International Law Doctrines of Possible Relevance to the Taiwan Status Issue
International law doctrines such as irredentism, postliminium, prescription, terra sine domino, terra nullius, uti possidetis, etc., are often used to justify the legitimacy of the Republic of China on Taiwan. An overview of these doctrines is provided as follows.
irredentism: claiming a right to territories belonging to another state on the grounds of common ethnicity and/or prior historical possession, actual or alleged.
Comments: Technically speaking, "irredentism" is a doctrine from the sphere of identity politics, cultural & ethnic studies, and political geography. It is not a legal doctrine per se, and hence carries little or no weight in discussing legal claims on territory.
postliminium: the right by virtue of which persons and things taken by an enemy in war are restored to their former state when coming again under the power of the nation to which they belonged.
Comments: The transfer of the title of territory by treaty is an internationally recognized valid method for transmission and reassignment of "ownership." Regardless of the future outbreak of war between the affected parties, or the military occupation of each other's countries, international law does not recognize any claim to "retroactive reversion of title" to previously ceded territory, and the doctrine of "postliminium" cannot be invoked under such circumstances.
prescription: (1) the process of acquiring title to property by reason of uninterrupted possession of specified duration, (2) acquisition of ownership or other real rights in movables or immovables by continuous, uninterrupted, peaceable, public, and unequivocal possession for a period of time.
Comments: Certain countries with a long history have obtained title to their lands based on "prescription." However, Taiwan was a territorial cession in Article 2b of the San Francisco Peace Treaty (SFPT), hence there must be a clear transfer of territorial title in order to be recognized as valid. The doctrine of "prescription" cannot be invoked under such conditions. This analysis is fully confirmed when we recognize that October 25, 1945, was the beginning of the military occupation of Taiwan, and international law specifies that "military occupation does not transfer sovereignty."
"De facto control" does not constitute ownership as we can clearly see from US military occupation of Iraq and Afghanistan. Such military occupation does not mean that the US has possession of the de jure sovereignty over these lands.
terra sine domino: [spoken of populated territory] "land without master," land with no central government, abandoned territory.
Comments: Taiwan was Japanese territory up until April 28, 1952. There is no basis under international law to say that by 1949 Taiwan had already become "terra sine domino," and was thus subject to casual annexation by any other country such as the ROC.
terra nullius: [spoken of unpopulated territory] uninhabited islands or lands, abandoned lands, etc. which are not being used for the advantage of human beings.
Comments: In late 1945, Taiwan had a population of approximately six million, and could certainly not be claimed under the doctrine of "terra nullius."
uti possidetis: a principle that recognizes a peace treaty between parties as vesting each with the territory and property under its control unless otherwise stipulated. (Latin: uti possidetis, ita possideatis -- "as you possess, so may you continue to possess.")
Comments: This principle is not applicable to a discussion of Taiwan's international legal status after WWII because (1) the Republic of China was not a party to the SFPT, in which Japan ceded Taiwan, (2) October 25, 1945, only marks the beginning of the military occupation of Taiwan, and the Republic of China (founded in 1912) had never held legal possession of "Formosa and the Pescadores" at any time before the coming into effect of the peace treaty. (3) Furthermore, Article 21 of the SFPT clearly stipulates the benefits to which "China" is entitled under the treaty, and "Formosa and the Pescadores" are not included.
popular sovereignty: the doctrine that the state is created by and subject to the will of the people, who are the source of all political power.
Comments: The sovereignty as spoken of in any discussion of the disposition of Taiwan in the post-WWII period is "territorial sovereignty," which is the right of a government to exclusively exercise its powers within a particular territory. As such, "territorial sovereignty" must be based on having "territorial title."
in regard to matters of territorial cession, no instances have been found in the post-Napoleonic period where "the people" (in some anonymous fashion) were deemed to hold the "territorial title" to any areas. Rather, "territorial title" is held by a government. This clarification is very important for discussing the details of Taiwan's international legal position.