This article examines the dispute over whaling from the perspective of Japan, a country fiercely protective of its right to whale. It outlines the key roles played by transnational environmental actors in defining and instituting an international norm of anti-whaling, symbolized in the passage of the moratorium on commercial whaling in 1982. This signaled a rejection of previously held attitudes towards the use of whales as natural resources and the embracing of a protectionist, hands-off approach. Support for this new stance, however, was not forthcoming from pro-whaling states Japan, Norway and Iceland. By analyzing Japan's original objection to the moratorium, its later compliance, and then its commitment to the resumption of limited commercial whaling, this article outlines the principles that underpin Japan's whaling policy. While the Japanese government views the whaling dispute as a threat to resource security and a danger to inter-state respect for differences in custom and cuisine, the need to be perceived as a responsible member of international society exercises a major influence on the formation of Japan's whaling policy, conditioning its rule compliance and prohibiting the independent action pursued by other pro-whaling states. Recent developments in the whaling dispute, however, may be enough to dislodge Japan's commitment to the moratorium, which would impact upon the legitimacy of the International Whaling Commission.