In September 1931, Japan began its expansion in Asia and sent its troops into northern China. By 1939, the Japanese armed forces had occupied a vast area of central and eastern China. In December 1941, the R.O.C. government declared war against Japan, and at the same time issued a proclamation abrogating all treaties with Japan, including the Treaty of Shimonoseki on the ground that the Treaty was "unequal."

The Treaty of Shimonoseki, however, is a territorial treaty. A unilateral proclamation to abrogate a treaty by a party to the treaty may be valid with respect to a treaty of executory nature, but it cannot effectively abrogate a territorial treaty. This is true even though the defeated State regards the treaty as unequal. A treaty in which a defeated State is forced to cede a territory is necessarily unequal because the defeated State is not in an equal bargaining position with the victorious State. The defeated State cedes the territory to end the war and save the State. The term "unequal treaty" is a political concept rather than a legal term recognized in international law. (FN: 54) No such treaty has ever been effectively abrogated or revoked on the ground of inequality in history. It follows that the proclamation of the Chinese government abrogating all treaties with Japan was ineffective with respect to the Treaty of Shimonoseki.

(54) For a discussion of unequal treaties, see GARY L. SCOTT, CHINESE TREATIES: THE POST-REVOLUTIONARY RESTORATION OF INTERNATIONAL LAW AND ORDER 85-99 (1975). "[N]one of these writers[, Grotius, Pufendorf, Vattel, and Wolf,] considered that inequality in treaties was in any way a cause for abrogation or a factor invalidating treaties." Id. at 86. See generally PETER WESLEY-SMITH, UNEQUAL TREATY 1898-1997; CHINA, GREAT BRITAIN AND HONG KONG'S NEW TERRITORIES (1998); FARIBORZ NOZARI, UNEQUAL TREATIES IN INTERNATIONAL LAW (1971).

Furthermore, a territorial treaty cannot be abrogated or revoked on the ground of a subsequent aggression of the other party to the treaty. In 1955, during the period of parliamentary debates on the sovereignty over Formosa in the British House of Commons, legal scholar Georg Schwarzenberger commented on the cession of Formosa by China to Japan in the Peace Treaty of Shimonoseki:

China had ceded Formosa to Japan by the Peace Treaty of Shimonoseki of April 16, 1895. In order to judge the validity of this cession [the] subsequent developments in international law which may, or may not, have affected the validity of cessions achieved as the result of aggressive war must be disregarded. Thus, the validity of this cession can hardly be contested.

In general, the P.R.C. government claims the island of Taiwan on three grounds: historical ownership, abrogation of the Treaty of Shimonoseki, and the Cairo Declaration. None of these grounds are valid in international law.

The first ground is historical ownership. It claims that the island of Taiwan was originally owned by China, and therefore, is now China's territory. There is no rule in international law which lends support to such a claim. Regardless of the length of time during which China's governments had effective control of the island of Taiwan, international law does not recognize a claim of a territorial title based on the historical ownership. If such a ground were valid for a claim of a territory, it would nullify all treaties in which territories were ceded.

The second ground that the P.R.C. government uses to claim the island of Taiwan is that the Treaty of Shimonoseki was abrogated. The P.R.C. government claims that the R.O.C. government abrogated the "unequal" Treaty of Shimonoseki by a proclamation when "Japan launched an all-out war of aggression against China" in 1941. As explained earlier, such a proclamation to abrogate the Treaty is not valid, (FN: 189) and a succeeding government cannot claim what its predecessor could not do. Furthermore, after a territorial treaty is concluded, a subsequent aggressive act of a party to the treaty, Japan, does not affect the validity of the treaty.

(189) See SCOTT, supra note 54.

The third ground which the P.R.C. government claims as a basis for ownership of the island of Taiwan is the Cairo Declaration . . . . .