What?

Japan has two major ongoing territorial disputes with its neighbors: one with Russia over the southern Kuril Islands (known as the Northern Territories in Japan), and another with South Korea over the Liancourt Rocks (called Dokdo in South Korea and Takeshima in Japan). These disputes stem from historical events, particularly World War II and colonial legacies, and they prevent full normalization of relations in some cases.

Dispute with Russia: The Kuril Islands / Northern Territories

• What is disputed? The four southernmost islands in the Kuril chain: Iturup (Etorofu), Kunashir (Kunashiri), Shikotan, and the Habomai group (sometimes collectively called the Northern Territories by Japan). These islands are currently administered by Russia as part of Sakhalin Oblast, but Japan claims them as inherent territory.
• Historical background
  • Japan controlled the islands in the 19th century under treaties like the 1855 Treaty of Shimoda.
  • At the end of World War II (1945), the Soviet Union occupied them after Japan's surrender.
  • The 1951 San Francisco Peace Treaty ended Japan's WWII claims but did not explicitly assign the islands, leaving the issue unresolved.
  • No formal peace treaty has ever been signed between Japan and Russia (or the Soviet Union) post-WWII due to this dispute.
• Current status
  • Relations are at a low point: Kremlin spokesman Dmitry Peskov stated on February 20, 2026, that bilateral ties have been "reduced to zero" due to Japan's "unfriendly stance" (mainly sanctions over Russia's Ukraine invasion).
  • No ongoing dialogue or negotiations on a peace treaty exist.
  • Japan's new Prime Minister Sanae Takaichi reiterated in parliament her intent to resolve the territorial issue and conclude a peace treaty, but Russia dismissed it as impossible without a major shift in relations.
  • The dispute remains frozen, with Russia firmly controlling the islands and Japan viewing them as illegally occupied.
• Why it matters It blocks a formal peace treaty, limits economic cooperation, and adds to regional tensions in the Asia-Pacific, especially amid Russia's closer ties with China.

Dispute with South Korea: The Liancourt Rocks / Dokdo / Takeshima

• What is disputed? A small group of rocky islets (about 0.18 km²) in the Sea of Japan, plus surrounding waters. South Korea administers and controls them (with a small police presence and lighthouse), while Japan claims sovereignty.
• Historical background
  • The dispute dates back centuries, with competing claims from ancient maps and records.
  • Japan incorporated the rocks in 1905 (during its colonial expansion toward Korea).
  • After Japan's defeat in WWII, South Korea asserted control in the 1950s (under President Syngman Rhee's "Peace Line"), and has maintained effective control ever since.
  • The 1965 Japan-South Korea normalization treaty did not resolve the issue.
• Current status 
  • Tensions flared recently: On February 22, 2026, South Korea strongly protested Japan's annual "Takeshima Day" event in Shimane Prefecture (commemorating Japan's claim), calling it an "unjust assertion of sovereignty."
  • South Korea's foreign ministry summoned a Japanese diplomat, urged Japan to abolish the ceremony, and reiterated that Dokdo is "clearly South Korea's sovereign territory historically, geographically, and under international law."
  • Japan continues to assert the islands as its territory in official documents and protests South Korea's control as "illegal occupation."
  • South Korea rejects third-party arbitration (e.g., International Court of Justice), viewing it as unnecessary since it exercises control.
• Why it matters The islets have limited economic value (fishing rights, potential seabed resources), but they carry huge symbolic weight. For South Korea, Dokdo represents resistance to Japan's colonial past (1910–1945). For Japan, it ties into broader territorial assertions. Periodic flare-ups strain bilateral ties despite shared interests (e.g., U.S. alliances against North Korea and China).

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