How difficult is it for a country to leave the Euro?

Learned Minds can recite catalogues full of reasons why it is very difficult, even impossible, for a member state of the Euro Zone to abandon the Euro. But all the legal niceties will count for little if the decision is made to cut the Gordian Knot. While to Euro as a practical instrument is quite useful for tourists as well as businesses the boost to the economies to the member states was at best marginal during the past ten years. These days the exchange of currencies is nearly frictionless and very cheap in the day of the Internet - for private people and even more so for business purposes. But the argument that the exit from the Euro Zone would be extremely difficult and take a long time to prepare is difficult to swallow. It should be possible to declare on any weekend that the exit has been decided and that all bank accounts, financial assets and liabilities will be frozen and converted into the new currency from that moment on. Unfortunately, this analysis makes it even more likely that the Euro Zone will lose one of its members at some point in the future because any sane investor or business manager will henceforth take this possibility into account when making decisions.