Suddenly, it has become easy to see how the euro — that grand, flawed experiment in monetary union without political union — could come apart at the seams. We’re not talking about a distant prospect, either. Things could fall apart with stunning speed, in a matter of months, not years. And the costs — both economic and, arguably even more important, political — could be huge.
Paul Krugman: The Euro Can Still Be Saved -- If European Leaders Make Major Changes Now