Recent resolutions of the United Nations Security Council, notably those resulting in the freezing of assets of individuals and organisations suspected of involvement in international terrorism, have had far-reaching consequences for member states and individuals. In addition, they might conflict with international human rights standards that are binding on the Security Council itself. In light of the limited possibility for reviewing the legality of these resolutions on the international level, individuals have recently begun to challenge their implementation on the national and regional level. This emerging practice raises the question whether states and regional organisations such as the EU can engage in such review and, if so, to what extent. The book provides academics, practitioners and policy makers with a variety of legal insights into this question.