Border
Open borders

An open border is the deregulation and or lack of regulation on the movement of persons between nations and jurisdictions. This definition does not apply to trade or movement between privately owned land areas. Most nations have open borders for travel within their nation of travel, though more authoritarian states may limit the freedom of internal movement of its citizens, as for example in the former USSR. However, only a handful of nations have deregulated open borders with other nations, an example of this being European countries under the Schengen Agreement or the open Belarus-Russia border. Open borders used to be very common amongst all nations, however this became less common after the First World War, which led to the regulation of open borders, making them less common and no longer feasible for most industrialized nations.
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