Republicans clearly sense that they are being outmaneuvered in the fiscal talks by the Obama administration, unable to stop the inevitable rise in tax rates for the rich. But they have one last card to play and they intend to use it, knowing it will endanger economic progress: They are threatening once again to default on the credit of the United States if President Obama doesn’t do their bidding.

Party officials say that if they do not reach an acceptable deal with the White House this month, they will wait until the country reaches the debt ceiling early next year, then refuse to lift it until they get their way on cuts to spending and taxes, The Times reported on Wednesday.

Apparently, they learned nothing from the debacle of 2011, when they first tried this extortionate tactic. The nation lost its AAA credit rating, stock values plunged, and the approval rating of Congress sank to historically low levels. Republicans portray themselves as spending hawks, but that episode cost the Treasury $1.3 billion in higher borrowing costs in 2011, according to the Government Accountability Office. Last week, the Bipartisan Policy Center estimated that the 10-year cost of higher interest rates was $18.9 billion.

Republicans savor that potential catastrophe, caring only that the threat won them $2 trillion in spending cuts over a decade from Mr. Obama. Now they want to do it again, and this time they want something the last agreement missed: big cuts to Social Security, Medicare, Medicaid and other programs that primarily benefit middle- and low-income people. Grover Norquist, who leads the party’s anti-tax cult, even suggested that the debt limit be raised only enough to get through a month at a time, so that Republicans can maximize their blackmail power.