Chapter 6 – Customary Law and the ROC on Taiwan

Customary Law and the ROC on Taiwan

Many people claim that the Republic of China is the legal government of Taiwan based on the provisions of the following legal (or quasi-legal) announcements, documents, and/or doctrines.

(1) Abrogation of all treaties, conventions, agreements, and contracts regarding relations between China and Japan (including the Treaty of Shimonoseki) by the ROC government in 1937,

(2) Cairo Declaration of Dec. 1, 1943,

(3) Potsdam Proclamation of July 26, 1945,

(4) Japanese Surrender Documents of Sept. 2, 1945,

(5) Treaty of Taipei (Sino-Japanese Peace Treaty) of Aug. 5, 1952.

A comprehensive overview is offered as follows.

In regard to the 1895 Sino-Japanese Peace Treaty, once the obligations of territorial cession were fulfilled via Article 2, that clause of the treaty itself became inactive. In other words, to the extent that the particular provisions in the 1895 Treaty regarding the cession of Taiwan had been fulfilled by the Qing, any portion of the Treaty which could be nullified as a consequence of the war against Japan which (arguably) began in July 1937, or the abrogation of the 1895 Treaty itself at some date, etc. would have to be limited to those provisions which had not yet been fulfilled in their entirety. The cession provision which had already been carried out was no longer active and therefore could no longer be subjected to nullification or any sort of retro-active cancellation.

With respect to the Cairo Declaration and the Potsdam Proclamation, it is significant to note that in the post-Napoleonic period there is no international precedent to show that a “Declaration” or “Proclamation” has the international force of law to transfer the sovereignty of a geographic area from one government to another. Nor is there any precedent to say that the specifications of Surrender Documents have any such force of law between nations.

In regard to the Treaty of Taipei (which came into force on Aug. 5, 1952), Article 2 of the Treaty merely acknowledged Article 2(b) of the SFPT, stating: “It is recognized that under Article 2” of the SFPT “Japan has renounced all right, title and claim to Taiwan (Formosa) and Penghu (the Pescadores).” Indeed, upon the coming into force of the Treaty of Taipei on Aug. 5, 1952, the SFPT had already been in force over three months, hence Japan was no longer holding the territorial title to Formosa and the Pescadores at that time. Obviously, in August 1952 Japan could not make any specifications regarding the disposition of territory which it no longer possessed.

Territorial Cession is Accomplished by Treaty

Customary international law in the post-1830 period has clearly established that territorial cession is accomplished by treaty. Relevant examples are too numerous to mention. In the history of the United States, for example, all territorial cessions were done via the specifications of a treaty, including the following well-known examples:

Louisiana, 1803

Alaska, 1867

Florida, 1821

Guam, 1899

California, 1848

Puerto Rico, 1899

Gadsden Purchase, 1853

Virgin Islands, 1917


Additional International Law Doctrines

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 2 of the 1895 Treaty of Shimonoseki, and again in Article 2(b) of the 1952 San Francisco Peace Treaty (SFPT).  For a territorial cession in a peace treaty, 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.”

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.

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.

Chapter 5   |   Chapter 7