Fragmenting euro: who will be first?

Italy? Ireland? Spain? Any one could; but would they? Too farfetched maybe, but possible, and indications seem to point to that direction: in Germany people are withdrawing their money but demanding them in German euros.  

Eurozone members print their own euros according to their economy, and the banknotes are identifiable by source. According to the UK’s Telegraph newspaper, Germans are not accepting euros from Italy, Spain, Portugal and Ireland. Does it mean confidence on the euro as a whole is falling?

Though one may think of the euro as a single currency, it is actually a mixture of various currencies supported by their own issuing country’s economy. And as economies differ, the inherent or perceived value of each currency varies also, and this can lead to the people of one country refusing to accept another’s euro notes. Correct or otherwise, people who believe they can lose their life’s savings through wrong choice of currency will simply stick to what they know. Thus a run on a country’s euros is not totally out of this world.  

The greatest cause of the fragmentation of a unified currency is when the danger of one or two countries leaving it was to grow significantly. Faint rumors have circulated, for example, of Italy departing the union but no effect had been felt. The economic difficulties some countries are experiencing are bound to grow worse before long, so investors would be wise to look ahead. This can be the biggest threat to the unified currency in its short existence.  

In the past years, the financial systems of Spain, Ireland and Greece expanded vigorously. A large menu of financial products and low interest rates combined to encourage construction, housing and consumer spending, in the scales that has been unknown before. But the recent tightening of credit caused the economies of Portugal, Italy, Greece and Spain (PIGS) as well as Ireland to suffer. Continued low-interest credit will sustain their economic impetus, but the ECB is looking from the total perspective and cannot grant it in an effort to counter high inflation rates Europe-wide.
The most obvious move for these countries then would be to leave the unified currency and devalue their own, to boost production and create more jobs, and thus strengthen their home economy. But that will leave a fragmented euro and most probably a European economy in shambles. Could any member-country endure that, or would the ECB even allow it?

Yet, if supporting a strong euro and unified currency will mean a crippled national economy, how long will it take before a vote-courting politician think about leaving the euro? Not very long, many would like to think.