If Greece redominates all its debts in cut price drachmas, the ECB and its backers – in particular the German Bundesbank – will take a terrible hit, but it won’t be terminal. The Bundesbank would most likely simply write off its Target 2 lending to Greece, which would certainly be a major curiosity given its abhorrence of debt monetisation but wouldn’t of itself destroy either the Bundesbank or the euro.
The threat comes instead from market contagion to other eurozone countries worst hit by the debt crisis. To Germany, Greece has always been a special case, a nation which cheated its way into the euro, whose citizens are lazy and won’t pay their taxes, and is in any case basically ungovernable. There is a very different attitude to Spain and Italy. Germany’s determination to make the rest of the eurozone work should not be underestimated.
The trouble is that once one has left, and the principle has been established that it is indeed possible to leave the euro, it’s going to be tough to impossible to contain the crippling capital flight which is certain to set in elsewhere. Greece is just the canary in the mineshaft, an outrider for the much wider problem of imbalances and divergent competitiveness.