Japan is experiencing a new dynamism, consequence of a decade of deep reforms: affirmation of the economic leadership, prevalence of merit among age, increased flexibility, liberalization of numerous sectors (energy, financial activities) or privatization (universities, postal service). The excellence of Japan’s economic insertion in the region contrasts with its difficulties to define pacified security and political relations. To avoid genuine “realpolitik” or “neo-mercantilist” temptations, Japan has to develop dialogue, measures of confidence and regional institutions. Europeans shall not underestimate Japan’s influence or the importance of their interests in North-East Asia.