This article by Steve Randy Waldman (linked by Brad Delong and Mark Thoma) is the most historically persuasive and frightening explanation (among many) that I have seen on EU v. Greece:
Europe’s elites — its politicians and civil servants, its bankers and financiers — deflected the blame in the worst possible way. They turned a systemic problem of financial architecture into a dispute between European nations. They brought back the very ghosts their predecessors spent half a century trying to dispell. Shame. Shame. Shame. Shame.
...Having recast a crisis caused by a combustible mix of regulatory failure and elite venality into a morality play about profligate Greeks who must be punished, Eurocrats are now engaged in what might be described as “loan-shark theater”. They are putting on a show for the electorates they inflamed in order to preserve their own prestige.