Its not the amount of debt, but the ability to pay it back. This is where Greece has failed miserably. They collect next to no taxes, export next to bugger all, and haven't a hope in hell of paying it back in our lifetime.
Its like The Eurozone had a great big BBQ party, most of the nations brought along burgers, steak, some stella and a couple of bottles of plonk. Greece however rocked up with a half full bottle of blue nun, and yet we still let them have an equal share of the party food and drink. Now its time to pay the supermarket bill, they find themselves in the sh*t and looking for the exit.
Yes I agree but the problem with the eurozone is that the chain is only as strong as the weakest link, and when under pressure there are alot of weak links.
If I was Germany I would leave the eurozone before everyone else does.