The continuing saga of Greece and its creditors is more tragic than comic. But watching it, I am reminded of that old line about the recurring travails of Laurel and Hardy: “Well, here’s another nice mess you’ve gotten me into!” For the problems facing Europe today are not sui generis. They are merely the latest installment of a story that has been unfolding for many decades.

Let’s begin by flashing back to the middle of the 1990s. If you travel around Europe, you find each nation with its own currency — francs in France, marks in Germany, pesetas in Spain, and drachmas in Greece. But change is in the works. Within a few years, much of Europe is trading a single currency, the euro. Over time, more nations join the currency union. Today 19 European nations use the euro as their sole currency, including (at least for now) Greece.

When the euro was introduced, many economists were skeptical about the change. One skeptic was Milton Friedman, the Nobel laureate who dominated much macroeconomic debate in the second half of the 20th century.

In 1997 he wrote: “Europe’s common market exemplifies a situation that is unfavorable to a common currency. It is composed of separate nations, whose residents speak different languages, have different customs and have far greater loyalty and attachment to their own country than to the common market or to the idea of ‘Europe.’ ”