Table of Contents
The East Sea, internationally known as the Sea of Japan, was recently in the news after North Korea fired an unidentified projectile into the sea. Its strategic location makes it an important geographical and geopolitical region of Northeast Asia.
About East Sea
The East Sea is a semi-enclosed marginal sea of the western Pacific Ocean, located between the Asian mainland and the Japanese archipelago.

Countries Bordering the East Sea
The sea is bordered by:
- North Korea
- South Korea
- Japan
- Russia
Its location places it at the intersection of major geopolitical and maritime interests in Northeast Asia.
Major Basins
The East Sea has a complex underwater topography and contains three major deep-water basins:
- Japan Basin
- Yamato Basin
- Tsushima Basin
Important Straits
The East Sea is connected with surrounding water bodies through several important straits:
- Korea/Tsushima Strait: Connects the East Sea with the East China Sea.
- Tsugaru Strait: Connects the sea with the Pacific Ocean.
- La Pérouse (Soya) Strait: Provides a connection toward the Sea of Okhotsk.
- Tatar Strait: Located to the north, between mainland Russia and Sakhalin.
Ocean Currents
The Tsushima Current is a major warm current entering the East Sea from the south. Its interaction with colder waters influences the region’s marine ecosystems, fisheries and climate.
Strategic Importance of East Sea
1. Northeast Asian Security
The East Sea is strategically important because of its proximity to North Korea, South Korea, Japan and Russia. North Korean missile and military activities in the region frequently have wider security implications.
2. Russian Pacific Access
The sea is an important maritime space for Russia’s Far East and its broader access to the Pacific region.
3. Fisheries and Natural Resources
The interaction of different water masses creates productive marine environments supporting fisheries and biodiversity. The region also has potential natural gas and methane hydrate resources.
4. Dokdo/Takeshima Dispute
The maritime region is associated with the territorial dispute between South Korea and Japan over islands known as Dokdo in South Korea and Takeshima in Japan.
5. Naming Dispute
The terminology itself is politically sensitive. South Korea uses “East Sea,” while “Sea of Japan” is the internationally established name used in many international contexts. The two countries have differing positions on the naming of the sea.
East Sea Facts
| Feature | Key Fact |
|---|---|
| Type | Semi-enclosed marginal sea |
| Ocean | Western Pacific Ocean |
| Also known as | Sea of Japan |
| Location | Between Asian mainland and Japanese archipelago |
| Bordering countries | Japan, South Korea, North Korea, Russia |
| Major basins | Japan, Yamato and Tsushima |
| Major current | Tsushima Current |
| Important straits | Korea/Tsushima, Tsugaru, La Pérouse and Tatar |
| Key geopolitical issues | North Korean security, Dokdo/Takeshima dispute and naming disagreement |


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