Japan Data

Senkaku Power Game: An Overview of the Japan-China Islands Dispute


In September 2012, Japan’s nationalization of the Senkaku Islands brought a flare-up to a simmering dispute with China over who owns the territory. As a result, the November 2014 bilateral summit in Beijing was the first between the countries’ leaders for over two years. This article summarizes the complex history of the islands and the dispute and explores the larger issues of sea power in the region.

Extended, discreet negotiations laid the groundwork for the November 10 meeting between Japanese Prime Minister Abe Shinzō and President Xi Jinping of China on the sidelines of the Asia-Pacific Economic Cooperation summit. On November 7, shortly before the summit took place, Japan’s Ministry of Foreign Affairs issued the following statement.

“Toward the improvement of the Japan-China relations, quiet discussions have been held between the Governments of Japan and China. Both sides have come to share views on the following points:

“1. Both sides confirmed that they would observe the principles and spirit of the four basic documents between Japan and China and that they would continue to develop a mutually beneficial relationship based on common strategic interests.

“2. Both sides shared some recognition that, following the spirit of squarely facing history and advancing toward the future, they would overcome political difficulties that affect their bilateral relations.

“3. Both sides recognized that they had different views as to the emergence of tense situations in recent years in the waters of the East China Sea, including those around the Senkaku Islands, and shared the view that, through dialogue and consultation, they would prevent the deterioration of the situation, establish a crisis management mechanism and avert the rise of unforeseen circumstances.

“4. Both sides shared the view that, by utilizing various multilateral and bilateral channels, they would gradually resume dialogue in political, diplomatic and security fields and make an effort to build a political relationship of mutual trust.”

It is unusual to announce a formal agreement in order to make possible a meeting with the leader of the host country of a major international summit, though it is not unheard of. What does this statement signify? As China accepted the deal after having sought a compromise from Japan, in some sense Japan must have compromised. But where exactly was that compromise? And above all else, why has the issue caused such a high level of bilateral tension?

In reality, the issue of the Senkakus (which the Chinese call the Diaoyu Islands) has merely been a means of further expanding the military “game” between the two nations. As it is most unlikely that the recent agreement will bring an end to the dispute, and the islands seem almost certain to remain a point of contention between Japan and China over the long term, this article will offer a general overview.

Almost Entirely Unfit for Human Habitation

The Senkaku Islands are situated in the East China Sea, 410 kilometers west of Okinawa’s main island, 170 km north of Ishigaki Island, 170 km west-northwest of Taiwan, and 330 km east of the coast of Fujian Province in China. For administrative purposes, the group is a part of the municipality of Ishigaki in the western part of Okinawa Prefecture, and it includes the following islands: Uotsuri (the largest), Kitakojima, Minamikojima, Kuba, Taishō, Okinokitaiwa, Okinominamiiwa, and Tobise. The islands have a total area of 5.17 km2, consisting almost entirely of rocky ground unsuitable for human habitation.

There were no permanent residents on the Senkakus until modern times, meaning that it was terra nullius (land belonging to no nation) under international law. However, it does appear that the seas surrounding the islands were known as fishing grounds to the fishermen of the East China Sea before then, and both the Japanese name of the main island, “Uotsuri,” and the Chinese name for the island group, “Diaoyu,” use terms meaning “fishing.”

From 1885 on, Japan conducted repeated surveys to establish that the Senkaku Islands were in fact terra nullius and, in line with the proper rules for taking possession of territory under international law, formally incorporated the Senkakus into its territory in January 1895. The Treaty of Shimonoseki, which concluded the Sino-Japanese War of 1894–95 with the ceding to Japan by Qing China of Taiwan and the Penghu Islands (Pescadores), was signed in April of that year, but the Senkakus were not mentioned in the treaty.

After the islands became Japanese territory in 1895, the government granted a 30-year lease for the islands of Uotsuri, Kuba, Kitakojima, and Minamikojima to Koga Tatsushirō, a businessman born in Fukuoka Prefecture and living in Okinawa. Koga built a katsuobushi (dried bonito flake) plant and other buildings, and there were people living on the islands until 1940, after which they again became uninhabited.

Postwar US administration

In the Cairo Declaration of December 1943, the leaders of Britain, the United States, and China set forth their intentions “that Japan shall be stripped of all the islands in the Pacific which she has seized or occupied since the beginning of the first World War in 1914, and that all the territories Japan has stolen from the Chinese, such as Manchuria, Formosa, and the Pescadores, shall be restored to the Republic of China.” This stance was carried over to the Potsdam Declaration of 1945, which Japan accepted the terms of, relinquishing its rights to territories including Taiwan (Formosa) and Korea, when it surrendered to the Allied forces at the end of World War II.

In the postwar period the United States administered all of Okinawa Prefecture, including the Senkakus, along with the Amami Islands (part of Kagoshima Prefecture) separately from the rest of Japan, continuing to exercise jurisdiction even after occupied Japan regained its independence under the San Francisco Peace Treaty of 1951.  As the Senkakus were uninhabited, they were used by the US military as firing and bombing ranges. Nobody felt any doubts that they were Japanese territory, and they were treated as such at the time of Japan’s 1945 surrender and of the 1951 peace treaty. Looking back at documents and materials of the time, we can see that the government of the People’s Republic of China also then accepted that the Senkakus were part of Okinawa. At the very least, we can say that there is no history of the islands ever belonging to China.

Then in November 1969, at a summit between Japanese Prime Minister Satō Eisaku and US President Richard Nixon, it was formally agreed that Okinawa would be returned to Japanese administration, the Amami Islands having previously been returned in 1953. On May 15, 1972, Okinawa was reunited with Japan, and naturally this included the Senkakus. However, around this time an unexpected challenge emerged.

Talking Around the Islands Issue

In the autumn of 1968, the year before the Satō-Nixon summit, the United Nations Economic and Social Commission for Asia and the Pacific conducted resource surveys across the East China Sea. The commission, for which Japan, South Korea, and Taiwan were major members, reported the possibility of substantial seabed oil deposits in a 200,000 km2 area of sea northeast of Taiwan. It was not long after this, in 1970, that China began claiming the Senkaku Islands as part of its territory.

In 1972, Japan and China normalized diplomatic relations and in 1978 they concluded a Peace and Friendship Treaty. As would be expected, the Senkaku issue was discussed in the negotiation process. At a meeting between Japanese Prime Minister Tanaka Kakuei and Chinese Premier Zhou Enlai on September 27, 1972, Tanaka asked, “What are your views on the Senkaku Islands? There are people coming to me and saying various different things about them.” Zhou replied, “I don’t wish to talk about the islands issue at this time. It is not good to talk about it now. This has become a problem because of oil. If there was no oil, Taiwan and the United States would not make it into an issue.”

Then at a meeting between Prime Minister Fukuda Takeo and Vice Premier Deng Xiaoping on October 25, 1978, in a manner suggesting he had just recalled something, Deng said, “There is one more thing I would like to say. There are many issues between our countries. For example, there is the issue of what we in China call the Diaoyu Islands and people in Japan call the Senkaku Islands. We do not need to raise this question at meetings like the one we are having today. As I said to Foreign Minister Sonoda [Sunao] in Beijing, we may not be sufficiently wise to resolve this issue in our generation, but the next generation will be wiser and will probably be able to resolve it. It’s essential to take a broad view of this issue.” Prime Minister Fukuda did not reply.

What are China’s Intentions?

Japan has consistently maintained the view that “the Senkaku Islands are clearly an inherent territory of Japan, in light of historical facts and based upon international law,”  that “the Senkaku Islands are under the valid control of Japan,” and that “there exists no issue of territorial sovereignty to be resolved concerning the Senkaku Islands.”

But what are China’s intentions? The Taiwanese government first claimed territorial rights over the islands, so China, which has positioned reunification with Taiwan as a national policy, also staked a claim. Furthermore, as is apparent in Premier Zhou’s words, the discovery of resources in an area previously thought worthless was also clearly a factor.

Based on precedents from international law and the International Court of Justice, if a state has effective control of unoccupied land and the intention to incorporate that land into its territory, it is the international convention that the land becomes the state’s territory. And as it is also the convention that fair and peaceful control of an area considered part of a state’s territory for a substantial period of time brings territorial rights, failing to make appropriate objections to another state’s claiming of land indicates acceptance of that claim.

Japan has governed the Senkaku Islands impeccably according to international rules since 1895, and even after China began to claim territorial rights in 1970, it prioritized relations with Japan over its claim to the islands, as the 1970s summits demonstrate. That is to say, it made territorial claims, but did not argue against Japan’s territorial rights. This is the historical background for Japan’s maintaining that “there exists no issue of territorial sovereignty to be resolved concerning the Senkaku Islands.”

However, in recent years China’s insistence on its territorial claims, intrusion by Chinese vessels into the waters surrounding the Senkakus, and related activity have become more aggressive in nature. China now prioritizes its claims to the islands over relations with Japan. There may be reserves of oil or natural gas in the area, but in that case there are other places around the world where they can be found and many other means of procuring these resources. And if it is a question of China’s standing in the world, then why has it taken so long to act?

For Japan, overturning the boundaries fixed since the San Francisco Peace Treaty would amount to casting doubt on the extent of its sovereignty as redefined after World War II. But what is China so persistently pursuing? Under the conventions of international law, it is not permitted to make a new claim that conflicts with past claims. The reason this issue has escalated to the point where a military clash is feared cannot be explained at the level of such matters as international law and a scramble for resources. Here, I would like to examine the dispute from a different perspective.

A Larger Power Game

The military concept of “sea power” is the most fitting and widely known explanation for how nations establish control over the uninhabited expanses of the sea. US naval strategist Alfred Thayer Mahan (1840–1914) believed that national power in the modern era is dependent on trade, and that ensuring the security of merchant fleets and trade vessels is the key to a country’s destiny. Naval power is for that purpose, and the area in which a country can exert this power when necessary is its sphere of influence and defense zone.

This strategic target of establishing sea power had a major impact around the world in the twentieth century. Mahan gave direct counsel to Japanese combined fleet staff officer Akiyama Saneyuki (1868–1918), and his ideas heavily influenced Emperor Wilhelm II of Germany (1859–1941) and Sergey Gorshkov (1910–1988), who built the Soviet Union’s postwar navy. Liu Huaqing (1916–2011), who was long a central figure in China’s navy and an aide to Deng Xiaoping, was also known to be a follower of Mahan’s theories. In the 1980s, following the conclusion of the Treaty of Peace and Friendship Between Japan and the People's Republic of China and the start of reforms and the opening up of China, Liu set forth the First Island Chain strategy of establishing defensive lines behind which the Chinese navy would have total control and insisted on the need for the navy to have aircraft carriers.

However, even this did not make waves in the East China Sea. From the perspective of sea power, in the postwar era the Senkaku Islands and the East China Sea belonged to neither Japan nor China. Instead, it was an American sea. Because of this, regardless of territorial claims by neighboring countries, Japan neglected military defense of the Senkaku Islands area. In fact, this was true not only for the Senkakus but also the whole of the Sakishima Islands constituting the western part of Okinawa Prefecture, none of which had either US military or Japanese Self-Defense Forces bases ready for actual use, leaving a military vacuum.

Hints at US Decline

Even so, no problems arose until the dawn of the twenty-first century, when dark clouds began to gather over the United States. A succession of events hinted at the waning of US power from the bursting of the dot-com bubble and the 9/11 terrorist attacks, through the increasing quagmire of wars in Afghanistan and Iraq, to the subprime mortgage woes and subsequent financial crisis, alongside the continued polarization of public opinion under the presidencies of George W. Bush and Barack Obama. By contrast, in the same period China experienced rapid economic growth and bolstered its military capabilities.

After the United States withdrew its military from the Philippines in the early 1990s, China strengthened its presence in the Spratly Islands, claiming most of the South China Sea together with the western Spratly Islands, disputed with Vietnam.

In the same way, China has increased its military presence in the East China Sea. In 2004, a submerged Chinese nuclear submarine passed through the Miyako Strait between the main island of Okinawa and Miyako Island to its west. Although the Miyako Strait is an international strait, submarines should surface when passing through according to international law. The submarine was immediately discovered by the SDF and was targeted for sinking exercises several dozen times during its passage. After this incident, Chinese nuclear submarines and other naval vessels have continued their provocative activity, passing through the Ōsumi Strait between the Ōsumi Peninsula in Kyūshū and the island of Amami Ōshima and also the channel between the islands of Ishigaki and Yonaguni (at the western end of the Sakishima group) with the loud support of the Chinese media. In 2013, China established an air defense identification zone over the East China Sea, including the Senkakus and overlapping Japan’s own ADIZ. As a result, military aircraft from the two nations regularly approach each other performing warning maneuvers.

War by Other Means

China has a concept of “three warfares” based on which, before reaching actual conflict, it employs the strategies of media, psychological, and legal warfare to achieve effective control. In this case, the strategies have taken the form of criticizing Japan over the issue of the Senkaku Islands and challenging behavior by its vessels around the Sakishima Islands. Looked at with Mahan in mind, the waning of American power—as China perceives it—has left a military vacuum around the Sakishima Islands, which China seeks to fill. It is a strategically important area, connecting mainland China with the open ocean, and China takes no heed that under international law it is Japanese territory, sea, and airspace.

Naturally, Japan is not simply looking on idly. After the September 2010 incident in which a Chinese fishing trawler collided with a Japan Coast Guard ship, amid the anti-Japanese demonstrations in China that followed, end-of-year SDF maneuvers brought a regiment of land-based anti-ship missiles to Amami Ōshima, demonstrating the will to blockade the Ōsumi Strait. Then, after nationalization of the Senkakus in 2012, continuing coercive behavior by China included incursions into Japanese waters by its vessels and aircraft and a Chinese naval ship locking weapon-targeting radar on an SDF vessel. Japan responded by stationing anti-ship missiles on Miyako and the main island of Okinawa in its autumn 2013 maneuvers, ready to blockade the Miyako Strait.

After Abe Shinzō became prime minister in December 2012, a long-pending plan for an SDF base on Yonaguni (the westernmost inhabited island of the Sakishima group) was set into motion, along with the formation of a marine unit to be stationed there. This means that even without a US military presence, Japan will be able to defend its southwestern islands by itself and gradually develop the capability to impose a blockade; this is a red rag in the face of China.

President Obama and the US Congress still view responsibility for defense of the Senkakus as falling under Article 5 of the Japan-US Security Treaty and have made public statements to that effect, indicating that the United States has no intention of leaving a military vacuum in the area.

Regarding China’s increasingly assertive international stance, it is often difficult to tell whether its government’s actions are actually aimed at other countries or a domestic audience. In the case of the Senkakus, we can say at least that there is a will to prevent the situation deteriorating any further. By “shelving” the Senkaku issue, Beijing can avoid the claim that it is heightening military tension.

(Originally written in Japanese by Mamiya Jun of the Nippon.com editorial department and published on November 14, 2014.)


Serita Kentarō. Nihon no ryōdo (Japan’s Territory). Chūōkōron Shinsha, 2002.
Ogawa Kazuhisa and Nishi Takayuki. Chūgoku no sensōryoku (China’s Military Capability). Chūōkōron Shinsha, 2014.
Alfred Thayer Mahan. The Influence of Sea Power upon History: 1660–1783. Little, Brown and Company, 1890.

Self-Defense Forces China Abe Shinzō APEC Okinawa Senkaku Islands Xi Jinping military navy