Southern European states can retain the euro.
1) Germany leaves and sees appreciation of their currency effecting their export
2) Southern countries keep the euro and see a weaker euro in-turn lowering their debt because it’s denominated in euro.
3) weaker euro makes southern countries competitive, productive and increases their export and bolstering their foreign currency reserve.
The only problem is France, Germany needs to bailout France by giving 300% of german GDP or 10% of German GDP for a indefinitely, which is equivalent to 7 trillion dollar.
Here is the fun part, that 7 trillion dollar is roughly equivalent to the reparations imposed upon Germany with the Versailles treaty which led to Hyperinflation in the Weimar Republic and gave us Nazi Germany.





