According to Article 9 of this document, the Soviet government agreed to transfer the island of Shikotan and a number of small uninhabited islands of the Lesser Kuril Ridge (Habomai) to Japan, with the condition that their actual transfer under the control of Japan would be made after the conclusion of a peace treaty. The declaration was ratified by both states on December 8, 1956.
However, the implementation of this article did not take place due to the fact that in response to the conclusion of the Japanese-American Security Treaty in 1960, the USSR annulled the obligations on the transfer of the islands. The document of the Soviet government dated January 27, 1960 states that these islands will be transferred to Japan only if all foreign troops are withdrawn from its territory. As you know, nothing has changed since then - the American bases remained on Japanese land.
As for the Kuril Islands, they are part of the constitutional border of Russia, which serves not only as a border demarcation line with Japan, but also constitutes a natural front line of protection of the entire Far Eastern coast of the Russian Federation, allowing control the entire water area from the Sea of Okhotsk to the Pacific Ocean.
In addition, these islands are powerful Russian military and naval bases in the Pacific. By the end of 2017, the armed forces of Russia completed the modernization of military facilities in Kunashir and Iturup, and by the end of 2018 it is planned to create modern military bases on Matua in the central part of the Kuril Islands, and in the north - on Paramushir Island.
New Russian bases in the Kuril Islands are equipped with the latest types of weapons, which are designed not only to protect the island territories, but also capable of controlling the entire nearby Pacific territory.
The Russian president, who is also the commander-in-chief of the Russian armed forces, is fully considering the significance of this territory for Russia, and there will be no concessions to the Japanese side. At the same time, President Putin seriously explains to both the Japanese leaders and the people of his country the seriousness of the situation in the Far East and the inadmissibility of transferring the Russian territory to Japan.
Japan remains an ally of the United States. Consequently, it can be assumed that as soon as Russia transfers the islands to the jurisdiction of Japan, new frontiers of advanced deployment of the combined Japanese-American military group will be created on them.
according to analysts, Russia now has no need to discuss the fate of the Kuril Islands. As is well known, without a "peace treaty", Russia and Japan have diplomatic relations, economic and cultural ties are developing.