Ideology and culture matter, and may be decisive in the battle for the euro.

Over many months, a mighty army has advanced on the citadel of the European currency with the cry: “It will never work!” The army was quick and single-minded, the citadel slow and divided. The besiegers were thousands, steeled by convictions all the more fervent for their extreme simplicity. Their reasoning was as follows: the euro area is not a political union and can never become one, because Europeans have no appetite for it and nation-states will not relinquish power. The citadel, therefore, is doomed to capitulate and its stubborn resistance merely serves to create profit opportunities for astute traders.

Equally strong and simple was the credo of the defenders, who countered: “It can work!” For years, Europe's heads of government and central bankers had preached that a currency without a state is a smart invention that can last forever. It accomplishes the miracle of removing monetary and trade tensions, while allowing the nation-state to remain the unique master. The Maastricht treaty of 1992 was the final step in the construction of the European edifice. No other transfer of sovereignty will, nor needs to, occur. The European Union can do without the ordinary fiscal, financial and monetary instruments that all textbooks prescribe.