The Nature and Content of the Obligation to Environmental Impact Assessment in the Light of the ICJ Case Law

Environmental impact assessment refers to the processes of forecasting, identifying and evaluating the effects of projects and development decisions on the environment, human health and the well-being of society.This obligation is a key State’s Commitments to protection of environment and improvement of environmentally sustainable development. The International Court of Justice described this concept in some of its Judgements; in particular in the 2010 Judgement on the Pulp Mills on the River Uruguay and the 2015 judgement on the Construction of a Road in Costa Rica along the San Juan River and Certain Activities Carried Out by Nicaragua in the Border Area . The main question that this paper seeks to answer it is: What is the legal nature and content of this obligation in the light of the ICJ case law? ICJ recognizes the customary nature of the obligation of environmental impact assessment and explains its content.The result of the descriptive-analytical studies of the ICJ Judgements in evaluating this hypothesis confirms the Court's developmental step in identifying the environmental impact assessment as a customary rule,In addition, the Court’s states that the content of the environmental impact assessment should be determined in each case, but in any way, monitoring the environmental impacts of developmental activities is not only necessary before doing them rather they need to be continued during such actions.