When Hatoyama Yukio became the first Democratic Party of Japan (DPJ) prime minister in 2009 and began advocating for an East Asian Community (EAC), it looked like a bright moment in China-Japan relations and perhaps for all Northeast Asia. However, Hatoyama’s vision of EAC, based on the idea of regional economic cooperation and integration as well as the idealistic philosophy of "yu-ai" or "fraternity" never materialized. His idealism, sadly, was thwarted by the logic of realism and geopolitics. Indeed, in just three years, China-Japan relations seem to have gone "back to the future," trapped in a simmering security dilemma characterized by the repeated flare-up of territorial disputes, increasing strategic distrust, and the spillover of political disputes into the economic arena. "Cold politics, warm economics" (zhengleng jingre, or seirei keinetsu) – a phrase coined to describe the close economic ties between China and Japan despite political spats over sensitive issues such as the Yasukuni Shrine and history textbooks – has been replaced by the depressing "cold politics and economics" (zhengleng jingleng, or seirei keikan).