Russo-Japanese territorial dispute

The dispute concerns four islands off Hokkaido that Japan calls the Northern Territories (Hoppō Ryōdo) and Russia administers as part of the southern Kuril Islands: Etorofu/Iturup, Kunashiri/Kunashir, Shikotan, and the Habomai islets. Soviet forces occupied the islands in the closing days of World War II in late August and early September 1945, and the roughly 17,000 Japanese residents were subsequently expelled.

The legal arguments draw on overlapping instruments. Japan points to the 1855 Treaty of Shimoda, which placed the border between Etorofu and Urup, and argues the four islands were never part of the Kuril chain that Japan renounced under Article 2(c) of the 1951 San Francisco Peace Treaty. The Soviet Union did not sign that treaty. Moscow has historically cited the 1945 Yalta Agreement and the outcome of the war as the basis for its sovereignty.

The 1956 Soviet–Japanese Joint Declaration ended the state of war and restored diplomatic relations; in it, Moscow agreed to transfer Shikotan and the Habomais to Japan after a peace treaty was concluded. No such treaty has been signed. Negotiations revived under Prime Minister Shinzo Abe and President Vladimir Putin, who met more than 20 times between 2013 and 2020 and explored joint economic activity on the islands, but produced no breakthrough.

After Japan joined Western sanctions following Russia's February 2022 invasion of Ukraine, Moscow suspended peace-treaty talks in March 2022 and withdrew from visa-free exchange arrangements for former Japanese residents. Russia has since reinforced its military presence on the islands, including reported deployments of coastal-defence systems.

The dispute matters beyond bilateral relations: it shapes fisheries access in the Sea of Okhotsk, complicates Japan's Indo-Pacific alignment, and is frequently invoked as a precedent or counter-precedent in discussions of other unresolved post-1945 territorial questions in East Asia.