The former German foreign minister Joschka Fischer has a revealing op-ed in today’s Süddeutsche Zeitung (link in German, h/t @yascha_mounk). Although his argument is not new, Fischer states the dilemma facing Europe more sharply than other public figures in Germany have done. Either Europe must establish “a fiscal union, and that means Germany must guarantee the financial survival of the Eurozone with its economic power and resources: unlimited purchase of bonds from the countries in crisis through the ECB, Europeanization of national debts by means of Eurobonds, and a stimulus program in order to prevent a depression in the Eurozone and generate growth.” Or the Euro will have to be abandoned.

Fischer’s service is to puncture the illusion that it’s possible to have both the Euro and fiscal independence. Saving the Euro means a major and continuing financial burden for Europe’s most powerful state. Allowing it to fall apart will also cost a fortune, although it’s unclear whether it would lead to a worldwide depression, as Fischer asserts. It’s no good to recall that the Germans were promised that they would never have to bankroll the Spanish and the Italians. They now face the choice between two policies of uncertain outcome: bailing out their junior partners and trying to swim for safety by themselves.

For Fischer, a “good European” of long standing, the right course is clear: Germany must identify itself unreservedly with the European Union. But his argument is ultimately moral rather than economic: “In the 20th Century, Germany twice used war to the point of crime and genocide to destroy the European order in order to subordinate the continent. But Germany drew the correct consequences from those experiences. It was only because of convincing change and the integration of this great country in the center of the continent into the West and the EU that there was agreement to German unity.” For Fischer, then, Germany has a duty to become the banker of a United States of Europe.

Fischer’s probably right that German policy can’t be determined on purely economic grounds. The long-term consequences of letting the Southern European countries go broke are too unpredictable for a simple comparison of costs and benefits. But he’s wrong if he thinks moral appeals will cut much ice with the German government or public. Most Germans are sick of being told what they must do to expiate their parents’ and grandparents’ guilt.

But there’s another principle that might provide a more useful standard for decision: the ideal of self-government. The test of German policy—and that of other European countries—shouldn’t be what European integration is likely to cost (or to pay).  It’s whether integration is compatible with national sovereignty. Germans shouldn’t have to pay the bills for Greece, Italy, and Spain. But they also shouldn’t impose their own ideas about how an economy ought to be run—or vice versa. One lesson of the wars of the 20th century is that peoples will pay an enormous price for the opportunity to govern themselves. In the 21st century, that means accepting the costs of letting the Euro die.