Among Japan's territorial disputes, its claim on Russia's southern Kuril Islands is less widely reported that its frictions with China in the East China sea.
But with the row reignited by Russian President Dimitry Medvedev's historic visit to the islands, Pacific affairs analyst Ralph Cossa, who heads the Pacific Forum think tank, explains here for BBC World Service that it is unlikely to be resolved any time soon.
This dispute really goes back to the closing days of World War II when the Russians moved into the southern islands, which the Japanese had owned, and seized them as war spoils.
Under the San Francisco Treaty, Japan had to cede the islands but it was not specified that they would be given to the Soviet Union. The US, in fact, supports Japan's claims to the islands but the Russians have made it clear they have no intention of handing them back.
All the Japanese people who had lived on the islands were expelled by the Russians. Part of the dispute is history and national pride. The Japanese feel that this has traditionally been their territory. There are still some people who have property there that they want to reclaim. There are also some very rich fishing grounds and there are also some underwater resources that people want to exploit.
From the Russian standpoint, the islands are also part of the access to the Sea of Okhotsk, which is the main reason they want to keep them in their hands.
This dispute will not resolve itself. It is one of those rows that will last for a long time. Once or twice in recent decades, there were hints that the Russians might cut a deal with the Japanese, keeping the two northern islands and giving the Japanese the southern two, in return for a large sum of money.
The Japanese refused to do that in those days. They would probably take the deal now but the Russians are no longer offering.
These islands are no place you would want to go for a vacation. It is pretty cold and nasty up there and the people who live there are primarily fishermen and Russian border guards.
I would not compare this at all with the spat with the Chinese. In fact it may be useful to watch the Japanese behaviour toward Russia and compare it with the Chinese behaviour toward Japan over the Senkaku/Diaoyu Islands.
The Japanese are a little bit more mature, a little bit more diplomatic, a little bit more of a "normal" nation than the Chinese who have behaved rather badly over the Senkaku/Diaoyu issue.