Oh. You didn't know that Switzerland was part of the European Monetary Union? You thought that the Swiss used their own currency, the Swiss franc? In a definitional sense only, you are correct. Within its monopolized currency area, the political boundaries of Switzerland, the Swiss franc is legal tender. But for approximately three years the Swiss National Bank has maintained a Swiss franc to euro ratio of 1.2 francs per euro. The usual suspects, exporters, were the driving political force behind the SNB's policy. They feared fewer sales to eurozone countries should the franc cost more in euro terms. This policy made the European Central Bank (ECB) the determinant of monetary policy in Switzerland and relegated the Swiss National Bank to the mechanical role of currency board. When the Swiss franc started to appreciate against the euro, meaning that buyers were willing to accept fewer than 1.2 francs per euro, the Swiss National Bank printed francs and bought euros. Over the last three years as demand for Swiss francs from euro holders increased, the SNB's balance sheet exploded with new euro reserves. However, as the world now knows, in a surprise move the SNB abandoned its currency peg policy. Today the franc exchanges approximately one for one with the euro, meaning that the franc has appreciated by approximately twenty percent against the euro.
As far as I know the SNB has made no official announcement of the reason for its surprise move. I suspect that the Swiss people had made themselves heard that they feared inflation from the ECB's imminent quantitative easing policy. The Swiss gold referendum on November 30 would have required their central bank to hold a fixed percent of reserves in the form of gold. It was defeated only after the major political parties and the SNB amounted a concerted anti-referendum blitz. Still in control of their own currency, it was a relatively simple matter for Switzerland, in effect, to veto the ECB's proposed policy by abandoning the currency peg. This shows the rest of Europe that at least one nation does not fear returning to full control of its currency nor does it fear the consequences of a temporary drop in exports. (The drop will be temporary, because Swiss import prices will fall and eurozone users will be awash with depreciated euros and willing to pay more for the Swiss franc.)
The lesson is clear. If Switzerland can retake control of its money, so can any eurozone nation. The process may take longer, as the country reissues its own currency and re-denominates its bank accounts in local currency terms, but it can be done. Already there are reports that the Danish central bank is contemplating abandoning its currency peg of approximately 7.5 krone per euro. If the sky does not fall on Switzerland and Denmark, other nations may follow. Does anyone know how to say deutsche mark?