You are correct. However, I read that a possible way to get around the EU Constitution on this is by instituting a two-tier Euro; a Southern Euro and a Northern Euro, each allowed to float up or down to it's natural value independent of the other. It's essentially a method of creating separate monetary systems while staying within the EU's legal structure. Guess it may be the next best thing to booting the PIIGS out and letting them flounder on the backs of their own curriences. Don't know......
Months ago a freeper posted about such a plan and said it was already developed and ready to go.
At the time it sounded like tin hat stuff.