After the Second World War, all the Kurile Islands were incorporated into the Soviet Union. However, the ownership of islands of Iturup, Kunashir, Shikotan and the Habomai group of islands claimed by Japan, which considers these islands were occupied in violation of the legal norms. Russia argues that its sovereignty over the South Kuril Islands is absolutely legal and there is no doubt and discussion, as well as states that do not recognize the very existence of the territorial dispute with Japan. The problem of the South Kuril Islands accessories is the main obstacle to the full settlement of the Russian-Japanese relations and the signing of a peace treaty.
I recall that in 1956 the Soviet Union proposed to solve this problem. October 19, 1956 the Soviet Union and Japan signed the Moscow Declaration. The declaration ended the state of war, restored diplomatic relations between the two countries, as well as the guaranteed transfer to Japan the islands of Habomai and Shikotan (after the conclusion of a peace treaty). Later, however, the Japanese side refused to sign a peace treaty. US threatened that if Japan refuses to claim the islands of Kunashir and Iturup, the US will not return to the island of Ryukyu Okinawa (which is based on Article 3 of the San Francisco Peace Treaty was then under US control).
January 19, 1960, Japan signed the "Agreement on cooperation and security" with the US, thus extending the "security pact" (signed on September 8, 1951). The pact which allowed a stay of American troops on Japanese territory. January 27, 1960 the USSR informed that this agreement is directed against the Soviet Union and China, however, the Soviet government refused to consider the transfer of the islands of Japan (since it will increase the area used by US troops).
It seems strange that in Japan there are US troops. After all, the US military bombed Hiroshima and Nagasaki nuclear bombs.
I'm not a politician, but a high degree of confidence I can say that for the return of the islands (in theory) you need to fulfill the conditions
- On the territory of Japan need to remove all US military bases
- Japan should stop all relations with NATO
- Japan must guarantee in writing that Japan will not interfere with the passage of Russian warships through the straits, which does not freeze in winter
- Japan must promise to sign a peace treaty between Russia and Japan
Even though it does not guarantee the transfer of the islands of Japan. The problem is that the Russian people would be against the transfer, as Japan's policy is not friendly to the Soviet Union and Russia.