The islands of Dokdo, known as Takeshima in Japan, remain one of the most persistent territorial disputes in East Asia. Located in the Sea of Japan, this remote group of islets has been a source of international friction for decades. The conflict pits South Korea, which exercises de facto control, against Japan, which claims sovereignty under the name Takeshima. Understanding the physical geography of these islands is crucial for appreciating the depth of the dispute. This article provides a comprehensive overview of the geological features, historical evolution, legal positions, and strategic significance of Dokdo/Takeshima.

More than just rocks in the sea, Dokdo/Takeshima symbolizes national identity and territorial integrity for both nations. The surrounding waters are rich in resources, and the islands occupy a strategic location. This analysis aims to present a balanced view while highlighting the key issues that sustain the dispute.

Physical Geography of Dokdo/Takeshima

Location and Geological Formation

Dokdo/Takeshima is situated at approximately 37°14′N 131°52′E, about 87 kilometers southeast of Ulleungdo, South Korea, and 157 kilometers northwest of the Oki Islands, Japan. The archipelago consists of two main islets, Dongdo (East Islet) and Seodo (West Islet), along with 89 smaller rocks and reefs. The total land area is 0.18 square kilometers, with Seodo being the larger at 0.088 square kilometers and Dongdo at 0.073 square kilometers. The highest elevation is on Seodo, rising 168 meters above sea level.

Geologically, the islands are of volcanic origin, formed during the Miocene era. The rocks are predominantly trachyandesite and basalt, with some pyroclastic deposits. The coastline is characterized by steep cliffs and rocky shores, with few beaches. The terrain is rugged, with limited soil development. The islands are subject to strong winds and wave erosion, which shape their jagged appearance.

Climate and Ecosystem

The climate is temperate oceanic, influenced by the Tsushima Current. Winters are cold and windy, with average temperatures around 1°C, while summers are mild, averaging 20°C. Precipitation is moderate, about 1,500 mm annually, with frequent fog from June to August. The islands are often buffeted by strong winds, which limit vegetation.

Despite the harsh conditions, the marine ecosystem is rich and diverse. The surrounding waters are part of the East Sea's productive fishing grounds, supporting species like chub mackerel, Pacific saury, and Japanese anchovy. Seabed communities include kelp forests and coralline algae. The islands are a crucial breeding site for seabirds, such as the black-tailed gull (Larus crassirostris) and the streaked shearwater (Calonectris leucomelas). The Korean government has designated the area as Natural Monument No. 336 to protect the bird populations. Marine mammals like the spotted seal (Phoca largha) are also observed in the region.

Maritime Context

The waters surrounding Dokdo/Takeshima are part of the Ulleung Basin, an area of deep sea and rich currents. The Tsushima Current, a branch of the Kuroshio Current, flows northward, bringing warm water and influencing marine life. This current creates a convergence zone with the cold Liman Current from the north, resulting in high biological productivity. The seabed features include volcanic ridges and sedimentary basins with potential for hydrocarbon deposits. The maritime area is also important for navigation, as it lies along the route from the Pacific to the Sea of Japan.

Historical Background

Early Records and Claims

Korean claims trace back to ancient times. According to the Samguk Sagi (History of the Three Kingdoms), the island of Usan-guk was a domain of the Silla kingdom in 512 AD. Later, during the Joseon Dynasty, maps such as the Dongguk Yeojido (15th century) and the Daedongyeojido (19th century) depict Dokdo as Korean territory. Korean fishermen regularly used the islands as a base for fishing and sea lion hunting.

Japanese documents from the 17th century, such as the "Takeshima Tosho Otodo" (1661), refer to the islands as Takeshima and describe fishing rights granted by the Tokugawa shogunate to the Oki Islands. Japan argues that these documents demonstrate historical control. However, the Korean side contends that Japanese references were limited to occasional use and not sovereign ownership. The 1905 incorporation of the islands into Shimane Prefecture is a critical point of contention, as Korea argues it was invalid due to the forced protectorate status.

19th Century and Early 20th Century

During the 19th century, both Korean and Japanese fishermen frequented the islands. Korean records from the 1800s describe seasonal stays on the islands for fishing and gathering seaweed. In 1900, the Korean Empire issued an ordinance that included Dokdo under the jurisdiction of Ulleungdo. However, Japan's victory in the Russo-Japanese War (1904-1905) shifted power dynamics. In 1905, Japan declared the islands as terra nullius and incorporated them into Shimane Prefecture. This act is disputed, as Korea was under Japanese protection and unable to protest independently. The incorporation was not publicized widely, which Korea argues indicates its irregular nature. For more details on historical documents, refer to the South Korean Ministry of Foreign Affairs' historical records.

20th Century and Post-War Era

Following Japan's defeat in World War II, the Allied powers defined Japanese territory under the San Francisco Peace Treaty of 1951. The treaty did not explicitly mention Dokdo/Takeshima, leaving its status ambiguous. In 1952, South Korean President Syngman Rhee unilaterally proclaimed the "Peace Line," claiming jurisdiction up to 200 nautical miles from the Korean coast, which included the islands. South Korea took physical control in 1954, establishing a lighthouse and a police garrison.

Japan protested these actions, and in 1965, the two countries signed the Treaty on Basic Relations, which normalized diplomatic relations but left the territorial dispute unresolved. Japan has repeatedly proposed submitting the dispute to the International Court of Justice (ICJ), but South Korea has consistently refused, maintaining that there is no territorial dispute.

Sovereignty Dispute

South Korea bases its claim on several principles:

  • Historic Continuity: Korea has exercised sovereignty over the islands since the 6th century, as evidenced by historical documents and maps.
  • Effective Control: Since 1954, South Korea has maintained continuous and peaceful occupation without any international opposition except from Japan.
  • Invalidity of Japan's 1905 Claim: The incorporation was part of Japan's imperial expansion, not recognized under international law.
  • Geographical Proximity: The islands are closer to Ulleungdo than to any Japanese island, supporting natural extension.

South Korea emphasizes that the issue is not a legal dispute but a matter of national territory, and therefore, does not require international arbitration. For an official statement, see the South Korean perspective on Dokdo.

Japan's claim is based on:

  • Historical Use: Japanese fishermen and merchants used the islands since the 17th century, and the government acknowledged them as terra nullius before 1905.
  • Official Incorporation: In 1905, the Japanese government formally designated the islands as part of Shimane Prefecture after confirming no other state had claimed them.
  • Post-War Treaties: Japan argues that the San Francisco Peace Treaty did not specify the islands as Korean, and that the UN Command's exclusion of the islands from its administration supports Japan's position.
  • Peaceful Resolution: Japan seeks resolution through the ICJ and has offered to abide by its decision, a proposal South Korea has rejected.

Japan's Ministry of Foreign Affairs publishes a series of pamphlets and maps to support its claim, including the "10 Issues of Takeshima" document. For more information, visit the Japanese Ministry of Foreign Affairs' Takeshima page.

International Law and Arbitration

International law provides frameworks for territorial disputes, including the principle of uti possidetis juris and the role of effective occupation. South Korea's continuous and peaceful occupation since 1954 strengthens its claim under the theory of prescriptive title. Japan's argument relies on its prior sovereignty and the lack of Korean protest in the early 20th century. The International Court of Justice has addressed similar disputes, such as the South China Sea arbitration, but each case is unique. Without South Korea's consent, the ICJ cannot adjudicate. Some scholars suggest that bilateral negotiation or a joint development zone could offer a solution.

Strategic and Economic Importance

Military and Geopolitical Significance

Dokdo/Takeshima sits in a strategically vital area of the Sea of Japan. It is located near major sea lanes that handle a significant portion of global trade, including energy supplies from the Middle East. Control of the islands allows for monitoring of ship traffic and airspace, which is critical for national security. South Korea uses the islands as a forward operating base for its coast guard, and the islands are frequently included in maritime exercises. For Japan, the islands are part of its territorial defense perimeter, and any South Korean military presence is seen as a provocation.

The dispute also impacts regional alliances. The United States, a key ally of both countries, maintains a delicate balance, officially not taking a position while encouraging dialogue. The dispute has hindered trilateral cooperation on issues like North Korea's missile threats and strengthening the alliance framework.

Economic Resources

The waters around Dokdo/Takeshima are among the most productive fishing areas in the region. Species like mackerel, squid, and pollock are harvested by both South Korean and Japanese fishing vessels. The abundance of seaweed (such as kelp) is also commercially important. The fishing industry in nearby Ulleungdo is particularly dependent on access to these waters. Additionally, there is potential for significant oil and natural gas reserves beneath the seabed. Both countries have conducted geological surveys, and the prospect of hydrocarbon exploitation adds economic urgency to the territorial claim.

Tourism to the islands is limited but symbolic. South Korea operates regular boat tours from Ulleungdo, allowing visitors to see the islands from a distance, but landing is restricted. The economic value is more about resource access than the land itself.

Exclusive Economic Zone Claims

The dispute is intrinsically linked to exclusive economic zone (EEZ) delimitation. Under the United Nations Convention on the Law of the Sea (UNCLOS), coastal states can claim up to 200 nautical miles of EEZ. South Korea and Japan have overlapping claims in the Sea of Japan, centered on Dokdo/Takeshima. The area is believed to contain fish stocks worth millions of dollars annually and potential oil and gas fields. Unresolved EEZ boundaries lead to conflicts over fishing rights, as seen in the arrest of fishing vessels. The dispute complicates maritime security, including search and rescue operations and military patrols.

Environmental and Ecological Significance

The Dokdo/Takeshima ecosystem is highlighted by its biodiversity. The islands serve as a crucial breeding ground for marine birds, including the black-tailed gull and the streaked shearwater. The surrounding waters support fish stocks, marine mammals, and a variety of invertebrates. South Korea has declared the area a Marine Protected Area (MPA) to conserve the natural environment. Ecological research is conducted jointly with other countries, but political tensions often limit cooperation. The environmental importance of the region underscores the need for sustainable management, regardless of the sovereignty dispute. For research on the region's ecology, see an academic study on the islands' ecology.

Current Status and International Implications

As of 2025, South Korea maintains full administrative control over Dokdo. A small police contingent of around 30 officers is stationed on the islands on a rotational basis. Civilian access is permitted with prior approval, and a regular ferry service operates from Ulleungdo. South Korea has built a landing pier, helicopter pad, lighthouse, and residential quarters on the islands. The Korean government also manages a museum and visitor center on Ulleungdo dedicated to Dokdo's history.

Recent Developments (2019-2025)

Recent years have seen heightened tensions. In 2019, Japan's imposition of export controls on key materials for South Korea's tech industry was widely seen as a retaliation for South Korea's Dokdo patrols and the Supreme Court ruling on forced labor. South Korea responded by considering the termination of the General Security of Military Information Agreement (GSOMIA) with Japan, though it later reversed. In 2023, South Korea conducted a major maritime exercise near Dokdo, prompting a strong protest from Japan. The same year, South Korea and the United States held joint drills near the islands, which Japan criticized. As of 2025, the dispute remains active, with both countries issuing diplomatic notes and maintaining their respective positions.

Internationally, the dispute has not been recognized as a legal case by any international court due to South Korea's refusal. The United Nations has not taken a stance. The dispute affects South Korea-Japan relations, which are already strained by historical issues such as wartime forced labor. Tensions over Dokdo/Takeshima have prevented broader regional cooperation, including a proposed East Asia security framework. The dispute also resonates in domestic politics, where leaders use it to rally nationalist support.

Under international law, the situation highlights the complexities of territorial disputes involving effective occupation, historical consolidation, and the interpretation of post-war treaties. The ICJ statute requires consent from both parties for jurisdiction, so no binding resolution is imminent. The dispute remains a staple of diplomatic discourse in Northeast Asia.

Looking Ahead

The Dokdo/Takeshima dispute is unlikely to be resolved in the near future. Both South Korea and Japan have hardened their positions, and public opinion in each country is strongly nationalistic. The physical geography of the islands, while small in area, gives them outsized symbolic and strategic value. Environmental cooperation could serve as a backchannel for dialogue, but political trust is low. Ultimately, the dispute underscores how historical narratives and geographic facts combine to shape contemporary international relations in Asia. Until a broader geopolitical shift occurs, Dokdo/Takeshima will remain a flashpoint for national pride and territorial integrity.