Which would rapidly approach equivalence to a New Deutschemark.

Germany has itself in the Euro trap just as strongly as the PIIGS. If they go under, how will Germany keep its currency down and where will it export to?

Seriously, Greece is a small and fairly unimportant part of the European economy.

The Euro collapsing is an apocalyptic scenario that requires quite a lot of things to go wrong. Much more than just Greece.

I agree that it would be an apocalyptic scenario and would require a lot of things to go wrong. But if every eurozone member only thinks about its immediate interests instead of working together and acting in a decisive manner, everything could really go wrong.