Jules Davids and
Jonathan M. Nielson
A vital function of American diplomacy is the protection of persons, property, and trade interests of U.S. citizens, both native-born and naturalized, in foreign countries. Such protection is commonly referred to as "extraterritoriality." However, extraterritoriality was also applied within the United States in regions claimed by or ceded to sovereign Indian nations. For example, beginning in the 1830s in Indian Territory (Oklahoma), Indians charged with offenses on white land and whites charged with offenses on Indian land within the territory were compelled to stand trial in white courts in Missouri. Extraterritoriality embodies a regime of protections, immunities, and exemptions, claimed on behalf of citizens of one nation living abroad, from the legal system and territorial jurisdiction of the state in which they are resident. Such immunities may be limited, that is, they are restricted to a specific territory or region. Or they may be unlimited or nonspecific, that is, global in their application. Guaranteeing such protection, especially in Islamic and Asian countries, resulted in the eventual development of a system of extraterritoriality which the United States established through negotiation or unilateral imposition in fifteen nations: Algeria (Algiers), Borneo, China, Egypt, Iran (Persia), Japan, Korea, Libya (Tripoli), Madagascar, Morocco, Samoa, Tanzania (Zanzibar/Muscat), Thailand (Siam), Tunisia (Tunis), and Turkey (Ottoman Porte).
In establishing such a regime of diplomatic relationships, the United States drew upon established theoretical principles and historical antecedents. The principle and practice of extraterritoriality is fundamentally a state's de jure claim of sovereignty and a de facto expression of its diplomacy and foreign policy. Most authorities would accept the broad view that sovereignty is a system of order and relationships among states that is based on a "mutual recognition of one another's right to exercise exclusive political authority within its territorial limits." Whereas sovereignty involves a state's claim of jurisdiction over citizens within its borders, extraterritoriality extends those claims beyond them.
See also AMBASSADORS, EXECUTIVE AGENTS, AND SPECIAL REPRESENTATIVES; INTERNATIONAL LAW; PROTECTION OF AMERICAN CITIZENS ABROAD.