The Senkaku Islands and the waters surrounding them are rapidly becoming the center of a fierce rivalry between Japan and China.
Since his rise to power in 2013, Chinese President Xi Jinping has emphasized the importance of the seas, and has stressed the necessity for China to become a maritime power. All the foreign powers that invaded China in the nineteenth and early twentieth century had one thing in common, they all came from the sea. Therefore, if China is to “achieve its dream of National Renaissance”, it must master the seas first.
Chinese naval assertiveness in the South China Sea (SCS) has been coming to global attention for years now. In effect, the South China Sea’s maritime routes are arguably the busiest in the world today. The United Nations Conference on Trade and Development reported that, in 2016 alone, an estimated $3.37 trillion worth of goods, accounting for 21% of all global trade, sailed through the South China Sea. However, the SCS is merely a corridor to access East Asia.
In fact, most of the containerships sailing through the SCS are headed towards East Asian ports; particularly the port of Keelung (Taiwan), the port of Shanghai (China), the port of Pusan (South Korea) and the port of Nagasaki (Japan). Therefore, the East China Sea holds tremendous strategic importance. This is why the Senkaku Islands are so relevant in today’s East Asian geopolitical landscape.
The Senkaku Islands are an archipelago of uninhabited islands laying at approximately 92 nautical miles (nm) from both Taiwan and the Japanese island of Ishigaki (in the Okinawa Prefecture), and 178 nm from mainland China. The archipelago is composed of five islands and three barren rocks, ranging in size from 800 m2 to 4,32 km2 (Uotsuri Island), for a total landmass of 6,30 km2.
The archipelago lies at a mere 170 km away from the Taiwan Strait, at the edge of both Chinese and Japanese EEZs. Therefore, if the islands were to be militarized with, for example, long range ballistic missiles, whatever power controls them could be able to interdict access to all East Asia. Therefore, the strategic location of the archipelago is one of the reasons why the Senkaku Islands are claimed by both Japan, China (called Diaoyu Islands in Mandarin Chinese) and Taiwan (called Tiaoyutai Islands in Taiwanese Mandarin).
The archipelago is currently under Japanese jurisdiction. In 2012, the Japanese government went as far as buying the islands from the various private Japanese organizations that owned them in the past, arousing the anger of Beijing. Let us trace back the history of the contested archipelago. The Chinese authorities say the islands were firstly sighted in 1372 by the sailors of the Ming Dynasty. Subsequently, all the major islets of the archipelago were identified and named in a 1534 Ming Dynasty record, marking allegedly the sea frontier of the Ming Empire (and later Qing), as appurtenances of the greater island of Taiwan.
After the decisive defeat that the Empire of Japan inflicted on the Qing Dynasty in the first Sino-Japanese war, the Chinese were pressed into signing the Treaty of Shimonoseki (1895), with which China ceded the island of Taiwan to Japan (Article 2B), together with all the minor islets appertaining to the main island. However, the Japanese authorities state that, ten years prior to the signing of the Treaty of Shimonoseki, the Japanese government led a survey of the islands and found them uninhabited, claiming them for Japan under the international law principle of Terra Nullius.
The Senkaku Islands were officially incorporated into the Japanese Okinawa Prefecture a few months before the signing of the Treaty of Shimonoseki. Therefore, the Japanese authorities claim that the annexation of the Senkaku Islands was an entirely separate legal event to the annexation of Taiwan. A few years after the end of WWII in 1951, the Japanese themselves were now pressed by the Americans into signing the Treaty of San Francisco, with which they renounced all claims over the island of Taiwan (together with all related lesser islands around it) in order to establish the Republic of China (Taiwan) on the island. However, the Japanese claim that the Senkaku where never a part of the lesser islands belonging to Taiwan, and that the archipelago was annexed to the Okinawa prefecture in 1895 under the law of Terra Nullius.
Therefore, the Japanese authorities hold that the Treaty of San Francisco cannot grant Taiwan the ownership of the Senkaku archipelago. Further weakening Chinese and Taiwanese claims over the Senkaku Islands is the fact that they have not claimed the islets up until decades after the end of WWII. After the end of the War, the Americans occupied the Okinawa Prefecture until 1972 and, according to Washington, that prefecture always included the Senkaku Islands. However, the Chinese authorities claim that the islands are fully part of the lesser islands belonging to Taiwan, and that Taiwan never claimed ownership of the Islands before the 1970s because it was too economically and politically dependent on the United States.
The Chinese continue in their claim over the Senkaku by saying that, not recognizing Taiwan as a sovereign Nation but as a breakaway province of China, the Senkaku belong by extension to China as well. However, further weakening the Chinese claims over the archipelago is the fact that there are Chinese maps and atlases of the 1950s and 1960s that clearly label the islands as Senkaku, showing them as part of the Japanese Okinawa Prefecture. In 1968 a United Nations Survey conducted around the Senkaku revealed the possible presence of vast quantities of oil and natural gas in the area. In addition, the East China Sea is one of the most productive bodies of water in the world when it comes to fishing: it is estimated that, since the 1950s, almost 5% of all the fish caught around the world came from the East China Sea.
In 1971, three years after the redaction of the abovementioned UN survey, and just one year before the Americans relinquished administrative control over the Okinawa Prefecture, China made its first claim over the Senkaku Islands, calling them the Diaoyu islands. However, Japan ignored all Chinese claims and, beginning in 1972, has again administered the Senkaku Islands as part of its westernmost prefecture. The US Government has also continuously stated that the Senkaku archipelago belongs to Japan; as such, the Senkaku fully fall into the 1960 Treaty of Mutual Cooperation and Security between the US and Japan.
This treaty obliges the US to come to the defense of Japan in the case of a foreign attack on any of Japan’s islands, including the Senkaku. US and EU estimates around the economic value of the hydrocarbon reservoirs in the area are to the effect of 200 million barrels of oil and up 60 billion cubic feet worth of natural gas. These numbers, although not impressive on a global scale, are indeed very relevant for counties like China and Japan, which are almost entirely dependent on the Gulf countries for their hydrocarbon’s supplies.
However, given Japan’s pacifistic constitution and overhaul international posture after WWII, the land of the rising sun has never made military use of the Senkaku Islands or economic use of the hydrocarbon reservoirs in the area around them, preferring to uphold the status quoinstead. In effect, the islands remain uninhabited to this day. However, such status quo can effectively change at any moment. Although Japan has never militarized the Senkaku archipelago so far, the same cannot be said for the rest of the Okinawa Prefecture. Recently, Japan has established a military base in Younaguni Island, the westernmost island of its westernmost archipelago (the Yaeyama Islands).
Yonuaguni is the westernmost inhabited island of Japan, and it is only 29 km2 in size. However, the modest proportion of the island belies its strategic importance. In fact, Yonaguni lays at only 58 nm (108 km) from the east cost of Taiwan (Yilan County), a position that grants it immense strategic depth. Yonaguni locals say that, on a clear day, Taiwan can be sighted with the naked eye form the westernmost tip of their island. Clearly, the fact that Yonaguni was chosen to host a new military basis was not a coincidence.
In 2016, JGSDF Camp Yonaguni was established, and there are already plans to expand the facility giving it new capabilities, including an electronic warfare operations unit and a surface-to-air missile unit. Younaguni lies at a mere 162 km from the Senkaku Islands. Furthermore, in 2019, the increasing tensions in the East China Sea prompted the Japanese government to open two more military bases in the Island of Amami Oshima (Amami Islands, Satsunan Islands, Ryukyu Islands, Kagoshima Prefecture), called JGSDF Camp Amami and JGSDF Vice-Camp Setouchi.
Before the purchase of the Senkaku archipelago by the Japanese government in 2012, the islands were administered by the city of Ishikagi, major city of the homonymous island, and part of the Yaeyama Islands, in the Okinawa prefecture. After the nationalization of the islands by the Japanese government, the number of Chinese Coast Guard’s incursions around the Senkaku Islands increased thirteen-fold (it is also when, coincidentally, Xi Jinping rose to power).
The Japanese Navy has therefore significantly increased the number of its Coast Guard vessels at Ishigaki, to defend its fisherman fishing in the waters around the Senkaku, against the incursions of the Chinese Coast Guard. On March 2023, the increasing tensions in the area have prompted the Japanese government to open yet another military base in Ishigaki Island itself, called JGSDF Camp Ishigaki. In the case of a conflict in the Taiwan Strait, it is plausible that China will try to lure the Japanese and the Americans around the Senkaku by increasing their presence in the area. In so doing, Japanese and American forces would be drawn away from Taiwan, creating a vacuum and an opportunity for Beijing to strike with force on the island.
This strategy alone could buy the Chinese some precious time before Allied forces come to the defense of Taiwan. One thing is for certain, the South China Sea, the Strait of Taiwan and the East China Sea are now entangled in a web of volatility and uncertainty that is ready to deteriorate at any moment. In this scenario, the Senkaku Islands play a role which should not be underestimate.
