Prime Minister Shinzo Abe's recent summit with Russian President Vladimir Putin has thrown fresh light on the political, security and other factors complicating efforts to solve the two countries' decades-long territorial dispute.

The two leaders, meeting in Japan, agreed on joint economic activities on disputed islets controlled by Russia off Hokkaido, saying it would be the first step toward building a relationship of trust and resolving the territorial spat.

For Abe, regaining ownership of the islands — Etorofu, Kunashiri, Shikotan and the Habomai islet group — is part of his efforts to tackle what he sees as unresolved issues stemming from World War II, which also include revising the U.S.-written postwar Constitution. As well as hoping to accommodate former islanders' desire to return home, he sees a solution to the dispute, like other existing territorial issues with China and South Korea, as a matter of national interest, analysts say.