Greek Default Would Nuke Entire European Sovereign Market

How do you get a triple-A rating on a bond backed entirely by loans to junk-rated sovereign borrowers? Well, the governments guarantee the bonds, and because they are unfunded off-balance-sheet liabilities, they aren't counted in their debt burdens--unless borrowers default... The strength of these guarantees is untested. Would the German Bundestag vote tomorrow to raise €35 billion by selling Bunds, the government debt, to cover Germany's share of ESM losses on Greek bonds? That seems improbable...

A hard default would produce other losses to be covered. The ECB would have to be recapitalized after it writes off the €89 billion it has loaned the Greek banks to keep them liquid. The ECB would need to call for a capital contribution from its shareholders--the governments.

And don't forget that Greek banks owe the Target2 bank clearinghouse, a key link in the interbank payment system, an estimated €100 billion. The governments are on the hook to make good that shortfall, too. The cash required to cover these contingencies would have to be funded with new bond sales.