Hari is probably right: "Pacta Sunt Servanda", ie: treaties go even above the constitution. Though it depends a bit on the status of international treaties in the German constitution. If it is possible to invalidate a treaty that is not constitutional, then I guess the German constitutional court could declare the Lisbon treaty void. That seems preposterous, and I hope the German constitution is not like that.



However: if the ECB makes a 'loss', that does NOT mean that the EU countries necessarily need to raise that amount of money from taxes or debt to pay off that loss. The ECB has the power to print money from nothing. The ECB is a central bank. It has printed money to buy up european sovereign debt. If one of those sovereigns goes bust, it doesn't hurt the ECB. Nor should it need to hurt the fiscal situation of any of the other Euro countries. Unless they insist to run up some debt and give it to the ECB. But if they insist that they will .. they why are they so afraid of even the chance that it might happen? Let's hypothesise Greece goes bankrupt (and doesn't necessarily leave the Euro zone). Then what? Would the other Euro countries really insist on paying the ECB for those losses? Or would they rather change the Lisbon treaty and not pay for the bankruptcy of Greece? Of would they find the freedom to interprete the Lisbon treaty more freely to say that is what it said all along?