Korea has lodged a formal protest with the U.S. government for ignoring its request that it use both “East Sea” and “Sea of Japan” in calling the body of water between Korea and Japan. The East Sea is Korea’s preferred name for the maritime area.

According to reports, the U.S. government has confirmed its policy of calling the disputed area the Sea of Japan, on the grounds that it is the standard name endorsed by the U.S. Board on Geographic Names. Washington is against using both names because it has a single-name policy in designating seas and oceans.

Washington has reportedly sent a formal letter to this effect to the International Hydrographic Organization, an intergovernmental organization that publishes “Limits of Oceans and Seas,” the global authority on the names and locations of seas and oceans.

It is disappointing that the U.S. government has refused to acknowledge Seoul’s historically justified claim regarding the sea name. The East Sea is a much older name than the Sea of Japan. Korea’s use of the appellation can be traced to maps drawn in the 16th century, while the Sea of Japan is a name Japan created in the early 20th century during its colonial rule of Korea.

The Sea of Japan began to be used internationally after the IHO published its first edition of the Limits of Oceans and Seas in 1929. The name was used in the second and third editions of the publication issued in 1937 and 1953, respectively. Korea could not participate in the IHO conferences on the first two editions because it was under Japan’s colonial rule and for the third edition because of the Korean War.

Seen from this historical perspective, it would be grossly unfair for Korea if the international community only recognizes the Sea of Japan. To deal with such a problem, IHO Technical Resolution A 4.2.6 allows, in the case of dispute, for the two names to be put side by side. Following this resolution, the channel separating Great Britain from France is called in two ways ― the English Channel as preferred by Great Britain and la Manche, its French name.

The IHO has another solution for a disputed area ― simply not to identify the place. Hence, in its 2000 conference, the IHO proposed to leave the disputed area between Korea and Japan unidentified until a compromise is reached. This proposal was not adopted due to Japan’s opposition.

These examples illustrate that Washington’s insistence on the single-name policy makes little sense. This means Korea needs to press the U.S. and other countries to refer to the disputed area as the East Sea as well as the Sea of Japan.

Korea set out to promote the name of the East Sea in 1992. According to a government survey, 28 percent of maps around the world now put the two names side by side. This is by no means a small achievement. But the government needs to double down on its promotion efforts.