Most nation-states maintain national currencies, and must therefore pursue fiscal and economic policies that support a monetary union. As the eurozone crisis has starkly reminded us, decentralization cannot extend too far into the budgetary sphere, lest it threaten the common currency’s survival.
当然，国防和外交政策将依然由第二个层面（民族国家）来决定。大多数民族国家都保有本国货币，并因此必须寻求能维护一个货币联盟的一系列财政和经济政策。但欧元区危机也明确提醒我们，权力下放不能过度延伸到预算领域，不然就会影响到共同货币的生存。