This paper is to present a framework to analyse international relations regarding protection and exploitation of an endangered species. The question of how to balance conservation and consumption in order to maintain the sustainability of resources and nature is not only the central challenge of conservation ecology, but also an international political and economic issue that frequently leads to confrontation between countries. In relation to whales, for example, Japan has long been subjected to criticism by anti-whaling countries such as the United States and Australia, and has faced off against them on the international stage. And, more recently, similar confrontations have begun to appear in relation to tuna and eel. It has been highlighted in recent years that Pacific Bluefin Tuna are becoming endangered, and there is considerable national and international concern with regard to their resource management. This paper first obtains an implication about the course of events that led to the fishing ban. The implication is applied to the case of Pacific Bluefin Tuna. Pacific Bluefin Tuna and the whaling issue reveals points of commonality. The conclusion is that history of the whaling issue implies that Japan will lose the support not only of countries opposed to fishing but also of neutral countries, if Tokyo continues to adopt policies which make light of resource conservation. Even a total ban on the fishing of Pacific Bluefin Tuna may result. This implication from the whaling issue is potentially helpful to predict the development of international relations and conservation regarding other endangered species.