A Defense of Japanese Sovereignty Over the Senkaku/Diaoyu Islands

Legal analyses on the sovereignty dispute over the Senkaku/ Diaoyu Islands have been unfavorable to Japan. The literature is populated primarily with works by commentators who either argue in favor of the Chinese claim1 or conclude that the applicable law is simply too indeterminate to support either party.2 Analyses supporting the Japanese position are rare and call for further explication. 3 This is a surprising state of affairs, given that Japan has the better argument. This Article explains why. Part I simplifies the sovereignty debate by identifying a number of commonly raised issues that are immaterial as a matter of law. Part II organizes the debate by identifying and evaluating the legal questions that matter: (1) whether the Islands were unoccupied territory when Japan annexed them in 1895, (2) whether Japan ever acquired title under the doctrine of acquisitive prescription, and (3) whether the Allies made a lawful determination in favor of Japanese title after World War II in accordance with the Potsdam Declaration and Instrument of Surrender. Part III explains that Japan likely has sovereignty due to the doctrine of acquisitive prescription, which is no more indeterminate than the doctrine of occupation on which China relies, and which trumps China's original occupation as a later-in-time source of title. Pre-war acquisitive prescription from 1895 to 1937 confirms that the Cairo and Potsdam Declarations did not transfer sovereignty to China and establishes that the 1951 San Francisco Peace Treaty's allocation of sovereignty to Japan was lawful. Post-war acquisitive prescription from 1951 to 1970 forms a second, freestanding basis for the Japanese claim.I. RED HERRING IN THE EAST CHINA SEAAt the center of the dispute over the Senkaku/Diaoyu Islands is the question of sovereignty: to which state do the Islands belong? Because the parties have collected a range of historical evidence, relied upon a variety of treaties and official declarations, and asserted multiple alternative theories of title, the question has an air of complexity. Upon close inspection, however, many of the common arguments are legally irrelevant. This Part simplifies the dispute by identifying and clearing away the clutter of issues that cannot affect title to the Islands.A. The Treaty of ShimonosekiSigned at the conclusion of the First Sino-Japanese War in April 1895, the Treaty of Shimonoseki provided in part that China "cedes to Japan in perpetuity and full sovereignty . . . [t]he island of Formosa, together with all islands appertaining or belonging to the said Island of Formosa."4 The parties disagree on whether this language encompassed the Senkaku/Diaoyu. Under the Japanese view, the language did not, the Treaty is inapplicable, and sovereignty hinges on other issues.5 Under the Chinese view, the Treaty transferred sovereignty over the Islands to Japan, and China reacquired sovereignty through the Treaty's subsequent invalidation.6 To support the latter part of this argument, the Republic of China (ROC or Taiwan) relies upon the ROC-Japan Peace Treaty of 1952 (Treaty of Taipei), in which the parties "recognize[d] that all treaties, conventions and agreements concluded before December 9, 1941, between China and Japan have become null and void as a consequence of [World War II]."7 According to Taiwan, this language invalidated the Treaty of Shimonoseki and in doing so reversed the original cession to Japan.8 The People's Republic of China (PRC) makes a similar argument based on China's 1941 declaration of war, which stated, "all treaties, conventions, agreements, and contracts regarding relations between China and Japan are and remain null and void."9 The PRC further asserts that the Treaty of Shimonoseki was of no effect because Japan achieved its terms through military conquest.10 In short, the Chinese contention is that China gave sovereignty to Japan in the Treaty of Shimonoseki and either Japan gave it back in the Treaty of Taipei, Shimonoseki was invalid to begin with, or China unilaterally nullified the original transfer in 1941. …