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Sea of Japan vs. East Sea

Old map of the "Mer de Corée", which is nowadays widely called the "Sea of Japan"

"Sea of Japan", "East Sea" or both? Map: Wikimedia Commons.

With 16 history professors, diplomats and maritime officials, South Korea sent the third-largest delegation to the 18th International Hydrographic Conference, in Monte Carlo, in April this year. In this case, however, strength did not lie in numbers:  At the summit, the International Hydrographic Organization (IHO)rejected Korea’s request to use the name “East Sea” alongside the established “Sea of Japan” to designate the body of water that lies between the Japanese Archipelago and the Korean Peninsula. Instead, it was decided that the exclusive use of the name “Sea of Japan” would continue through 2017, when the next conference is set to take place.

For twenty years, Japan and South Korea have been involved in a diplomatic spat over the name of the body of water in question – which borders Japan, North Korea, Russia and South Korea – and the dispute remains a source of continued frustration for the Koreans. So far, the naming controversy has not led to a direct military clash between the two countries, but, with Japan continuing to favor the status quo, Korea seems to be stepping up efforts to achieve a name change (either to its preferred option, or to the concurrent use of the two terms), thus politicizing the technical question of maritime name designations.

Terms used to refer to the body of water varied before the 18th century but “Sea of Japan” became more widely used in the 19th and 20th centuries due to Japan’s rise, in the Meiji period, to regional and then world power status.  Ever since its inclusion, however, in the first authoritative text on the names of seas and oceans – the “Limits of Oceans and Seas,” published by the IHO in 1929 – the use of the name “Sea of Japan” has become increasingly widespread.

In fact, it was only as recently as 1992 that the South Korean government began to formally object to the name “Sea of Japan” – raising the issue at that year’s sixth UN Conference on the Standardization of Geographical Names. Since then, Korea has continued to bring the issue up at international conferences and meetings of the IHO. Japan, in turn, now feels pressed to repudiate Korea’s claims.

In order to substantiate their respective arguments, both sides point to old maps as evidence that the use of their respective terms has a sounder basis in history. Korea, for example, postulates that the term “East Sea” first appeared in a historical document dating back to as early as 59 B.C., which it considers  proof that the name “East Sea” was used 1,700 years before the first appearance of the name “Sea of Japan.” Korea further argues that the name “Sea of Japan” is a legacy of Japan’s 1910-1945 colonial rule of the Korean Peninsula and, as such, is unacceptable to the Korean people (to which the Japanese government replies that “Sea of Japan” is the most widely accepted term throughout the world, pointing out that it was used internationally long before Japan colonized Korea.)

But Korea and Japan have not  only dug out historical maps and documents to support their arguments, they also point to what they claim is geographical evidence.  According to the Koreans, “East Sea” makes sense because the body of water is located east of Korea (but west of Japan and to the south of Russia), whereas, for the Japanese, the name “Sea of Japan” is more appropriate because, as they argue, without the Japanese Archipelago, the sea would not exist. Japan also claims that the designation “East Sea” is ambiguous because it fails to indicate a single place (the East China Sea is referred to as “East Sea” by both the Chinese and Vietnamese; and the Baltic Sea is known as “East Sea” in various European countries).

To further back up their respective claims, both countries have conducted studies – with some interesting results.  Korea, for example, claims that 66% of historical maps in the US Library of Congress use the term “East Sea.”  Incidentally, Japan insists that  that 77%  of the very same maps use “Sea of Japan”.

To reach their respective objectives both sides have adopted strategies characterized by intense lobbying. Since the late 1990’s, Korean activists have been asking map makers, travel guides and geography websites to use the name “East Sea” along with “Sea of Japan.”  (The ISN, for instance, received a request from a media marketing firm on behalf of the Korean Consulate General in New York regarding the issue.) And indeed, several newspapers such as Le Monde and Le Figaro, as well as dictionaries and encyclopedias like Larousse, have started including the term “East Sea.” However, even though the campaign seems to be gaining traction – with a petition on the White House website in support of the “East Sea” designation drawing more than 100,000 signatures — important Korean allies like the US continue to use “Sea of Japan” exclusively.

And although the name does not affect the shared jurisdiction of the water itself, some Korean “East Sea” supporters maintain that exclusive use of  ”Sea of Japan” could actually undermine Korea’s ownership of Dokdo, a group of small islets that have been under Korean administration since the end of World War 2. In Japan, where Dokdo is referred to as Takeshima, claims to the islets have resurfaced after the end of the Cold War.

In the end, however, at the root of the controversy are not issues of national security or economic interest but of national pride and memory.  (On the Korean side, for instance, supporters of the “East Sea” designation go so far as to argue that the name is deeply rooted in the lives of the Korean people, and point out that the Korean national anthem itself refers to the “East Sea.”)

In the current politicized climate, it therefore seems unlikely that the warring parties will find consensus on what to call the body of water – at least not until 2017, when the debate is set to re-ignite at the next IHO summit.


For further information on the topic, please view the following publications from our partners:

Japan-Korea Relations and the Tokdo/Takeshima Dispute

Korea’s Elections and the KORUS FTA

Trilaterale Kooperation zwischen China, Japan und Südkorea

For more information on issues and events that shape our world please visit the ISN’s Security Watch and Editorial Plan.

One Response to “Sea of Japan vs. East Sea”

  1. To Whom It May Concern

    Firstly, I would like to show my respect for your managing this valuable website My name is jiheon seo. I am a student and a member of the Voluntary Agency Network of Korea (VANK) in Korea. VANK is a non-governmental volunteer organization, composed of students ranging from elementary school to college and adults who wish to tell correct information about Korea to foreign textbooks and publishing companies. I read this news and I want to send some information about east sea. For 2000 years the name of this body of water has been the East Sea. Korea’s oldest history book, ‘The histroy of Three Kingdoms’ records that the name East Sea had been in use since 37 B.C. The name East sea was introduced to the Europeans as the Korean peninsula and the Japanese archipelago began to appear on world maps following the worldwide voyages of discovery in the 16th century. Untill the 19th century, the sea area was variously called, the sea of korea, the eastern sea, the oriental sea,and the sea of japan.
    However, japanese infulence in East Asia began to rise rapidly in the 19th century, and in 1910,japan annexed Korea. At that time, Japan try to convert local geographical names to Japanese. Against this background, the first edition of Limist of oceans and seas published by IHO in 1929 used only the name Japan Sea. Korea has made continuous efforts to restore the name East Sea for decades. Resoultuins adopted by the UNCSGN and the IHO recommend that when countries haring a given geographical feature fail to agree on a common name, competing names should be concurently used. Therefore we sincerely hope worldwide will understand the relavant facts and historical background of the matter and I hope this real facts would be helped for you . Above all, I really appreciate for you to read my long letter.