The Strategic Value of Territorial Islands from the Perspective of National Security

1. Introduction

Lying between northern Kyushu and the Korean Peninsula, Okinoshima Island has been considered the sacred abode of the god of the sea since ancient times. Today, it is open to the public only one day a year--May 27--to commemorate the victory in the Battle of Tsushima during the Russo-Japanese War. During that war, a naval watchtower was built on the island to monitor the approach of the Baltic Fleet. A valuable witness of the historic battle was a boy working at the Shinto shrine on the island, who saw the battle unfold and the communication using signal flags between the warships and the island.

The Japanese archipelago, situated off the northeastern coast of the Eurasian continent in the Pacific Ocean, consists of 6,800 large and small islands. National security threats today, just as in the past, come from across the sea.

During the Pacific War, the US adopted a "leapfrogging" strategy, successively gaining footholds on such Pacific islands as Midway, Guam, and Iwo Jima (Ioto Island), enabling it to launch attacks on the Japanese mainland. With the end of World War II and the start of the Cold War, the Japanese mainland and the Nansei (Ryukyu) Islands to the southwest of Kyushu effectively came to be viewed by both Japan and the United States as a containment line against Soviet naval deployment forces. In response, the Soviet Navy turned the Sea of Okhotsk into a strategic naval bastion for its ballistic missile submarines, with the four islands in the Northern Territories constituting part of this "keep out" zone. Today, the naval force of China's People's Liberation Army is rapidly expanding its activities in the high seas, but its vessels must first pass through Japan's Nansei Islands to reach the western Pacific and through the many islands with conflicting territorial claims in the South China Sea to reach the Indian Ocean.

From the viewpoint of military strategy, islands have played such important roles as warning and surveillance posts, logistic bases for operations launched from the sea against mainland targets, and fortifications to prevent intrusions by hostile ships. Today, they also provide countries with baselines to measure jurisdictional waters. Since the UN Convention on the Law of the Sea (UNCLOS) came into force, national governments have been able to establish exclusive economic zones extending beyond their territorial waters, within which they retain certain sovereign and jurisdictional rights. The EEZ can extend up to 200 nautical miles from the baseline, making it an important body of water for the military strategies of both the coastal and seafaring states. In littoral military operations, the jurisdictional waters stretching from the shore can be an important area for both a defense-in-depth strategy, as seen from the continent, and power projection, as seen from the sea. Military operations within the EEZ are interpreted quite differently from country to country, though, with some, notably the United States, claiming that military ships may freely navigate, explore, and carry out exercises, and others like Brazil banning foreign navies from conducting exercises in their EEZ. Legal interpretations of naval operations within an EEZ can have great bearing on national security policy, so remote islands that serve as bases of EEZ claims have gained new importance from the vantage point of military strategy.

Countries attach geographical, economic, and cultural importance to remote islands as they provide bases for extended territorial claims over land, sea, and airspace; sovereign rights to marine resources in the EEZ and continental shelf; and nurturing grounds for the culture and lifestyles of residents. Depending on their geostrategic characteristics, islands can also have great defense and security implications for the international community. All nations take such characteristics into account when formulating their respective defense and national security strategies. This paper examines the strategic value of the islands possessed or claimed by Japan from the defense and security perspectives. It focuses primarily on the Nansei Islands, including the Senkakus, making references to the Northern Territories and Okinotorishima Island--which are inherent territories of Japan--where applicable.

2. The Strategic Value of the Senkakus and Northern Territories

A. The PLA Navy and Nansei Islands

A Chinese nuclear-powered submarine, believed to be in the Han-class, violated Japan's territorial waters between Ishigakijima Island and Taramashima Island on November 10, 2004, crossing submerged from the Pacific Ocean to the East China Sea. The submarine is thought to have left a Chinese naval base, traversed the Nansei Islands, and headed toward Guam before turning back to China. Japan's Maritime Self-Defense Force, which was monitoring the vessel, issued warnings against any intrusions into territorial waters, but after such warnings were ignored, the MSDF undertook maritime security operations. The submarine fled back to China through the East China Sea. Concluding that the vessel belonged to the PLA Navy, Tokyo lodged a protest against Beijing, which, while admitting that a naval submarine did violate Japan's waters, refused to apologize, saying the intrusion was due to a technical problem.

Countries have sovereignty over territorial waters, and the ships of all states "enjoy the right of innocent passage" provided they adhere to UNCLOS (see Articles 17 and 19) and other international laws. Article 20 of the convention stipulates, moreover, "In the territorial sea, submarines and other underwater vehicles are required to navigate on the surface and to show their flag." Because of the clandestine nature of their activity, though, submarines generally sidestep this provision by avoiding the territorial waters of other states.

All Chinese naval bases face either the East or South China Sea; in order to enter the western Pacific, naval ships must thus pass through either the Nansei Islands or the Bashi Channel. Another alternative would be to use the Tsugaru Strait, traversing the Sea of Japan via the Tsushima Strait, but this would mean making a much longer voyage and, more importantly, coming under Japanese, South Korean, and Russian scrutiny--something no doubt undesirable from the viewpoint of military operations. Most Chinese fleets deployed in the western Pacific are based at Ningbo, south of Shanghai, and usually pass between Okinawajima Island and Miyakojima Island--a route enabling relatively extensive use of the open sea (Figure 1).

In October 2008, four years after the submarine intrusion, four Chinese naval vessels crossed the Tsugaru Strait to reach the Pacific, moving south and returning to China via the Nansei Islands and the East China Sea. The following month, four vessels sailed into the Pacific between Okinawajima Island and Miyakojima Island. Since then, Chinese naval vessels have regularly carried out operations in the western Pacific as follows:

June 2009 Five vessels pass between Okinawajima Island and Miyakojima Island for operations northeast of Okinotorishima Island.

March 2010 Six vessels pass between Okinawajima Island and Miyakojima Island into the Pacific. Ten vessels pass between Okinawajima Island and Miyakojima Island the following month for operations west of Okinotorishima Island.

June 2011 Eleven vessels pass between Okinawajima Island and Miyakojima Island for operations in the Philippine Sea.1

Figure 1: Route used by Chinese naval vessels: Okinawajima Island and Sakishima Islands

Note: Maps of the Senkaku Islands and the surrounding waters were created by the OPRF based on 1:25,000 scale charts published by the Geospatial Information Authority of Japan.

Figure 2 is a graphical representation of such naval movements.

Figure 2: Recent Chinese activities in the waters near Japan

Source: Ministry of Defense, Defense of Japan 2011 (Annual White Paper).

Figure 3: The First and Second Island Chains

Source: US Department of Defense, "Military and Security Developments involving the PRC 2011"

B. Disputes over chains of islands

Key concepts in the PLA Navy's access to the western Pacific are the "first island chain" and "second island chain" (Figure 3).

The navy is regarded as seeking a phased advance into the Pacific from the Chinese mainland. The first phase is to secure operational capabilities in an area stretching from the Nansei Islands to the Philippines, and the second is to expand this area to the Ogasawara Islands, Guam, and Indonesia. The concept of the first and second island chains roughly corresponds to the "defense line" idea developed in the early days of the Cold War by US Secretary of State Dean Acheson. Some Chinese naval officials contend, therefore, that the island chain concept is a US military construct intended to seal off Chinese advancement into the Pacific. Be that as it may, a clear goal of Chinese military policy has been to secure operational capabilities inside the first island chain by 2010. The island chain concept may therefore be said to be a byproduct of the interplay of US and Chinese strategies.

The US Quadrennial Defense Review published in February 2010 lays down a "joint air-sea battle concept" with a view to securing access to the East and South China Sea from the Pacific as part of a US national security strategy. The aim of this concept is stated as to counter anti-access/area-denial (A2/AD) challenges to America's freedom of action. In a nutshell, though, this is an operational concept that anticipates a war with China within the first island chain on the Asia-Pacific front.

In May 2010, the Center for Strategic and Budgetary Assessments, a US think tank, issued a report titled "AirSea Battle: A Point-of-Departure Operational Concept," which proposes a geostrategic concept for breaking through the two island chains from the western Pacific (Figure 4).

Figure 4: Geophysical features of the Western Pacific theater

Source: CSBA, "AirSea Battle" (presentation slide deck), May 18, 2010

Because the first and second island chains are likely to become the focus of any military showdown between the United States and China, the Nansei Islands are of pivotal importance from a security viewpoint.

A Chinese naval fleet crossed the first island chain to enter the western Pacific for the first time in 2008. The intrusion into Japan's territorial waters by a Han-class submarine four years earlier in 2004, though, remains largely a mystery. Was it an intentional encroachment; was it really just due to a "technical problem," as Beijing claimed; or was it to elude tracking by Japan Coast Guard vessels? Since 2008, Chinese fleets have been moving into the western Pacific through a lane north of Ishigakjima Island and between Miyakojima Island and Okinawajima Island.

What is problematic is the passage of submarines. In 2010 submarines sailed through the Nansei Islands along with other vessels in the naval fleet on the ocean surface, as required by UNCLOS. But in 2011, a submarine is believed to have entered the Pacific while remaining submerged. What do these two incidents suggest about Beijing's intentions? While many hypotheses have been postulated, one is that Beijing regards the 2011 route as passing through the open sea. Be that as it may, there is no denying that the Nansei Islands represent a fragile choke point for the Chinese navy's advance into the Pacific and also the most effective operational line of containment for Japan and the United States.

As Figure 1 shows, the Senkaku Islands lie on the western edge of the sea between Okinawajima Island and Miyakojima Island. From China's perspective, having to navigate around the islands to claim innocent passage for its fleet is no doubt a great nuisance. If the Senkakus were owned by China, on the other hand, its navy would have a much freer hand in conducting its operations.

Turning north, the Soviet Union claimed the Sea of Okhotsk during the Cold War as a "keep out" zone, using the Kuril Islands and the Northern Territories as a line of defense to deploy ballistic missile submarines capable of striking targets on the US mainland. Today, Russia is stepping up military activities around the Kurils, perhaps in anticipation of the full-scale opening of the Northern Sea Route and also in step with Moscow's large-scale 2007-15 socioeconomic development plan for the Kurils announced in 2006. In September 2011, Russia conducted its biggest military exercise in the seas near the Kurils and the Northern Territories in the post-Soviet era, involving 20 naval vessels, along with bombers. The islands surrounding Japan thus always appear to be at the frontlines of the country's defense and national security.

3. Islands as EEZ Baselines

A. Conflicting claims over military operations in the EEZ

On April 1, 2001, a US E-P3 electronic surveillance aircraft and a Chinese jet fighter collided in midair some 110 kilometers southeast of Hainan. Beijing harshly criticized the US military for carrying out reconnaissance activities along China's coast, while Washington asserted it was free to carry out military operations in the area.

The seas below the aerial collision were part of China's exclusive economic zone, leading to debate on whether military or reconnaissance activities may be undertaken in other countries' EEZs. Even before the collision, countries had different interpretations. Brazil, Malaysia, and India, for example, maintained that reconnaissance activities could not be undertaken within another country's EEZ without the consent of that country. Conversely, many traditional maritime countries, including the United States, asserted that Articles 58 and 87 of UNCLOS confers the "freedoms . . . of navigation and overflight" in the EEZ.

China has adamantly refused to allow other countries to conduct military operations, particularly reconnaissance activities, in its EEZ. On March 8, 2009, eight years after the E-P3 collision, the Impeccable, an ocean surveillance ship of the US Navy, became the target of tenacious harassment from Chinese naval vessels, patrol boats, and fishing ships while operating 120 kilometers off the coast of Hainan in China's EEZ. Beijing is very sensitive about reconnaissance around Hainan, as the island hosts a naval base where China's most advanced submarines are deployed. Just four days prior to the Impeccable incident, another US Navy surveillance ship, the Victorious, was similarly harassed by fishery patrol vessels in the Yellow Sea.

Beijing often defends these actions by maintaining that the EEZ should be used exclusively for peaceful purposes, not military operations, but it must be pointed out that China, too, conducts a variety of research activities inside Japan's EEZ without prior notification. This is clearly a double standard.

UNCLOS makes no direct mention of military or reconnaissance activities in the EEZ. As the EEZ is a concept ascribing rights, jurisdiction, and duties over resource maintenance and environmental protection to the coastal state, military operations are not necessarily ruled out. But at the same time, Article 58 of UNCLOS notes, "States shall have due regard to the rights and duties of the coastal State," a vaguely worded provision that could be interpreted as restricting countries from carrying out operations with naval ships in a coastal state's EEZ. A naval exercise, for instance, could easily impact on the zone's resources or the environment.

Military and reconnaissance operations in waters that carry security implications are indispensible for national defense and even survival, but such operations, when conducted by other states inside one's EEZ, can pose a national security threat. Islands that serve as baselines for the demarcation of the EEZ, therefore, have great significance for both countries claiming they have legitimate rights to carry out military and reconnaissance operations and those that disallow such activities.

B. The importance of the Senkakus and Okinotorishima Island

While Japan has not taken an official stance on military and reconnaissance operations in the EEZ, as a maritime state it is thought to uphold the principle of the freedom of the sea. Because the country's alliance with the United States forms the crux of its national defense, moreover, the position of the Ministry of Defense and the Self-Defense Forces is believed to be in line with that of the US Navy.

Japan's flexible attitude toward the activities of foreign naval vessels in its EEZ is no doubt highly welcomed by China, as it enables the PLA Navy to conduct exercises in waters surrounding Japan and to make forays into the western Pacific. At the same time, Japan has repeatedly protested the incursions of Chinese research vessels into Japan's EEZ without prior notification, assumingly for scientific research and resource exploration. UNCLOS stipulates that marine scientific research must be conducted with the agreement of coastal states, which have sovereign rights over resources, so Japan's protests are quite legitimate. Should Japan legally disallow foreign military and reconnaissance operations in its EEZ, the activities of China's navy would be seriously circumscribed. As shown in Figure 5, the size of Japan's EEZ is enormous. China would be unable to criticize Japan should it adopt a tougher stance, though, since China itself takes such a stance toward other countries' military and reconnaissance operations in the South China Sea.

Figure 5: Japan's Exclusive Economic Zone

Source: Japan Coast Guard

The Senkaku Islands are just west of the route passing between Okinawajima Island and Miyakojima Island used by the PLA Navy to reach the western Pacific. When a Chinese naval fleet that includes a submarine approaches Okinawajima Island and Miyakojima Island, it needs to remain vigilant of Japanese and US monitoring. A Chinese fleet's operations would be adversely affected should its activities be restricted in Japan's EEZ, as measured using the Senkakus as a baseline. The adverse effect is likely to be even bigger than the restrictions on innocent passage mentioned earlier in this paper.

What are the real aims of China's now annual operations in the western Pacific? Figure 4 describes the geophysical factors that need to be taken into account for the US Navy to deploy forces from the US mainland and Hawaii to the western Pacific. In a contingency, China is expected to attempt to halt US naval advancement to a point between the first and second island chains. China, too, no doubt has similar contingency plans. As the figure shows, the main theater of warfare would be a triangle formed by the Japanese mainland (namely, US bases at Yokosuka and Sasebo), Guam, and Okinawajima Island. Thus, the Chinese navy needs to maintain adequate access to this triangle during peacetime as well.

UNCLOS provisions are predicated on peacetime conditions, and in case of a contingency, military operations take precedence, not only in an enemy state's EEZ but also in its territorial waters. Exercises for such operations must be conducted before any war breaks out to test their appropriateness and feasibility, and data regarding ocean weather and other countries' monitoring systems must be collected to enable submarines to operate effectively. From the Chinese perspective, Japan's Okinotorishima Island and the EEZ the island confers pose a considerable hindrance to such activity.

As Figure 6 shows, Okinotorishima Island is located roughly at the center of the triangle that is expected to become the main theater of a possible US-China war. Japan's stance toward the operations of other states' naval vessels thus has crucial significance for China's contingency plans. The possession of Okinotorishima Island, therefore, gives Japan an immeasurable advantage in defense strategy.

Figure 6: The EEZ conferred by Okinotorishima Island

Source: Japan Coast Guard Annual Report 2011

4. Protecting strategic interests

A. Chinese and Russian responses

In 1992, China enacted the Law of the People's Republic of China on the Territorial Sea and the Contiguous Zone, Article 2 of which stipulates that the "land territory of the People's Republic of China" includes the Senkaku (Diaoyu) Islands belonging to Japan and the Spratly (Nansha) Islands with disputed claims. This law addresses threats to the defense and security of China's territorial islands and gives the Chinese navy and law enforcement officials the right to act, such as when Japanese actions on the Senkaku Islands are perceived to pose such a threat, even during peacetime.2

Maritime law enforcement agencies in China include not only the navy but also Marine Surveillance, the Maritime Police, the Maritime Safety Administration, and the Fisheries Law Enforcement Command. China Marine Surveillance is charged with protecting the country's maritime interests and operates under the command and supervision of the State Oceanic Administration. The waters under its jurisdiction are stipulated in the Law of the People's Republic of China on Island Protection, which came into force in 2010. The ships that patrol the Senkaku Islands fall under the jurisdiction of the East China Sea division. Incidentally, one of the ships involved in the incident with the Impeccable was the Haijian 83 of the South China Sea division.

Ships named haixun belonging to the Maritime Safety Administration are responsible for marine traffic control and for search and rescue. The Fisheries Law Enforcement Command, meanwhile, is part of the Fisheries Management Bureau in the Ministry of Agriculture and is charged with monitoring foreign fishing vessels and protecting Chinese ships. In June 2010, the command's Yuzheng 311 aimed its gun at an Indonesian patrol boat, pressuring it to release a Chinese fishing boat that it had seized. The China Maritime Police, meanwhile, is a part of the Border Control Department, a paramilitary police force in the Ministry of Public Security charged with guarding the coast and conducting maritime policing activities. These four maritime law enforcement agencies, along with the General Administration of Customs, constitute what are sometimes referred to as the Five Dragons.

Some contend that compared to other countries, there are too many such organizations in China, resulting in an excessive branching out of responsibilities; coordination among them is seen as weak, and troop strength as inadequate. But one must recognize that when these law enforcement agencies are combined with the country's naval strength, China has an undeniably powerful naval presence. Above all, domestic laws clearly articulate that islands are to be defended, and these provisions are duly executed.

Russia's oceanic security policy is based on its Maritime Doctrine through 2020, approved in 2001, as well as on the Maritime Activity Strategy for the period until 2030 and the Military Doctrine of the Russian Federation, both adopted in 2010. The Maritime Doctrine contends that the Russian Navy has a duty to protect Russian sovereignty in its internal waters and territorial sea; Russian jurisdictional rights in its EEZ and continental shelf; and the freedom of high seas.3

Inasmuch as the fundamental principles of UNCLOS, an international peacetime law that defines the EEZ, are to promote the peaceful settlement of disputes and international cooperation, the Russian doctrine is unusual in assigning the navy to protect the nation's interests in the EEZ. In addition, Moscow is now spending huge sums to develop infrastructure and port facilities in the Kuril Islands, around the Sea of Okhotsk, and along the coast of the Sea of Japan under the special socioeconomic development plan for the region for 2007-15. Given these developments, Russia is likely to steadily strengthen its military presence around the Kuril Islands and the Northern Territories and in the Sea of Okhotsk. This will also increasingly elevate the strategic importance of the Northern Territories from the Russian perspective.

B. Japan's countermeasures

Much of the strategic value islands have is related to their geographic potential. For Japan, such potential of its territories in the Nansei Islands forms a core element of its defense and security strategy. The islands are of great geographic importance not only for Japan's security but also for that of its neighbors and allies. As such, Japan's sovereignty over these islands has high strategic value. The same can be said for the Okinotorishima Island, located in the middle of the western Pacific "triangle" that is important to Washington's naval strategy. The Northern Territories similarly confer great value to Russia, which now occupies the islands.

Japan thus needs to strengthen effective control of its territorial islands, particularly the Nansei Islands--including the Senkakus, which China claims as its own--both legislatively and institutionally. Article 26 of the April 2007 Basic Act on Ocean Policy states: "The State, with regard to the remote islands, shall take necessary measures including conserving the seacoasts and others, securing the safety of navigation as well as establishing the facilities for the development and use of ocean resources, conserving natural environment in adjacent sea areas, maintaining infrastructure for the life of inhabitant and executing others, in consideration of such fact that the remote islands bear an important role in conserving our territorial sea and the Exclusive Economic Zone and other areas, and in securing the safety of navigation in the development and use of ocean resources as well as in conservation of the marine environment."

In December 2008, meanwhile, the Headquarters for Ocean Policy adopted a basic policy on the preservation and management of islands in accordance with the Basic Act on Ocean Policy. Additional laws are needed, though, to guard and defend Japan's remote islands. The Maritime Self-Defense Force should be allowed to augment the efforts of the Japan Coast Guard to monitor activities around remote islands and, if necessary, to deploy troops for their defense.

The security of Japan's territorial islands has great bearing on the regional security environment. For that reason, it is important to maintain Japan's advantage in the balance of power in the seas surrounding the Nansei Islands, such as by further reinforcing the Japan-US security framework. In negotiating the realignment of US forces, including the transfer of Marine units from Okinawa, Japan must not lose sight of the importance of enhancing deterrence around the Nansei Islands.

An EEZ regime can become a double-edged sword for the security of any country. Efforts to restrict military activity in the EEZ may succeed in mitigating threats from the sea, but at the same time, they may hinder movement into the high seas and weaken the defense posture of an allied naval power. As a maritime nation whose defense is predicated on its alliance with the United States, Japan should seek to build a regime that is as free of restrictions as possible on the military use of exclusive economic zones.

Recommended citation: Akimoto Kazumine, "The Strategic Value of Territorial Islands from the Perspective of National Security," Review of Island Studies, October 9, 2013, /islandstudies//research/a00008/. Translated from "Tosho no senryakuteki kachi," Tosho Kenkyu Journal, Vol. 1 (June 2012), pp. 54-69; published by the OPRF Center for Island Studies.

  1. Data from Defense of Japan 2011 (Annual White Paper), Ministry of Defense, October 2011, p. 83. []
  2. Article 8 of the Territorial Sea Law says, "The Government of the People's Republic of China has the right to take all necessary measures to prevent and stop non-innocent passage through its territorial sea. Cases of foreign ships violating the laws or regulations of the People's Republic of China shall be handled by the relevant organs of the People's Republic of China in accordance with the law." []
  3. Detailed descriptions of Russian maritime strategy are contained in Tange Hiroya's "Roshia no kaiyo dokutorin" (Russia's Maritime Doctrine), Hokkyokukai kiho, no. 10 (Tokyo: Ocean Policy Research Foundation, September 2011), and Tomomori Takehisa's "Roshia Renpo gunji dokutorin ni tsuite" (About the Russian Federation's Military Doctrine), Kaiyo anzen hosho joho geppo, February 2010 (Tokyo: Ocean Policy Research Foundation). []

AKIMOTO Kazumine

Senior Research Fellow at the Ocean Policy Research Foundation. Previously served in the Maritime Self-Defense Force, the National Institute for Defense Studies, and other organizations. Is a specialist in maritime security. Publications include “Sea Lane Defense in the Eurasia Blue Belt,” Journal of International Security, vol. 35, no. 1 (Japan Association for International Security, June 2007), and “Nichi-Bei domei to shi kontororu ”(The US-Japan Alliance and Sea Control),Hato199 (Maritime Self-Defense Force, November 2008).