Despite some important contributions and clarifications, particularly on the obligation of due diligence and environmental impact assessments, the judgment of 20 April 2010 does not live up to expectations. The International Court of Justice globally upholds a restrictive interpretation of the obligations to prevent environmental harm in a transboundary context. Its reasoning relies on an artificial distinction between procedural and substantive obligations, which prevents awarding any form of compensation other than satisfaction. Beyond the statements in favour of sustainable development, this case symbolises the international judge’s difficulty to find the right balance between economic development and environmental protection.