Context
On 20 September 2026, North Korea launched two ballistic missiles from its east coast towards the Sea of Japan within about three hours. Japan assessed that both fell outside its Exclusive Economic Zone.
The launches again highlighted the geopolitical importance of this semi-enclosed sea situated between Japan, the Korean Peninsula and the Russian Far East.
About the Sea of Japan
The Sea of Japan, called the East Sea in South Korea, is a marginal sea of the western Pacific Ocean.
It is bounded by:
- Russia and Sakhalin Island in the north;
- North Korea and South Korea in the west;
- the Japanese islands of Hokkaido, Honshu and Kyushu in the east and south.
The Japanese archipelago separates it from the open Pacific, giving the sea a relatively semi-enclosed character.
Important Connections
The sea communicates with surrounding water bodies through narrow straits:
- Tsushima/Korea Strait → East China Sea;
- Tsugaru Strait → Pacific Ocean;
- La Pérouse/Soya Strait → Sea of Okhotsk;
- Tatar Strait → waters north of Sakhalin.
These narrow passages strongly influence its water circulation, maritime access and strategic geography.
Important Physical Features
Warm-Water Influence
The Tsushima Warm Current, a branch of the Kuroshio system, enters through the Tsushima Strait and influences the climate and marine conditions along Japan’s western coast.
Low Tidal Range
Because the sea is connected with the Pacific mainly through narrow straits, tidal variations are generally smaller than along Japan’s open Pacific coast.
Rich Fisheries
The interaction of warm and cold waters supports productive marine ecosystems and important fishing grounds.
FAQs
Q1. Where is the Sea of Japan located?
Between the Japanese archipelago, Korean Peninsula and Russian Far East.
Q2. Which strait connects it with the Pacific Ocean?
The Tsugaru Strait.
Q3. Which strait connects it with the East China Sea?
The Tsushima/Korea Strait.
Q4. What is another name used for the Sea of Japan?
South Korea commonly calls it the East Sea.
Q5. Why is it strategically important?
Its location links the security interests of Japan, the Koreas and Russia and places it close to major Northeast Asian military and maritime routes.
