Introduction : subnational governments as international actors --Tokyo, Moscow and the disputed islands -- Determinants of Russian and Japanese subnational diplomacy and the rise of the 'Sakhalin factor' -- Hokkaido-Sakhalin transnational relations -- The Sakhalin political elite and the South Kuril Islands -- Sakhalin public opinion and the South Kuril Islands -- Sakhalin's commercial environment and local trade -- Conclusion : Yeltsin, Putin and the 'Sakhalin factor'.