The Kuril Islands may be of strategic importance to Russia, but they are of ethical importance to the wider world, as a litmus test of when societal development will finally have moved Russia beyond Stalin's "might is right" ethos. They should also be of strategic economic importance to Russia, seeing as their continued occupation hinders Japanese investment in Russia's Far East. The Kuriles are Japanese territory, occupied by force by Stalin literally days before the end of WW2. Russian holding of the Kuriles works the same kind of international disadvantage to Moscow as its occupation of the Baltics used to.

At this time Kuriles belong to Russia, this hold a lot of mineral deposit. To give Island to Japan, will destroy Russia as a country, a lot of other countries will claims land or Island from Russia based on history. If the Japanese not investing in Russia far East, other countries will invest at the end, the loser is the Japanese. If Russia give the Kuriles to Japan, Russia will be the loser. Look at Alaska, Georgia, Estonia and all other lands Russia lost recently. Russia should never give or sale any land. Open Kuriles up allow any country to invest but never give Russia ownership.

Marzipan, you really need to read a (honest) history book. The Japanese launched war against Tsarist Russia in 1904 to grab territory, a continuation of the Imperial Japanese push into China and ongoing domination of Korea. Russia lost badly, and was forced to yield its access to Port Arthur, and lost the southern half of Sakhalin Island. The point here is that the Japanese unilaterally abrogated the Treaty of Saint Peterberg 1875, where Tsarist Russia recognised Japanese soverignty over the Kurils (and withdrew its colonies) in exchange for Japanese recognition of Russia rights over Sakhalin. Japanese agression negated the treaty, and it took 40 years before the Soviets could reassert their claims. The morale of this story is that if your commit agression against your neighbours, and then lose, the loss of territory is a real possibility. Germany has permanently lost sovereignty over her traditional eastern baltic territories, and you don't hear Angela Merkel whining constantly and demanding the return of Danzig (now Gdansk) and Pomeranian in Western Poland...