Where social barriers are sufficiently strong, economic barriers are certain to appear. These can range from protectionist trade policies and increasingly strict immigration controls to religious wars and ethnic cleansing.
在社会壁垒足够强大的地区，经济壁垒必然会出现。这些壁垒包括保护主义贸易政策和日益严格的移民控制，甚至宗教战争和种族清洗。