Published online by Cambridge University Press: 03 February 2020
This article argues that the concept of diligence provides a useful role in clarifying (and perhaps narrowing) the discretionary powers of the State with respect to the development of natural resources. The claim has two branches. First, the concept of due diligence plays an important role in bridging the normative gap between the harms caused by private actors and the international law of State responsibility. It is the vehicle by which States can be made to assume responsibility for private developments within their jurisdiction and control that cause harm to other States. Second, the concept of due diligence plays an important role (a “generative role”) in teasing out the detailed logical implications of more abstract primary norms such as the duty of prevention. These derivative duties include the duties to make a preliminary assessment of whether the proposed activity may cause a risk of significant transboundary harm: to conduct an environmental impact assessment (EIA) if there is a risk of significant harm and, if the EIA confirms that risk, to notify and consult with respect to possible measures to prevent or mitigate that risk. The article demonstrates both of these claims through an examination of the jurisprudence of the International Court of Justice, the International Tribunal for the Law of the Sea and arbitral awards. Finally, the article applies these claims in the context of possible resource developments in Alaska, British Columbia and Yukon that may have transboundary implications.