As the eurozone experience proves, sustaining a monetary union requires banking, fiscal, and full economic union. And, once members give up their sovereignty over fiscal, banking, and economic affairs, they may eventually need a partial political union to ensure democratic legitimacy.
欧元区的经验表明，维持一个货币联盟需要银行、财政和完全的经济联盟。而一旦成员国放弃了财政、银行和经济事务上的主权，就有可能最终需要一个局部政治联盟保证民主合法性。