The Senkaku/Diaoyu Islands Dispute

by Daniel Dzurek (click here to send comments to the author)

18 October 1996

The rekindled sovereignty dispute between Japan and China (includingTaiwan) over the Senkaku/Diaoyu Islands [1] at the eastern edge of the East China Sea involves 500-year-old claims and future offshore oil development. Sovereignty over the islets could affect 40,000 sq km of surrounding continental shelf/EEZ area. The most recent flare-up was ignited when a Japanese ultranationalist group built a makeshift lighthouse on one of the islets, which are controlled by Japan. Diplomatic notes, popular demonstrations, convoys of protest boats, and the death of one protester, who drowned near the islands, have inflamed passions, but done little to shed light on the sovereignty and jurisdictional issues.

There are five small volcanic islands and three rocky outcroppings in the Senkaku/Diaoyu group (see table). They have a total land area of some 7 sq km. Most of the islets are clustered around the largest island, Uotsuri/Diaoyu, which covers roughly 8 hectares and lies 170 km northeast of Taiwan and 410 km west of Okinawa. Two outlying islets, Kobi-sho/Huangwei Yu and Akao-sho/Chiwei Yu, are located 31 km and 108 km from Uotsuri/Diaoyu Island, respectively. None of the islets is inhabited. All the features lie within the 200-m isobath, at the edge of the Asian geologic continental shelf. The 2,270-m-deep Okinawa Trough lies seaward of the Senkaku/Diaoyu Islands, separating them from the nearest undisputed Japanese islands.

Recent events brought the long-simmering dispute to a boil on 14 July 1996, when the Japan Youth Association landed on one of the disputed islets. It built a 5-m high, solar-powered, aluminum lighthouse, and requested that the Japanese Maritime Safety Agency designate it an official navigational signal. In 1988, the group had set up a similar structure on the western shore of Uotsuri/Diaoyu Island to reinforce Japan's sovereignty claim.[2]

Taiwanese and Hong Kong Chinese responded with demonstrations and flotillas of boats, which were intercepted by Japanese vessels. One Hong Kong activist died near the islands on 26 September, when he attempted to swim from the protest boats to an islet. On 7 October protesters briefly landed on Uotsuri/Diaoyu Island and raised the PRC and ROC flags, which were later removed by the Japanese. Diplomatic protests were lodged. Japan claimed that it could not act against the lighthouse because it was built on private land, but Foreign Minister Ikeda met with his Chinese counterpart and told him that Japan had no plans to recognize the lighthouse. Chinese Premier Li warned Japan about provoking China, but all the concerned governments began to caution protesters and call for calm. "Private" negotiations between Tokyo and Taipei to permit Taiwanese fishermen to fish outside the 12-nautical mile territorial sea of the disputes islands failed to progress, but the sides agreed to meet again.[3]

Japan claims that it discovered the Senkaku Islands and incorporated the islands in 1895, when they were terra nullius (unclaimed). It maintains that the incorporation met with no Chinese protest and that the islets were always treated as part of Okinawa and not transferred under the Treaty of Shimonoseki, as China claims. Japan cites development activities in the islands by its nationals from 1897 until World War II and American administration under Article 3 of the 1951 San Francisco Peace Treaty. It views the 1971 Ryukyu (Okinawa) reversion agreement with the United States as validating its sovereignty.[4]

The PRC and ROC claim that Chinese discovered the islands in 1372 and subsequently used them as navigational aids. The islands were incorporated into China's maritime defences in 1556. They also cite usage by Taiwanese fishermen and an 1893 imperial edict of the Dowager Empress that awarded Diaoyu Dao, Huangwei Yu, and Chi[wei] Yu to a Chinese pharmacist who had gathered rare medical herbs on the islands. China contends that the islets were transferred with Taiwan to Japan by the Treaty of Shimonoseki, which ended the 1894-95 Sino-Japanese War, and should have been returned after the Second World War, under provisions of the 1943 Cairo Declaration, 1945 Potsdam Proclamation, and Article 2 of the San Francisco Treaty.[5]

None of the claimants disputes the fact that Japan exercised control of the Senkaku/Diaoyu Islands from 1895 until the Second World War. They differ on whether the islets were free for the taking in 1895, how Japan obtained control in that year, whether the islands were traditionally associated with Taiwan or Okinawa, and what the implications of various peace treaties and the 1971 Ryukyu Reversion Agreement are.

In 1971 Japan and the United States signed an agreement returning the Ryukyu (Okinawan) and Daito Islands to Japanese administration. All of the disputed Senkaku/Diaoyu Islands are within the polygon delimiting the returned islands, the coordinates of which were listed in Agreed Minutes that were appended to the 1971 Japan-US Ryukyu Islands Reversion Agreement.[6] Uotsuri/Diaoyu Island is 33 km within the western limit of the polygon. During Senate ratification of the Reversion Agreement, the United States specified that the agreement did not affect the determination of sovereignty over disputed islands. The US Department of State continues to take no position on the sovereignty of the Senkaku/Diaoyu Islands.[7]

Clearly the US administered the Senkaku/Diaoyu Islands with the Okinawan islands under Article 3 of the 1951 San Francisco Treaty and transferred the islets to Japanese administration in the 1971 Agreement. However, these provisions were not predicated on the transfer of sovereignty. It was in Article 2, not Article 3, of the 1951 San Francisco Treaty that Japan renounced rights to various areas, including Formosa (Taiwan). The Reversion Agreement cited Article 3. Therefore, the US action restored the Senkaku/Diaoyu Islands to the administrative status they held before the war. Although the US agreement with Japan cannot be viewed as changing the true sovereignty of the dispute islets, the American inclusion of the islets in a geographic definition of the Ryukyu Islands clearly supports Japan's contention that these islets were associated with Okinawa.[8]

Other documents which might be relevant lack details that would clarify the islands dispute. The 1895 Treaty of Shimonoseki mentioned the "Island of Formosa together with all Islands appertaining or belonging to the said Island of Formosa." The 1951 Japanese Peace Treaty signed in San Francisco included a renunciation of all Japanese rights, title, and claim to "Formosa and the Pescadores" in Article 2. However, neither the ROC nor the PRC were seated at the San Francisco conference; neither signed the treaty. The 1952 Treaty of Peace between the Republic of China and Japan cited Article 2 of the 1951 San Francisco Treaty. It reiterated that "Japan has renounced all right, title and claim to Taiwan (Formosa) and Penghu (the Pescadores) as well as the Spratly Islands and the Paracel Islands." It also recognized that "all treaties, conventions and agreements concluded before December 9, 1941, between China and Japan have become null and void as a consequence of the war." The 1972 Joint Communique between the People's Republic of China and Japan mentioned that Japan "adheres to its stand of complying with Article 8 of the Potsdam Proclamation." The 1978 Treaty of Peace and Friendship between the PRC and Japan merely confirms their Joint Communique.[9] Perhaps, it is understandable that the Senkaku/Diaoyu Islands were not separately cited in early documents. They are minuscule and have never been inhabited. They had little value until offshore oil exploration began in the 1970s, but one might have expected the issue to be addressed in agreements from that period.

The Senkaku/Diaoyu Islands dispute erupted on the international stage, following a 1968 United Nations Economic Commission for Asia and the Far East report suggesting petroleum deposits under the East China Sea. The law of the sea at that time emphasized natural prolongation in determining continental shelf jurisdiction. Ownership of the Senkaku/Diaoyu Islands would permit Japan to leap over the Okinawa Trough and have secure basepoints from which to claim mainland shelf area. When Taiwan and Japan began offshore leasing, their island sovereignty dispute and related overlapping claims became obvious. In September 1970 protesters planted the Taiwanese flag on one of the disputed islets. The 1971 Ryukyu Reversion Treaty triggered protests by the PRC.[10]

The claimants reached a modus vivendi which shelved the sovereignty issue until recently. There have been occasional flare-ups, such as when the PRC listed the islands in its 1992 territorial sea law, but the sides have foregone some provocative opportunities. Japan did not include the islands in its straight baseline claim. Although the PRC and Japan recently promulgated exclusive economic zones, they avoided explicitly delimiting the zones' outer limits and coupled the new laws with calls for negotiating boundaries in overlapping areas. Now, some actions by individuals and non-governmental organizations threaten to wrest the dispute from governmental control.

International law presents many unanswered questions about the Senkaku/Diaoyu Islands dispute. Can claims of sovereignty based in fourteenth century Asia be judged by norms developed in Europe centuries later? What is the nature of discovery and occupation for uninhabited islands? What is the critical date when the dispute crystallized? Were the Senkaku/Diaoyu Islands part of Taiwan or of Okinawa before 1895? How does one interpret ambiguous treaties? Finally, how will the disputed islands affect maritime jurisdiction. Even if ownership of the islets is settled, can that sovereign claim an EEZ or continental shelf from islands that have never been inhabited and seem to have no economic life. The 1982 UN Convention on the Law of the Sea would appear to say no, but several countries claim extended jurisdiction from such features.


Huangwei YuKuba-shima or Kobi Sho25 58'123 41'
Chiwei YuTaisho-jima or Akao-sho25 55'124 33'
Daioyu DaoUotshuri-shima25 45'123 29'
Beixiao Dao*Kita Kojima25 45'123 33'
Nanxiao Dao*Minami Kojima or Minami-ko-shima25 44'123 34'

Dabeixiao Dao*Okino Kitaiwa*
Dananxiao Dao*Okino Minamiiwa*
Feilai Dao*Tobise*

* The correspondence of these feature names is uncertain. Nanxiao Dao appears to be Minami Kojina and Beixiao Dao seems to be Kita Kojima, judging from the PRC National Atlas (1979). However, the likely Chinese meanings of the names suggests that Dananxiao Dao and Dabeixiao Dao may refer to these respective Japanese place names.

Sources: US Board on Geographic Names, Japan: Preliminary Gazetteer (Washington, DC: Department of the Interior, 1953); Toshio Okuhara, Japanese Annual of International Law 15 (1971): 106; Zhongguo Diminglu [Gazetteer of China] (Beijing: Ditu chubanshe, 1983).



1. Japan calls the islands Sento Shosho or Senkaku Retto. The People's Republic terms them the Diaoyu Tai, and the Republic of China renders the same Chinese characters in a different romanization system as Tiao Yu T'ai. [back]

2. Sankei Shimbun (Tokyo) (17 July 1996), p. 1, translated in FBIS, Daily Report: East Asia (hereafter FBIS, East Asia) (19 July 1996). [back]

3. "Chronology of Events," Kyodo (Tokyo) broadcast in English, 26 September 1996, transcribed in FBIS, East Asia (27 September 1996); "Protester Dies in Defense of Disputed Asian Islands," Washington Post (27 September 1996), p. A32; Yuri Kageyama, "Asian Land Fight Heats Up," AP (Tokyo) 25 September 1996; Kyodo (Tokyo) broadcast in English, 7 October 1996, transcribed in FBIS, East Asia (8 October 1996); "Premier of China Joins Fray," Washington Post (1 October 1996), p. A15; Chiang Ching-ling, "Special Dispatch," Chung-kuo Shih-pao (Taipei) (6 October 1996), p. 2, translated in FBIS, China (10 October 1996). [back]

4. Toshio Okuhara, "The Territorial Sovereignty over the Senkaku Islands and Problems on the Surrounding Continental Shelf," Japanese Annual of International Law 15 (1971): 97-102; Thomas R. Ragland, "A Harbinger: The Senkaku Islands," San Diego Law Review 10 (May 1973: 668-69; J. R. V. Prescott, "Maritime Jurisdiction," in Atlas for Marine Policy in East Asian Seas, edited by Joseph Morgan and Mark J. Valencia (Berkeley: University of California Press, 1992), pp. 31-32. [back]

5. Tao Cheng, "The Sino-Japanese Dispute over the Tiao-yu-tai (Senkaku) Islands and the Law of Territorial Acquisition," Virginia Journal of International Law 14 (1973-74): 248-60; Victor H. Li, "China and off-Shore oil: The Tiao-yü Tai Dispute," Stanford Journal of International Studies 10 (Spring 1975): 151-53; Jiang Kun, "Japan Cannot Claim Sovereignty over Diaoyu Islands by Citing the 'Preemption' Principle," Zongguo Tongxun She (Hong Kong) broadcast 1309 GMT, 12 September 1996, translated in FBIS Daily Report: China (hereafter FBIS, China) (17 September 1996); "China Will Never Yield an Inch of Territory," Wen Wei Po (Hong Kong) (12 September 1996), p. A2, translated in FBIS China (16 September 1996). [back]

6. "The territories defined in paragraph 2 of Article I [of the Reversion Agreement] are the territories under the administration of the United States of America under Article 3 of the Treaty of Peace with Japan, and are, as designated under Civil Administration Proclamation Number 27 of December 25, 1953, all of those islands, islets, atolls and rocks situated in an area bounded by the straight lines connecting the following coordinates in the listed order." The Minutes continue with a table listing the following points: (28N, 12440'E), (24N, 122E), (24N, 133E), (27N, 13150'E), (27N, 12818'E), (28N, 12818'E), and (28N, 12440'E), as found in UN Treaties and other International Agreements vol. 23, pt. 1 (1972): 475. [back]

7. Hearings on the Okinawa Reversion Treaty before the Senate Committee on Foreign Relations, 92nd Congress, 1st Session (1971), p. 11; Tao, p. 251. [back]

8. Li, p. 151. [back]

9. The 1952 Peace Treaty can be found in United Nations Treaty Series 138 (1952): 38-48. The 1972 Joint Communique, 1895, 1951 and 1978 peace treaties are found in Fred L. Israel, ed, Major Peace Treaties of Modern History (New York: Chelsea House). [back]

10. Wei-chin Lee, "Troubles under the Water: Sino- Japanese Conflict of Sovereignty on the Continental Shelf in the East China Sea," Ocean Development and International Law 18 (1987): 586; Li, pp. 143-47. [back]