Northeast Asian History Network

As defined by international law, an “island” includes 12 nautical miles ofterritorial waters and 200 nautical miles of exclusive economic zone, or EEZ. EEZ is defined as 200 nautical miles from the baseline (mean low-water mark) and excludes the territorial waters. Although foreign ships and aircraft are allowed innocent passage through the EEZ, resource development and fishing activities are limited.
Both South Korea and Japan proclaimed 200 nautical miles of EEZ in 1996. Shortly after, it was discovered that certain EEZ areas were overlapping. As territorial disputes arose, it was clear that maritime boundaries had to be clarified between the two countries. Thus, a fisheries agreement was signed between South Korea and Japan. This agreement applies to the EEZ of both countries. The territorial waters around Dokdo are treated as Korean territory, therefore, they are not considered to be anintermediate zone of the EEZ. If the EEZ boundaries of the two countries are demarcated in the future, the provisional nature of the intermediate zone will be eliminated.


“East Sea” is a name that Koreans have been using for more than 2,000 years. This fact can be verified in the following historical sources and maps: “King Dongmyeong of Koguryo” section (37 BCE) and the “Epitaph of King Gwanggaeto” (414) from History of the Three Kingdoms, “Map of the Eight Provinces” from New and Expanded Complete Conspectus of the Territory of the Eastern Country (1531), and “Map of Korea” from Map of the Territory (late eighteenth century). Until the end of the nineteenth century, Japanese maps labeled the East Sea as Sea of Joseon or Sea of Japan. In Western maps, a variety of names were used, including Sea of China, Manchuria Sea, Eastern Sea, East Sea, Sea of Korea, Sea of Japan, and Tartar Sea. However, from the late nineteenth century and throughout the twentieth century, “Sea of Japan” was generally accepted among the international community as Japan’s international influence had increased.
After joining the United Nations in 1991, the South Korean government has claimed during the United Nations Conference on the Standardization of Geographical Names (UNCSGN) in 1992 that the sole nomination of the East Sea as the “Sea of Japan” was unreasonable. The international community has advised that when a naming dispute arises between two countries that both names are to be used until an agreement is reached. South Korea has claimed that both “East Sea” and “Sea of Japan” be used, but Japan has taken the position that any name other than “Sea of Japan” for the region is unacceptable.


The South Korean government and private organizations have endeavored to spread the usage of “East Sea” in the international community. As a result, recent world maps have begun to use both names for the area, labeling it as “East Sea/Sea of Japan.”
According to surveys conducted by the Japanese Ministry of Foreign Affairs and the Korean Ministry of Foreign Affairs and Trade, the use of both names has been steadily increasing: in 2000 (Japan) 2.8%, in 2005 (Japan) 10.8%, in 2007 (Korea) 23.8%, and in 2009 (Korea) 28.07%.