches closed to them. By the time they will be able to get at their money, it will be too late. The offer of equity in banks to replace the value of their savings is meant to be a balm but it’s not a choice they would have made. Why this decision was taken is not yet clear. The most plausible explanation is that the Cypriot government itself preferred to spread the pain rather than wipe out non-resident depositors and jeopardise its long-term prospects as an offshore financial centre for Russian and other money.

Whatever the rationale, it is a mistake for three reasons. The first error is to reawaken contagion risk elsewhere in the euro zone. Depositors have come through the financial crisis largely unscathed. Now they have been bailed in, some of them in breach of an explicit promise that they can be sure of getting their money back even if a bank goes belly-up.

Euro-zone leaders will spin the deal as reflecting the unique circumstances surrounding Cyprus, just as they did the Greek debt restructuring last year. But if you were a depositor in a peripheral country that looked like it needed more money from the euro zone, what would your calculation be? That you would never be treated like the people in Cyprus, or that a precedent had been set which reflected the consistent demands of creditor countries for burden-sharing? The chances of big, destabilising movements of money (into cash, if not into other banks) have just shot up.

The second error is one of equity. There is an argument to be made over the principles of bailing in uninsured depositors. And there is a case for hitting everyone in Cypriot banks before any taxpayer in another country. But there is no moral imperative for whacking Cypriot widows and leaving senior bank bondholders untouched, as appears to be the case here; or not imposing any losses on sovereign-debt investors in Cyprus; or protecting depositors in the Greek operations of Cypriot banks, as has also happened. The euro zone may cloak this bail-out in the language of fairness but it is a highly selective treatment. Indeed, the euro zone’s insistence that this is a one-off makes that perfectly plain: with enough foreigners at risk and a small enough country to push around, you get an outcome like Cyprus. (That is one reason why people are now wondering about the implications of this deal for little Latvia, also home to lots of Russian money and itself due to join the euro zone in 2014.)

The final error is strategic. The Cypriot deal has no coherence in the larger context. The euro crisis has been in abeyance for a few months, thanks largely to the readiness of the European Central Bank to intervene to help struggling countries. The ECB’s price for helping countries is to insist they go into a bail-out programme. The political price of going into a programme has just gone up, so the ECB’s safety net looks a little thinner.

The bail-out appears to move Europe further away from the institutional reforms that are needed to resolve the crisis once and for all. Rather than using the European Stability Mechanism to recapitalise banks, and thereby weaken the link between banks and their governments, the euro zone continues to equate bank bail-outs with sovereign bail-outs. As for debt mutualisation, after imposing losses on local depositors, the price of support from the rest of Europe is arguably costlier now than it ever has been.

It is also hard to square this outcome with the ongoing overhaul of finance. The direction of efforts to improve banks’ liquidity position is to encourage them to hold more deposits; the aim of bail-in legislation planned to come into force by 2018 is to make senior debt absorb losses in the event of a bank failure. The logic behind both of these reform initiatives is that bank deposits have two, contradictory properties. They are both sticky, because they are insured; and they are flighty, because they can be pulled instantly. So deposits are a good source of funding provided they never run. The Cyprus bail-out makes this confidence trick harder to pull off.

Other than that, it is a really good deal.