Meeting in Singapore on Wednesday, Prime Minister Shinzo Abe and Russian President Vladimir Putin agreed to accelerate peace treaty negotiations on the basis of the 1956 joint declaration. This has generated excitement since the document raises the possibility of Russia transferring two islands to Japan following the conclusion of a peace treaty. However, while debate in Tokyo focuses on whether Abe is right to prioritize the return of just two of the four disputed islands, attention should be given to the conditions that Russia will apply to even a two-island deal.

As with Japan's Constitution, it is Article 9 of the 1956 joint declaration that is the most noteworthy. This states that the Soviet Union "agrees to transfer to Japan the Habomai Islands and the island of Shikotan," with "the actual transfer ... to take place after the conclusion of a Peace Treaty." Although Habomai is actually a group of islets, it is commonly referred to as a single island for convenience.

Japan rejected the Soviet offer in 1956 as insufficient, yet Abe's decision to return to the joint declaration is not unprecedented. In particular, the Irkutsk statement that was issued by Prime Minister Yoshiro Mori and President Vladimir Putin in March 2001 also agreed to further peace treaty negotiations on the basis of this and other documents.