但商品、资本和劳动力在主权国家内部完全不受限制的流动需要满足两个条件才能成为可能：国家身份的发展，以及出现有能力在出现不利局面时提供安全的国家机关。
But the completely unrestricted movement of goods, capital, and labor within sovereign states became possible only when two conditions were met: the growth of national identity and the emergence of national authorities able to provide security in the face of adversity.