Long considered as an economic giant and a political dwarf, Japan begins to solve this paradox by acquiring a political weight on the international scene. Its diplomacy remains non-assertive and its military role limited. But it has an increasing influence on the structure of the world economy by the size of its GNP, the composition and spread of its external economy and its capital ftows, and by the impact of its industrial policy on the international division of labour. The growing macroeconomic and financial interdependence between the US and Japan has an incidence on defence high technology and on the transfert of resources to the Third World. Japan's new status as a world power is acknowledged even by Gorbachov's « Eastern » policy. Japan's case weakens the assumption of the realist paradigm of international relations theory that power and interdependence are incompatible.