The Positions of the United States and the United Kingdom regarding the Senkaku Islands at the time of the Okinawan Reversion


Japan, after its defeat in World War II, signed the Treaty of San Francisco with the prevailing nations, The Allies, and thus transitioned to an international relationship with these countries recognized under peacetime law.[1] Article 3 of the treaty stipulated that the Nansei Shoto[2] south of 29° north latitude, the Nanpo Shoto[3] south of Sofu Gan and Parece Vela and Marcus Island would be placed under the trusteeship of the United States as sole administering authority. After this region was placed under the administration of the United States, Washington D.C. enacted a number of decrees, such as The Law Concerning the Organization of the Gunto Governments, Provisions of the Government of the Ryukyu Islands, and Civil Administration Proclamations. The geographical boundaries of the Ryukyu Islands were delineated by latitude by the United States Civil Administration of the Ryukyu Islands (USCAR), which included the Senkaku Islands within USCAR’s administrational jurisdictions.[4] Japan maintained territorial rights, including the power of disposition (i.e. jus disponendi), and residual sovereignty over these islands, despite the United States’ administering authority.

On August 15, 1945 Japan consented to the Potsdam Declaration – a provision to ending World War II. The Japanese constitution, which is based on the principles outlined in the declaration, was promulgated on November 3, 1946. Article 9 of the Japanese Constitution stipulates that Japan would renounce its right to war, its right to maintain a military force, and its right to belligerency.[5] In other words, Japan was rendered defenseless to foreign invaders as it no longer possessed the ability to muster an organized counteroffensive. Article 5 of the Treaty of San Francisco stipulates that Japan would rely on the United Nations’ right of collective defense for its own self-defense. Article 6(a) mandated that The Allies end their occupation of Japan and withdraw their forces within 90 days after signing the treaty. Simultaneously, this article enabled The Allies to station their forces within Japan through the signing of bilateral or multilateral treaties formed with Japan.

The United States, in order to ensure Japan’s security, signed the Security Treaty Between the United States of America and Japan on the same day that the San Francisco Peace Treaty was signed.[6] As such the United States secured the right for its forces to be stationed within Japan. Additionally, the two countries signed an agreement regarding the status of American forces (i.e. the Status of Forces Agreement) stationed in Japan based on Article 6 of the treaty, in exchange for Japan providing base facilities to the United States.[7] In 1960 the U.S. – Japan Security Treaty and the Status of Forces Agreement (SOFA) were revised and United States forces have been stationed in Japan under these provisions to this day. Later, territories which had been placed under the administration of the United States were gradually returned to Japan. The last of these were the Nansei Islands which are located south of 29° north latitude. After many developments, the United States agreed to return these islands to Japanese control during the 1969 Japan-U.S. Summit.[8] The two countries signed the 1971 Okinawa Reversion Agreement and Okinawa was reverted to Japanese control on May 15, 1972.[9]

The United States and the United Kingdom had to clarify their positions on the Senkaku Islands as they would be returned to Japan with the conclusion of the Okinawa Reversion Agreement. This was done in light of the tense security environment in East Asia generated by both China and Taiwan also laying claim to the islands, thus creating the potential for conflict. This short work endeavors to introduce how the United States and the United Kingdom viewed the Senkaku Islands at the time of the Okinawan Reversion, based upon papers written at the time.

1. China’s sovereignty claim over the Senkaku Islands and the Okinawan Reversion

The Republic of China (hereafter Taiwan) grew interested in the territorial status of Okinawa during the 1950s. Once the return of Okinawa became a topic of consideration, Taipei unofficially courted the United States Department of State to jockey for Okinawa to be handed over to Taiwan rather than to be returned to Japan.[10] The Committee for the Coordination of Joint Prospecting for Mineral Resources in Asian Offshore Areas (CCOP) at the United Nations Economic Commission for Asia and the Far East (ECAFE) conducted a mineral survey from October 12, 1968 to November 29 of that year. The survey, which concerned the East China and Yellow Seas, indicated the potential of oil reserves in these waters.[11] These results gave rise to a conspicuous sovereignty dispute over the Senkaku Islands in the East China Sea.

On July 17, 1970, the Taiwanese Government approved a concession (i.e. a petroleum exploration contract) between China Petroleum Corporation (CPC) and Pacific & Gulf Oil Company. This contract granted the latter prospecting rights to an area of the continental shelf in the East China Sea delineated to fall within 25° to 27° north latitude, and 121° to 125° east longitude.[12] However, Tokyo filed a protest with Taipei given that this area overlapped with the area that the Japanese Government reserved for a Japanese oil developer. Later, Pacific & Gulf Oil as well as Conoco Inc. pulled out of the production framework after Washington D.C. indicated in the mid-1970s that it would not ensure the protection of their interests.[13] Consequently the dispute between Tokyo and Taipei subsided.

It is a well-known fact that the People’s Republic of China (hereafter China) abruptly began its own sovereignty claims over the Senkaku Islands immediately after the CCOP report. China on December 30, 1971 objected to Uotsuri Island and other islands being incorporated within the scope of the territory to be returned within the Okinawa Reversion Agreement. China issued a statement in protest, claiming “This is a gross encroachment upon China’s territorial integrity and sovereignty.”[14] China also claimed the following three points. (1) The islands were already included within China’s defensive zone as early as the Ming Dynasty, as the islands appertain to Taiwan rather than Ryukyu or present-day Okinawa. (2) The boundary between China and Ryukyu in the region is delineated between the islands of Chiwei and Kume. (3) Japan stole these islands during the Sino-Japanese War by pressuring the Qing Dynasty Government to sign the Treaty of Shimonoseki and cede “The Island of Formosa (i.e. Taiwan) together with all Islands appertaining or belonging to the said Island of Formosa” along with the Pescadores Islands. Furthermore, Japan as the aggressor plundered these territories from China, and thus its claims of sovereignty are based on “blatant logic akin to a thief pilfering goods.”

The weakest point in Beijing’s territorial claims over the islands is that it neglected to make its case for sovereignty, not even once, during the 75 year period between Tokyo originally annexing the islands and the announcement of the CCOP report. This is indicative of the fact that the basis for Beijing’s territorial claim is to seek the waters around the islands as well as gaining exclusive control of the natural resources that the Senkakus offer, such as the marine petroleum endowments and sea-floor hydrothermal deposits found in their surrounding waters. Simultaneously, another major goal is Beijing’s desire for the national security benefit of securing a route to the Pacific Ocean for the People’s Liberation Army Navy (PLAN). It has even been reported that Beijing announced in 2013 that the Senkaku Islands were critical national interests and that it would secure the islands even if it required the use of military force.

2. The Senkaku Islands problem and the United States’ position

During Okinawa’s trusteeship, the United States exercised its administrative rights over the Senkakus. When the U.S. made the decision to return Okinawa, which includes the Senkakus, to Japan it needed to determine its position on the islands and thus confront the territorial claims of Taipei and Beijing.[15] This is as a consequence of Article 5 of the Treaty of Mutual Cooperation and Security between the United States of America and Japan (the revised version of the Security Treaty between the United States and Japan which was effectuated in 1960 as aforementioned) which states that in the case of an armed attack against either party in territories under Japanese administration, both parties would cooperate to address the threat. In other words, if China were to carry out a military assault on the Senkaku Islands, the United States, in accordance to its own constitutional proceedings, would respond to the attack along with Japan.

The United States drafted secret documents summarizing five points which defined its stance on the Senkaku Islands, noting that other parties such as Beijing and Taipei had also requested that the Ryukyu Islands not be returned to Japan.[16]

Firstly, these papers clarified Washington’s position towards the Okinawan reversion.[17] U.S. and Japanese maps from World War II both indicate the Senkakus as appertaining to Okinawa prefecture and being governed by Japan. These maps prove that the Senkakus were included in the territories that were taken over by the United States in accordance with Article 3 of the Treaty of San Francisco. Therefore, returning these territories would not infringe upon the U.S.’s basic stance of not getting bogged down in sovereignty disputes.

The document also mentions Beijing’s mistrust of Washington’s position on the Senkakus.[18] They note that although China takes a somewhat softer stance on two of the Senkakus which act as live-fire training grounds for the United States military, as maintained by the Okinawa Reversion Agreement, Beijing criticizes Washington’s position as pro-Japan. Moreover, these documents indicate that China cites the agreement in itself as proof of its assertion that the United States’ position lacks neutrality.

The document’s third point touches upon America’s neutrality in relation to Article 5 of the 1960 U.S. – Japan Security Treaty.[19] Article 5 states, “Each Party recognizes that an armed attack against either Party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger…” The papers mention that some Japanese argue that applying Article 5 to defend the Senkakus from Chinese incursion would not fall in line with the United States’ official position of neutrality given that it has officially acknowledged that it would return the sovereignty of Okinawa, which includes the Senkaku Islands, to Japan. It was also mentioned that the Japanese Government, as well as media outlets, had for some time intentionally avoided broaching the topic of the extraordinary circumstances surrounding the Senkaku Islands problem, despite being fully aware that the scenario posed a glaring inconsistency with Washington’s fundamental position. Therefore, it is conceivable that the United States, fully aware of this predicament, must have anticipated that Article 5 would become the focus of attention if the Senkaku problem worsened between Japan and China – especially if oil reserves were to be found.

The papers noted American oil companies operating in Japanese waters as a concern.[20] Several of the drill sites in which American oil companies were licensed to operate by both the South Korean and Taiwanese governments overlapped with areas over which Japan claimed sovereignty. The waters surrounding the Senkaku islands, which were licensed to Pacific & Gulf Oil Company, were particularly concerning as they could cause friction with the Chinese Nationalist Party or the mainland Chinese Communist Party. The United States Government issued a warning to all American oil companies and spoke with each interested government, explaining that the United States has no interest in becoming a party to the territorial disputes surrounding the North Asian continental shelf. In this manner, Washington concluded that it would be able to avoid direct involvement in the matter for the time being.

3. The United Kingdom’s view of the Senkaku Islands

The People’s Republic of China (PRC) proclaimed its founding on October 1 of 1949. The Soviet Union promptly recognized China the following day, followed by Bulgaria on October 3, Burma on December 6, and India on December 30, 1949. The United Kingdom, which had recognized Taiwan, was the first Western country to recognize China on January 6, 1950. The U.K., despite recognizing the Beijing government, became the first country to continue its working relationship with Taipei, establishing a de facto diplomatic mission through which it maintained its trade and consular ties.[21]

The U.K., a World War II victor, was not adamantly involved in Asia’s post-war policies, focusing rather on European affairs. Nevertheless, the British Government drafted a secret memorandum reassessing the circumstances of the Senkaku Islands, as the islets could become the center of a dispute between Japan, Taiwan, and China if the United States were to return its administrational rights to Japan under Article 3 of the San Francisco Peace Treaty.[22]

The memorandum offers a comprehensive summary of the history and legal status of the islands. Moreover it acknowledges the fact that China began disputing Japan’s title to the Senkakus on December 29, 1970 (Taiwan began disputing Japan’s title in the early 1970s) after the possibility that the nearby continental shelf may be home to oil reserves had arisen.[23] The document elucidated the British stance on the Senkaku Islands, raising the following seven points: (1) the geographical circumstances of the islets, (2) the U.K.’s initial understanding of the Senkakus, (3) the standing of the Ryukyu Islands, (4) the relationship between the Ryukyu and Senkaku islands, (5) the history of the Senkaku Islands from 1896 to 1945, (6) the history of the islands from 1945, and (7) sovereignty claims over the islands as well as counterarguments.[24]

The memorandum opens by noting the geographical aspects of the Senkaku Islands with maps.[25] It acknowledges that the Senkakus are a group of uninhabited islands sporadically located in the East China Sea at 124° east longitude and 25°55’ north latitude.[26] The islands are located 150 nautical miles (NM) from Ishigaki Island and 100NM from Taiwain’s Keelung City. They are separated from the Ryukyu Islands by the Okinawa Trough, a maritime trench that is 500NM wide and 2000m deep. A portion of the Senkaku Islands are clearly indicated on maps published in London between 1794 and 1832. British Royal Navy sea-charts from 1876 – later amended in 1881 – of the East China Sea (Map No. 1262) also indicate the islands. The maps do not cite the ownership of the islands, but at the very least suggest the Chinese knew of the islands at the end of the 18th century.[27]

The memorandum discusses the status of the Ryukyu Islands,[28] citing official documents from the British Government, as well as the relationship between the Ryukyu and Senkaku islands.[29] The history of the Ryukyu Islands was also covered; the islands were recognized from the beginning of the 17th century as a quasi-independent state that paid tribute to both the Chinese Emperor and the rulers of the Satsuma Domain in Japan. The denizens of the Ryukyu Islands were recognized as members of the Japanese race who spoke a dialect of Japanese. However, these denizens also adopted rituals, practices, and an ephemeris from China. China opposed Japan’s annexation of the Ryukus in 1879, bringing conflict to the forefront. Former United States President Ulysses S. Grant, who was touring the Far East at the time, urged Japan and Qing China to discuss a proposal for the partition of the Sakishima Islands through an arbitration committee. The two sides discussed the proposition in the summer of 1880, but to no avail. British Government documents noted that peace talks after the First Sino-Japanese War as well as the 1895 Treaty of Shimonoseki, which ceded control of Taiwan to Japan, made no mention of the Senkaku Islands.

As for the relationship between the Ryukyu and Senkaku islands, it is unclear as to whether the latter were mentioned during the negotiations over the former which ensued between 1879 and 1880. Thus, Japan had not asserted that the Senkaku Islands were included within the Ryukyus as of 1894 at the latest. The Japanese Government first expressed interest in the Senkakus after a tea merchant named Koga Tatsushiro discovered them in 1884. The islands were incorporated into Okinawa Prefecture in 1895 and placed under the administrative jurisdiction of Ishigaki – a town located in the Yaeyama District of that prefecture. There are no documents held by the British Government indicating that the Senkakus were discussed during these negotiations. Furthermore, the Treaty of Shimonoseki does not list Taiwan’s appertaining islands. It is probable that Japan became interested in the Senkaku Islands after acquiring Taiwan.

The memorandum next discusses the history of the Senkakus harking back to Japan’s occupation of the islands in 1896 to Tokyo’s defeat in 1945,[30] as well as the post-war period from 1945.[31] The document cites articles published by the Japanese press which indicate that a group of Japanese settlers made landfall on the islands sometime during 1897 or 1898. A Japanese survey mission designated the moniker of ‘Senkaku’ in 1900. The documents also indicate that a member of the island chain was given to a Japanese citizen residing in Okinawa during the 1920s. However, this island has hitherto remained uninhabited. Maps of Japan drafted by the British War Office in 1923 explicitly label the territory as the Senkaku Islands. After 1945 the Senkaku Islands were governed by USCAR as part of the Ryukyu Islands. The memorandum determines that there is no evidence of China protesting American governance of the Senkakus.

Lastly, the memorandum mentions articles published around 1971 in Chinese newspapers and magazines, summarizing the various sovereignty claims as well as counterarguments repeatedly made between Japan, China, and Taiwan.[32] The dispute between Tokyo and Taipei stems from the latter granting development rights to the Pacific & Gulf Oil Company for a maritime mining site. Tokyo argued that Taipei had no legal basis for granting these rights. Taipei introduced a counterargument asserting that the waters in question are historically, geographically, and traditionally part of Taiwan’s continental shelf, given that Taiwan had ratified the Convention on the Continental Shelf in August of 1970. Meanwhile, Beijing claimed the Senkakus as Chinese territory on December 29 of 1970 in its People’s Daily, citing ‘ancient evidence’ without providing any evidence whatsoever. Beijing claims that the islands appertain to its Taiwan Province.

The memorandum raises the fact that in April of 1971 the United States had not intervened in the dispute over the Senkakus between Tokyo and Beijing. It also notes that the islands, at the time, were governed by the United States as part of the Ryukyu Islands. Moreover, it notes that China claims all the ocean-floor and subterranean resources surrounding the Senkakus, in addition to those resting in neritic waters contiguous to China. The British document concludes that for the time being, Beijing contends that continental shelves should be delineated through negotiation, but would likely enter negotiations arguing that the Senkaku Islands were clearly Chinese territory.


This report documents how the United States, a party to the Okinawa Reversion Agreement, has resolutely maintained its principal position in regards to the Senkaku Islands. Moreover, this position has been upheld even in the face of complications involving Article 5 of the U.S. – Japan Security Treaty. China, unlike at the time of the Okinawan reversion, is now an economic power which has dramatically strengthened its military capabilities and no longer obscures its ambitions of sovereignty over the Senkakus. Some U.S. leaders have publicly announced that America would maintain its policy of non-interventionism by suggesting that the U.S.—Japan Security Treaty would not automatically be applied even if Beijing were to stage a military attack on the Senkakus.[33] These statements were made in an attempt to improve relations with and to avoid confrontation with China. Afterwards, however, Washington D.C. declared that the Senkakus are included within the territories under Japanese administration as stipulated within Article 5 of the U.S. – Japan Security Treaty, and that the U.S. as well as Japan would cooperate to address a military attack from China.

Meanwhile, the memorandum drafted by the United Kingdom – another World War II victor – upholds neutrality. The memorandum achieves this by carefully exploring the geographic and historic circumstances of the Senkakus using documents procurable at the time of the Okinawan Reversion, while offering a juxtaposition of the respective sovereignty claims made by Japan, Taiwan, and China. It is intriguing that the memorandum takes note that Beijing first claimed sovereignty over the Senkakus shortly after the CCOP report which indicated the possibility of maritime oil resources. Furthermore, the memorandum points out that China has neglected to provide any documentation supporting its claims other than ancient texts.

Scope of the Okinawa Reversion Agreement

The territories outlined above indicate the scope of the 1972 Okinawa Reversion Agreement. All islands that fall within the outline above, including the Senkaku Islands, were returned to Japan.

English map: (; as of August 9, 2020)

  1. Even though the USSR was a member of The Allies, it refused to sign the Treaty of San Francisco (signed on Sept. 8, 1951 and effectuated on Apr. 28, 1952 by 46 signatories) due to its dissatisfaction with Article 2(c) — the portion that stipulated that Japan would renounce all of its claims to the Kuril Islands and Southern Sakhalin. Tokyo and Moscow would sign the Soviet-Japanese Joint Declaration on Oct. 19, 1956 (effectuated on Dec. 12, 1956), concluding the state of war between both countries. Both countries enjoy a provisional relationship under international peacetime law. Ultimately, the two sides must form a peace treaty.
  2. The scope encompassed the Ryukyu and Daito islands.
  3. The scope encompassed the Ogasawara Islands, Nishinoshima Island and the Volcano Islands.
  4. The Ministry of Foreign Affairs of Japan, Bureau of Information and Culture, 『尖閣諸島について』, 1972, p.7.
  5. Article 9 of the Japanese constitution stipulates: “(1) Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes. (2) In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.”
  6. Article 1 of the Security Treaty Between the United States of America and Japan (signed on Sept. 8, 1951 and effectuated on Apr. 28, 1952).
  7. “Agreement under Article 6 of the Treaty of Mutual Cooperation and Security between Japan and the United States of America, Regarding Facilities and Areas and the Status of United States Armed Forces in Japan"
  8. After receiving Tokyo’s position paper, the United States Government drafted in May of 1969 the National Security Decision Memorandum 13 (NNDM13) ‘Policy Toward Japan.’ Details of the provisions requested by the U.S. Government to that of Japan regarding policy on post-reversion Okinawa during the negotiations thereof are outlined within「沖縄返還交渉と韓国・台湾」 by S. Hatano, and the Ministry of Foreign Affairs of Japan 『外交資料館報』(Diplomatic Archives Gazette) No.27 (Dec. 2013).
  9. Agreement between Japan and the United States of America Concerning the Ryukyu Islands and the Daito Islands (signed on Jun. 17, 1971 and effectuated on May 15, 1972).
  10. Op.cit. 9, p.28.
  11. Emery et al, Geological Structure and Some Water Characteristics of the East China Sea and Yellow Sea, in Economic Commission for Asia and the Far East, Committee for Co-Ordination of Joint Prospecting for Mineral Resources in Asian Offshore Areas (C.C.O.P) Technical Bulletin, vol. 2. 1969., (as of Sept. 10, 2016)
  12. T. Okuhara 「尖閣列島と領有権問題④」,『サンデー沖縄』(Jul. 29, 1972).
  13. Fillmore C. F. Earney, Marine Mineral Resources (Routledge, reprinted 1990), p. 40. (as of 19 September, 2016)
  14. “Ministry of Foreign Affairs of the People’s Republic of China Statement” issued on Dec. 30, 1971, 『人民中国』 (People’s China) 2012 special issue, p.30.
  15. Okinawa, as stipulated by Article 3 of the Treaty of San Francisco, could have been placed under the trusteeship of the United Nations if the United States had proposed to do so. However, the United States chose to return Okinawa to Japan.
  16. Department of State Briefing Paper Senkakus, (Secret, United States Department of State, August 1972) — ‘declassified’ (Authority NND977508) on Apr. 13, 1978.
  17. Ibid., para. 2.
  18. Ibid., para. 3.
  19. Ibid., para. 4.
  20. Ibid., para. 5.
  21. A. Takeshige 「台湾の外交断絶国との実務経験ー1950年初頭の英国との例を中心ー」,『日本台湾関係報』No. 9 (May 2007), p.15. (as of September 19, 2016)
  22. Foreign and Commonwealth Office, Research Department Memorandum, The Senkaku Island, Department Series No 10. (File No. RR 2/10 Restricted), (12 August, 1971), (Closed until 2002).
  23. Ibid., para. 1, p. 1.
  24. Ibid., p. 2.
  25. Ibid., para. 2, p. 3.
  26. Ibid., para. 3, p. 4.
  27. The Qianlong Emperor of the Qing Dynasty ruled continental China at the end of the 18th century. The People’s Republic of China did not exist at this time.
  28. Ibid., paras. 4-5, p. 5.
  29. Ibid., paras. 6-8, pp. 6-7.
  30. Ibid., para. 9, p. 7.
  31. Ibid., paras. 10-11, p. 7-8.
  32. Ibid., paras. 12-18, pp. 8-11.
  33. For instance former United States Vice President Walter F. Mondale (Carter Administration, Jan. 1977 to Jan. 1981) while serving as the U.S. Ambassador to Japan (1993 to Dec. 1996) suggested in an interview that was quoted in the New York Times on October 20, 1996 that “the seizure of the [Senkaku] islands would not automatically set off the security treaty and force American military intervention." This comment was the cause of much uproar. Article details: Nicholas D. Kristof, Would You Fight for These Islands?, The New York Times, 20 October, 1996. (as of October. 2, 2016)

TAKAI Susumu
(The Sasakawa Peace Foundation — Senior Research Fellow)

TAKAI Susumu completed his coursework for the Doctoral Program at Aoyama Gakuin University Graduate School of Law in 1974. Afterwards he served as an assistant researcher at the Japanese Defense Agency (presently the Ministry of Defense), National Institute for Defense Studies (NIDS) as well as acting as head at the Research Department and Head Librarian until 2006. While at NIDS he studied at the King’s College London, researching “International Law of Armed Conflict” and “Legal Aspects of Defense Studies. Later, Mr Takai served as a lecturer at Aoyama Gakuin University’s Faculty of Law and School of International Politics, Economics and Communication. During this time he concurrently lectured at Aoyama Gakuin University’s Graduate School, specializing in international law. He currently serves as Director Emeritus of the Japan Society of Defense Law, President of the Security Strategy Research Institute of Japan, Administrative Director at the Japan Forum for Strategic Studies, Senior Research Fellow at The Sasakawa Peace Foundation — Center for Islands Studies, Member of the Japanese Cabinet Secretariat’s ‘Advisory Panel on Communications Concerning Territorial Integrity.’ Mr Takai also works as an instructor, teaching international law at Tokyo City University. His major published works include 『国連安全保障法序説』(内外出版) — (‘An Introduction to United Nations Security Law’ — Naigai publishing), 『国連と安全保障の国際法』— (‘The United Nations and Security in the Eyes of International Law’ — Naigai Publishing), and 『パワーポイント国際法』(内外出版) — (Power Point International Law — Naigai Publishing). Mr. Takai has also written numerous works spanning such topics as United Nations security law, international maritime law, and international aero-space law.