Status of Environmental Obligations in International Investment Law

The relationship between international investment law and international environment law is a contradictory relationship in purposes but concurrent in practice. The purpose of the former is personal economical interests, while the latter is collective human interests. However, the atmosphere in which both of them are applied, is the same. These two branches of international law are definable out of traditional international law which is State-centric; since the international investment law concerns the relationships of State actors with non-State actors who are away from the principle of equality of sovereigns, and international environmental law concerns the common heritage of mankind at all which is away from the principle of consent of States. The present essay with special reference to the last case at the ICJ called “The Case Concerning Pulp Mills on the River, Argentina vs Uruguay” and other common sources of these two laws, tries to explore and analyze existent conflicts in applying two laws. At the end, author suggests some working methods for reconciling of international investment law and international environment law. A balance between these two branches of international law not only would prevent detriments to national and foreign investors- that existence of international economic depends on them- but also would prevent harms to environment which is necessary milieu for investment.