국경지역에서의 니카라과의 활동사건과 코스타리카의 산후안강 하안 도로건설 사건의 국제환경법 쟁점

The International Court of Justice(ICJ) has increasingly addressed cases which has legal issues of international environmental law. Certain Activities Carried Out by Nicaragua in the Border Area case (Costa Rica v. Nicaragua)/ Construction of a Road in Costa Rica Along the San Juan River case (Nicaragua v. Costa Rica) which was ruled in 2015 can be included in one of the typical international environmental law cases. The article analyzed legal issues which was raised in the cases, such as territorial sovereignty over disputed territory, violation of international law obligation not to cause serious transfrontier environmental damage and to compensate the damage, with special emphasis on the international environmental law issues. Especially, the article observed the impact on the development of definition of concept, character and status in international law and content and criterion of application of international environmental law issues through the decision and reasoning of the Cases by ICJ. ICJ reaffirmed the obligation of environmental impact assessment and responsibility not to cause significant transfrontier environmental damage as general international law, established customary international law. Furthermore, the Court played important role in the arithmetization of content of the above-mentioned general international law obligations such as constituents of environmental impact assessment, criteria to assess “significant transfrontier damage” for conducting environmental impact assessment and for recognizing the violation of responsibility not to cause transfrontier damage. However, there are some feeling something lacking in the ICJ’s decision on the Case. Based on judicial economy, ICJ did not addressed important legal issues such as whether obligation to carry out environmental impact assessment can be exempted in the situation of emergency, standards for evaluating appropriateness of preliminary risk assessment, and so on.