"the Greeks have to leave the euro zone"

According to Die Welt this week, the only way that Greece can be saved is that it be uncoupled from the Euro. It makes it clear that trying to impose discipline from without will fail,

 Whatever the euro summit agreed and whatever the next one will agree -- we won't get a European austerity commissioner equipped with authoritative powers."
"Countries in crisis can't be transformed into protectorates. An EU fiscal commissioner wouldn't be able to achieve much unless he had the powers of an occupying statute."
"The conclusion almost sounds paradoxical: In order to rescue their state and their sovereignty, the Greeks have to leave the euro zone. They owe it to themselves. They have to go their own way with the freedom afforded by exchange rate movements and with a strong stimulus of economic growth."

Well you can't say fairer than that.