It has been obvious for some time that the creation of the euro was a terrible mistake. Europe never had the preconditions for a successful single currency — above all, the kind of fiscal and banking union that, for example, ensures that when a housing bubble in Florida bursts, Washington automatically protects seniors against any threat to their medical care or their bank deposits.

Leaving a currency union is, however, a much harder and more frightening decision than never entering in the first place, and until now even the Continent’s most troubled economies have repeatedly stepped back from the brink. Again and again, governments have submitted to creditors’ demands for harsh austerity, while the European Central Bank has managed to contain market panic.

But the situation in Greece has now reached what looks like a point of no return. Banks are temporarily closed and the government has imposed capital controls — limits on the movement of funds out of the country. It seems highly likely that the government will soon have to start paying pensions and wages in scrip, in effect creating a parallel currency. And next week the country will hold a referendum on whether to accept the demands of the “troika” — the institutions representing creditor interests — for yet more austerity.

Greece should vote “no,” and the Greek government should be ready, if necessary, to leave the euro.

To understand why I say this, you need to realize that most — not all, but most — of what you’ve heard about Greek profligacy and irresponsibility is false. Yes, the Greek government was spending beyond its means in the late 2000s. But since then it has repeatedly slashed spending and raised taxes. Government employment has fallen more than 25 percent, and pensions (which were indeed much too generous) have been cut sharply. If you add up all the austerity measures, they have been more than enough to eliminate the original deficit and turn it into a large surplus.