World War II Database

The Kurile Islands stretched from the Japanese home islands northward toward the Kamchatka Peninsula in Russia. Through the WW2-era, Japan controlled several southern islands in the Kurile Islands chain, while Russian settlements and military garrisons dotted the rest. In Aug 1945, the Soviet Union tore up the Soviet-Japanese Neutrality Pact of 1941 (which was in effect until at least Apr 1946) and took control of all the Kuriles. All Japanese nationals were deported back to the Japanese home islands by 1946. The 1951 San Francisco Peace Treaty stated that Japan must give up all its claims in the island chain, but the treaty failed to explicitly grant sovereignty of these islands to the Soviet Union. Furthermore, Japan argued that some of the islands were not part of the Kurile Islands chain, thus Russia had even less legal status for its continued occupation of those places. The state of war between the Soviet Union and Japan ended with the Soviet-Japanese Joint Declaration of 1956, but disputes over the islands of Iturup (Japanese: Etorofu), Kunashir (Japanese: Kunashiri), Shikotan, and the Habomai archipelago would continue, preventing the two nations from signing a formal peace treaty to end the very brief conflict between Russia (then a constituent country within the Soviet Union) and Japan. On 22 Nov 2019, Japanese Foreign Minister Toshimitsu Motegi and Russian Foreign Minister Sergei Lavrov agreed on a mid-Dec meeting in Russia to continue the discussion on this territorial dispute.

For more information:
Reuters: Japan foreign minister to visit Russia to discuss formal WWII treaty
WW2DB: Manchurian Strategic Offensive