(NO CONFLICTS DESIRED) Historical and Legal Foundation of Japan's Sovereignty Over Senkaku Islands - Discuss Japan
Discuss Japan > Back Number > Nos.13-15 > (NO CONFLICTS DESIRED) Historical and Legal Foundation of Japan's Sovereignty Over Senkaku Islands
Diplomacy, Nos.13-15  Mar. 3, 2013

(NO CONFLICTS DESIRED) Historical and Legal Foundation of Japan's Sovereignty Over Senkaku Islands

Photo : Ozaki Shigeyoshi

Ozaki Shigeyoshi

Chairman Hiromasa Yonekura of Keidanren (the Japan Business Federation) said in September 2012 that the government should admit the existence of a “territorial dispute” over the Senkaku Islands. In a policy agreement between the Japan Restoration Party and the Sunrise Party for the latest general election, furthermore, they said they would prompt China to take the question of the Senkaku Islands to the International Court of Justice (ICJ).

However, it should be noted that the ICJ is an international tribunal tasked with settling “legal disputes” – but not “political disputes” – between nations. If Japan refers the Senkaku problem to the ICJ, it will mean Japan’s admission of the case as a legal dispute and thus may destabilize the status of the Senkaku Islands as a territory of Japan. By no means are the Senkaku Islands a disputed territory. There is no doubt whatsoever in terms of both historical development and international law that the islands are a territory of Japan.

In other words, the Senkaku issue is not a territorial conflict as defined by international law but a diplomatic and political problem that has arisen due to China’s sudden claim of sovereignty over an area that has been recognized as a territory of Japan. This point can be clarified as follows:

Prior occupation under international law means that a country makes a “terra nullius” — a land belonging to no state — into its territory by validly controlling it before other nations. As prerequisites for prior occupation, (1) a nation’s intention to keep possession of the land in question is explicitly exhibited externally in one way or another, and (2) the nation needs to validly occupy it.

Japan’s Valid Control under International Law

As a series of measures the Japanese government has taken with regard to the Senkaku Islands since January 1895 clear the prerequisites, it is fair to say that Japan has acquired territorial sovereignty over the islands.

For the first prerequisite, the Japanese government made a Cabinet decision (on Jan. 14, 1895) to recognize the Senkaku Islands as belonging to the jurisdiction of Okinawa Prefecture, and a private citizen, authorized on the basis of the decision, engaged in the development of the islands, planted poles and regularly hoisted the national flag there. In addition, Japan undertook a series of sovereign acts for the islands, which implicitly expressed its intention to possess them. With these and other actions, Japan clearly expressed its intention to keep possession of the islands.

For the second prerequisite – valid occupation (or control) – various sovereign acts can be mentioned.

The Meiji government incorporated the Senkaku Islands into state-owned land and allowed a private citizen to exclusively use a land area designated by the state. These actions showed Japan’s valid control of the islands. In addition, Japan registered the islands in the national land ledger, set lot numbers, leased and subsequently sold part of the islands to a private citizen, and mobilized police and military personnel for such activities as rescuing people in maritime accidents.

The series of actions taken by the Japanese government since 1895 in connection with the Senkaku Islands fully cleared the requirements for prior occupation.

But there is another important prerequisite for the establishment of prior occupation, i.e. prior occupation under international law applies to a “terra nullius” belonging to no state.

Based on this point, China and Taiwan began asserting in 1971 that “although the Senkaku Islands were historically China’s territory, Japan unilaterally incorporated them into its territory during the first Sino-Japanese war.” It is incredible that a country claiming a territory of its own was unilaterally incorporated into another country’s domain had left it unattended for 76 years. With its assertion, China is attempting to deny Japan’s prior occupation 76 years later.

Let us briefly examine whether China’s claim of sovereignty is justifiable from a historical viewpoint. To examine the legal status of the Senkaku Islands, it is appropriate to divide their history into the Ming era (1368-1644) and the Qing era (1644-1912). It can then be better understood (1) whether the Senkaku Islands belonged to China during the Ming era and (2), if not, whether they became a territory of China during the Qing era.

Foundation of China’s Territorial Claim

First of all, this examination should be based on the undeniable fact that the island of Taiwan was not a territory of China during the Ming era. It was impossible at that time for the Senkaku Islands, located far away from the island of Taiwan, to have been China’s territory. It is absolutely silly to claim that the Senkaku Islands, a solitary group of islands far off in the ocean, were an enclave of the distant province of Fujian or a territory under the direct control of the central Chinese government.

Let us look at China’s claim that it “discovered” the Senkaku Islands, as defined by international law, during the Ming period. According to China, Chen Kan, dispatched to the Ryukyu Islands as an envoy of the Ming dynasty in 1534, saw the Senkaku Islands from a far distance on the way and registered them under a Chinese name in an official record. This act constitutes a “discovery” as defined in international law, China asserts.

This assertion can be immediately rejected. First of all, the record makes no mention of China’s intention to possess the islands. Chen Kan merely saw the island of Kume-jima and said it “belonged to the Ryukyu Islands.” In fact, Chen Kan sailed near Kume-jima without knowing anything about the islands on the way and recognized for the first time that it belonged to the Ryukyu Islands only after being told so by Ryukyu people. All islands on his route were solitary uninhabited islets in the ocean and were given names only as landmarks for sailing ships.

At that time, Chinese envoys’ voyages totally depended on pilots and skilled seamen dispatched by the Kingdom of Ryukyu. It is highly likely that the names of islands, heard from these seamen, were translated into Chinese.

Ships from the kingdom overwhelmingly outnumbered those from China on the Ryukyu-China route in those days. In the 162 years from 1372, when voyages between the Ryukyu Islands and China started, to 1534, when Chen Kan arrived at the islands, 441 official ships from the Kingdom of Ryukyu sailed on the route to the Senkaku Islands while only 21 official ships from China did so. In addition, ships from the Ryukyu Islands began to sail to China in 1372, while Chen Kan only visited the islands 162 years later. It is fair, therefore, to say that the Kingdom of Ryukyu discovered the islands.

In a book titled “Shiryukyuroku” (1561), Guo Rulin said, “The Seki-sho is an island verging on the Ryukyu region.” In connection with this passage, another of Guo Rulin’s books – “Sekisensanbobunshu” – is said to have a sentence that states, “The Sekibi-sho is an island on the border of the Ryukyu Islands in Ryukyu’s territory and was named so by Ryukyuans.”

Furthermore, maritime defense documents written in the second half of the Ming dynasty, such as the “Chokaizuhen” (1562) and “Nihon Ikkan” (1556), offer no proof that the Senkaku Islands were a territory of China.

Historical documents in the Ming period therefore clarify that the Senkaku Islands did not belong to China at that time.

So now the question is whether the Senkaku Islands became a territory of China during the Qing period. Generally speaking, it is difficult to comply with this view as there are no documents in the Qing period stating that the Senkaku Islands belonged to China. In addition, the fact is that the Qing dynasty neither annexed the Senkaku Islands after declaring its intention to possess them nor put them under its valid control.

The sole possible argument is that the Senkaku Islands, geographically speaking, belonged to Taiwan and automatically became a territory of China when Taiwan was made into a Chinese territory.

As historical evidence for the argument, Han-yi Shaw refers to a passage in the “Nihon Ikkan” which says, “Chogyo-sho is a small island in Shoto.” As the Nihon Ikkan says in a separate part, “Shoto is Shoryukyu which the Japanese call ‘Oekoku’ (Taiwan),” Shoto is evidently the island of Taiwan, Han-yi Shaw argues, concluding that the “Chogyo-sho is a small island in Shoto” means the “Chogyo-sho (Uotsuri-jima) is a small islet belonging to the island of Taiwan.”

This interpretation is a bit of a stretch because “Shoto” is evidently distinct from “Shoto Island,” according to the context of the writing. Taiwan is clearly mentioned as “Shoto Island” or “the island in Shoto.” There is no other way of reading it but as “an island in Shoto.”

“Shoto,” in short, is a marine area and so means the sea of Shoto. Specifically, it is the Pacific region extending from the Japanese archipelago to around Taiwan via the Okinawa archipelago and represents a concept comparable to Daitoyo (central part of the Pacific), Shoseiyo (Indian Ocean) and Taiseiyo (the Atlantic). A big island in the Shoto marine area is Taiwan and a small island in the area is “Shoto-shosho” or “Chogyo-sho.”

It is therefore natural to read the passage as “Chogyo-sho is a small island in the sea of Shoto (Shotoyo).”

When Taiwan did not belong to China and its presence was little known, it is hardly conceivable that such solitary small islands located 170 kilometers east of Taiwan could draw voyagers’ attention to the question of whether or not they belonged to Taiwan.

Based on grammatical interpretation and historical background, it is thus impossible to interpret the Nihon Ikkan’s passage stating “Chogyo-sho is a small island in Shoto” as meaning that “The Senkaku Islands are small islets belonging to Taiwan.”

No Trace of Senkakus as China’s Territory

No historical documents in the Qing period offer direct evidence that “the Senkaku Islands became a territory of China in the Qing era.” It is also difficult to regard passages quoted from them as indirect evidence as they are often ambiguous and highly metaphoric.

Accordingly, there is no confirmation that the Senkaku Islands were recognized as islands belonging to Taiwan by China (as a nation) or in general throughout the Qing era. Documents, maps and nautical charts made by China, the Kingdom of Ryukyu (Japan) and Westerners include much more data indicating that the Senkaku Islands were geographically regarded as part of the Ryukyu Islands in the 19th century.

The conclusion from an analysis of Chinese documents is that the Senkaku Islands had neither been a territory of China throughout the Ming and Qing eras nor seen as islands belonging to Taiwan.

China had voiced no objection whatsoever to – and indeed tolerated – Japan’s possession of the Senkaku Islands for 76 years up until 1970. Although China strongly protested France’s move for prior occupation of the Spratly Islands between 1902 and 1932, it had remained absolutely silent about Japan’s exercise of sovereignty over the Senkaku Islands during this period. China maintained the same stance when Taiwan and Okinawa were separated from Japan after World War II.

These facts clearly testify that China did not regard the Senkaku Islands as part of its territory at all at that time.

There is no doubt about Japan’s sovereignty over the Senkaku Islands. Japan should actively inform the international community of this fact while repeatedly presenting its assertion to China and refuting China’s claim. In addition, Japan needs to reinforce its valid control of the Senkaku Islands.


Translation of an article (pages 12-14) in the January 2013 issue of the monthly magazine WEDGE published by Wedge Inc.

Shigeyoshi Ozaki, born in 1936, graduated from the Faculty of Law at the University of Tokyo and completed the doctoral program at the Graduate School for Law and Politics at the university. After working at the Research and Legislative Reference Bureau at the National Diet Library, Ozaki became a professor at several universities including Niigata University and the University of Tsukuba. He specializes in international law.