Top Soviet officials were aware that the lack of a reference in the 1951 San Francisco Peace Treaty to the sovereignty of islands seized from Japan in the closing days of World War II could be exploited in postwar negotiations with Tokyo, declassified documents obtained by Kyodo News have shown.
Under the treaty signed by Japan and 48 other nations, Tokyo gave up territories it had seized, such as Taiwan, the Korean Peninsula and southern Sakhalin. The Soviet Union did not sign the treaty, which was implemented in 1952 to end the Allied postwar occupation of Japan.
The documents revealed Sunday refer to the Communist Party's strategies for negotiations launched in June 1955 with Japan. They show that Moscow decided to demand Tokyo's recognition of Soviet sovereignty over the seized islands, which are still at the heart of the current Japan-Russia talks toward a peace treaty, because the San Francisco treaty did not back Moscow's territorial claim.
A joint declaration signed by Japan and Russia in 1956 ended the state of war, but a peace treaty has not yet been signed.
Russia has continued to demand that Japan accept the outcome of the war and recognize Russia's sovereignty over the islands off Hokkaido, called the Northern Territories in Japan and Southern Kurils in Russia.
Japan maintains that the islands have been illegally occupied by Russia since they were seized by the Soviet Union after Tokyo's surrender in the war, in 1945.
Prime Minister Shinzo Abe and Russian President Vladimir Putin agreed in November to step up talks on the basis of the 1956 declaration, which mentions the transfer of the smaller two of the four islands following the conclusion of a peace treaty, but little progress has been made since.