Even if the euro stabilizes, that kind of treaty move would institutionalize a "two-speed Europe" — of the euro zone and the others — with different rules and conditions, which many members oppose.
The euro had stabilized, and markets were less volatile, but worries about a new banking collapse remained.
As expected, the European Central Bank left its benchmark interest rate unchanged at 4.75percentt because inflation was cooling and the euro had stabilized.
But as soon as the euro is stabilized, Europe's leaders should start "giving popular sovereignty some voice in other aspects of the E.U. project".
Those developments allowed Mr. Laming to conclude that the euro had stabilized and that oil prices had fallen enough to diminish the chances of a hard landing for the American economy.
The British pound tumbled on Friday against the U.S. dollar and the euro before stabilizing, down 1.7 and 1.4 percent against the two currencies respectively.
"I don't believe that the euro would be stabilized over the long term by ignoring constitutions and treaties," Mr. Weidmann said during an interview.
"They are realistic enough to have learned their lessons, which is that if we want to have a stabilized euro we have to do much more we have to add new elements to the system," said Mr. Fritz-Vannahme.
FRANKFURT — The euro zone has stabilized markedly in the last year, Mario Draghi, the president of the European Central Bank, said on Thursday, as he offered a slightly more upbeat assessment of the prospects for growth.
It is entirely possible to stabilize euro bond markets and save the euro with a large increase of the European Financial Stability Facility and/or a substantial increase of the European Central Bank's purchase of government bonds.
