Despite the Soviet annexation, Japan continues to claim the southernmost islands as the Northern Territories, consisting of Iturup, Kunashir, Shikotan, and the Habomai Islands.[1] This claim is based on ambiguities in several documents and declarations made during and in the aftermath of World War II. The Yalta Agreement, signed by the United States, United Kingdom, and Soviet Union in February 1945, stated that in return for declaring war on Japan, the Soviet Union would receive several territories, including the Kuril Islands.[2] However, the later Potsdam Declaration, which provided for Japan's unconditional surrender, did not mention the Kurils, instead referring to the 1943 Cairo Declaration by the US, UK, and China.[3] The subsequent Treaty of San Francisco forced Japan to give up their claims to the Kuril Islands, but since the Soviet Union refused to sign the treaty, the US still considers the Kurils as Japanese territory under Russian control.[4] In addition, Japan claims that the Northern Territories are not a part of the Kuril Islands and had officially been a part of Japan from the Treaty of Shimoda until the end of World War II, and thus should be counted as Japanese territory under the Potsdam Declaration.[1][5] In response, Russia claims that the Yalta Agreement explicitly allowed for the annexation of the entire archipelago.[6] Japan claims that the Yalta Agreement is a secret agreement between the United States, Britain, and the Soviet Union, and that Japan, which is not a party to the agreement, will not be bound. In addition, the Japanese government claims that the ownership of the Kuril Islands and South Sakhalin, which the Japanese government has abandoned, is not specified in the San Francisco Peace Treaty, and the Soviet Union has not signed the treaty, so it is undetermined under international law.
The dispute over the Kuril Islands was one of the main reasons that the Soviets did not sign the Treaty of San Francisco, and the state of war between the two nations persisted until the Soviet–Japanese Joint Declaration of 1956, in which Japan agreed to renounce their claims to Iturup and Kunashir in return for the Soviets returning Shikotan and the Habomai Islands. However, due to American intervention, the negotiations that led to the joint declaration were unable to resolve the dispute, and to date, no formal peace treaty has been signed between Japan and Russia, the Soviet Union's successor state.[1][6] The offer of splitting the disputed territories has been repeated by the Russian government, and leaders of the two countries have met several times to discuss a solution to the dispute.
Okinotorishima is an uninhabited atoll in the Philippine Sea. Discovered by European explorers[who?], Okinotorishima went unclaimed until the Japanese arrived in the territory in 1931, with the atoll becoming the southernmost point in Japan.[7] Japan claims that Okinotorishima is an islet, and accordingly claims a large exclusive economic zone (EEZ) around the island under the United Nations Convention on the Law of the Sea (UNCLOS). However, this classification has been contested by China, Taiwan, and South Korea, who contend that Okinotorishima does not meet UNCLOS's criteria for an islet of being able to support human habitation, and thus that Japan cannot claim an EEZ around the strategically located atoll.[7][8] To maintain their claims, Japan has spent over US$600 million to build observation posts and shore up the atoll against erosion and typhoon damage, and has also cultivated coral in the area in an attempt to slowly grow reefs into islands.[9]
Neither the PRC nor the ROC disputed the Japanese and American rule over the Senkaku Islands until the early 1970s, possibly due to the discovery of potential oil reserves in the area in 1968.[11] Both Chinese claims are based on knowledge of and control over the islands prior to their Japanese discovery in 1884 and their acquisition by Japan during the First Sino-Japanese War, which ultimately resulted in the ceding of nearby Formosa and surrounding islands to Japan in the Treaty of Shimonoseki; the Chinese claims include the Senkaku Islands in this transaction, and thus also include them in the Treaty of San Francisco at the end of World War II, which returned Taiwan to China.[11] The Japanese and Americans dispute these claims, stating that there was no evidence of a Chinese presence on the islands when the Japanese claimed them in 1895, and that they had been included in the administration of the Ryukyu Islands after World War II with no objections by either Chinese government.[11] The Senkaku Islands have seen many incidents between the three countries at the center of the dispute since the 1990s.
Japan has protested the South Korean presence on the Liancourt Rocks, claiming that they were not included in the territory that Japan surrendered in the Treaty of San Francisco. Both the Japanese and Korean claims to the islands rely on historical documents which indicate activity by each side in the area; the Koreans claim that historical places such as Usan Guk (conquered by the Silla in 512), Usando, and other islands owned at various times by Korean kingdoms are the Liancourt Rocks, while the Japanese attribute these mentions to other islands such as Jukdo or Ulleungdo and instead point to records indicating Japanese fishing activity around the islands from, at the latest, 1667.[12]
^Szalontai, Balázs (2013). "Instrumental Nationalism? The Dokdo Problem Through the Lens of North Korean Propaganda and Diplomacy". Journal of Northeast Asian History. 10 (2).
