Traditional international law was firmly rooted in the assumption that no international obligation could ever trump the national public interest. This sovereigntist account of public interest has been replaced by a constitutionalist account. Hence, human rights law and trade law allow for national public interest considerations, but the international agreements require states to submit their policies to international adjudication. The study gives a comprehensive overview of the case law of the Strasbourg organs, of the ECJ and of the WTO dispute settlement bodies with regard to the so-called escape clauses of the respective treaties. Recently, a third communal account of public interest has become important. A global common good requires international law to adapt its structures and to overcome its horizontal architecture. The study investigates into the various doctrinal elements which are invoked in the name of a global public interest, such as jus cogens, norms erga omnes or the 'common heritage of mankind'. Original in its approach, the study concludes that the use of ordre public in private international law may be a way of accommodating universal conceptions of the public interest with national conceptions.
