The referendum called by Greece’s prime minister is a bad idea, but at this stage it’s about the best available. Greek banks have been shut down to avoid a meltdown; bailout talks with European creditors are frozen; Athens does not have the money to pay 1.6 billion euros due to the International Monetary Fund on Tuesday, threatening default and withdrawal from the euro.

So, confronted with conditions from the lenders that he dismissed as “insulting,” Prime Minister Alexis Tsipras made the surprise announcement on Saturday that he was putting the matter before Greek voters in a referendum to be held July 5.

Putting so complex and fateful a question on such short notice to a nation already so confused and battered is fraught with danger. But given the huge consequences of what is about to happen, the Greeks deserve a chance to say whether they want to stay in the euro, with all the continuing sacrifice that entails, or whether they are prepared for the near-term calamity and long-term unknowns of opting out. At the very least, Greece’s creditors should extend their payment deadlines long enough to hear what the Greek voters say.

The referendum question, released on Monday, will be perplexing to voters, but it doesn’t really matter. The details of the demands over which the talks have collapsed, mostly dealing with pensions and value-added taxes, are not what the endgame is about. At this point, the long-running accusations filling German and Greek tabloids — that the spendthrift Greeks should be taught to live by European rules; that the relentless austerity demanded by Germany and other lenders has served only to destroy Greece’s economy and its ability to pay back its gargantuan debts — don’t matter much.

The question before the Greeks is whether they are prepared to abandon the euro. That is also the question that Chancellor Angela Merkel of Germany, President François Hollande of France, Christine Lagarde, the managing director of the I.M.F., and other members of the eurozone must decide.