As financial markets slide toward disaster, scarcely pausing to celebrate the “success” of the Greek election or the deal to recapitalize Spanish banks, the euro project is finally revealing its fatal flaw. One country poses an existential threat to Europe ? and it is not Greece, Italy or Spain. Every serious proposal to resolve the euro crisis since 2009???haircuts for bank bondholders, more realistic fiscal consolidation targets, jointly guaranteed eurobonds, a pan-European bailout fund, quantitative easing by the European Central Bank ??has been vetoed by Germany, and this pattern looks likely to be repeated next week.

Nobody should be surprised that Germany has become the greatest threat to Europe. After all, this has happened twice before since 1914. To state this unmentionable fact is not to impugn Germans with original sin, but merely to note Germany’s unusual geopolitical situation. Germany is too big and powerful to coexist comfortably with its European neighbors in any political structure ruled purely by national interests. Yet it isn’t big and powerful enough to dominate its neighbors decisively, as the U.S. dominates North America or China will dominate the Far East.

Wise German politicians recognized this inherent instability after 1945 and abandoned the realpolitik of national interest in favor of the idealism of European unification. Instead of trying to create a “German Europe” the new national goal was to build a “European Germany.” Unfortunately, this lesson seems to have been forgotten by Angela Merkel. Whatever the intellectual arguments for or against German-imposed austerity or the German-designed fiscal compact, there can be no dispute about their political import. Merkel’s stated goal is now to create a “German Europe,” with every nation living, working and running its government according to German rules.

Merkel doubtless believes that she is helping Europe when she maternally instructs the Greeks, Italians and Spaniards to “do their homework” and so become good little Germans. But like its less benign predecessors, this effort to impose German hegemony is guaranteed to fail. Europe’s leaders must therefore start considering a previously unmentionable question, perhaps as soon as next week’s summit, if the euro crisis intensifies. This question is not whether Europe will agree to live under German leadership, but whether Germany will agree to live under EU leadership ? or whether the other nations must form a united front against Germany to prevent the destruction of Europe, as they have repeatedly in the past.

To be specific, the euro’s only chance of survival now depends on a decisive move toward political and fiscal union. Angela Merkel plays lip service to such political union, even claiming that democratic accountability is her main condition for financial rescues; but what she means is accountability to German voters, German newspapers and German constitutional judges. She promises to “ do whatever it takes to save the euro ” but vetoes anything that might actually work, claiming deference to German public opinion or national interests.