Japan and China present two interesting cases of reforestation policies implemented consecutively to address severe environmental damage for quite similar reasons, at different periods of their history. In parallel to their competition in different fields such as diplomacy and strategy, the two countries are also currently engaged in an increasing dialogue and cooperation on projects related to the protection of the environment and reforestation programs in China, not only as a consequence of a common perception of environmental security expanded to the regional level, but also depending on the political dialogue between the two countries. This article presents the legacy of Japan and China in reforestation, introduces the cooperation between the two countries as well as the exportation of their rivalry in other regions, and questions the relevance of a “green detente” in the case of the Tokyo-Beijing environmental dialogue as a factor of regional integration.