Lets assume for a moment that Greece defaults. In that case the Greek banking system would certainly collapse (assuming the ECB suspends its emergency liquidity assistance (ELA) because bad debts already on their balance sheets exceed tangible equity by a substantial margin. If that assistance is withdrawn, some €80bn of ELA will be lost. Furthermore, TARGET2 2 settlement imbalances at the other Eurozone central banks, which have arisen through capital flight from Greece and which are guaranteed by the ECB, total a further €42bn. This leaves the ECB in the hole for €122bn. Unfortunately, the ECB’s equity capital plus reserves total only €96bn, so a Greek default would expose the euro’s issuing bank to be woefully under-capitalised.
Therefore, if Greece defaults we would at least expect the validity of this relatively new euro to be challenged in the foreign exchange markets. Even if the ECB decided to rescue what it could from a Greek default by rearranging the order of bank creditors in its favour through a bail-in, it would still have to make substantial provisions from its own inadequate capital base. For this reason, rather than risk exposing the ECB as undercapitalised, it seems likely that Greece will be permitted to win its game of chicken against the Eurozone, forcing the other Eurozone states to come up with enough money to pay off maturing debt and cover public sector wages.