The author discusses various legal principles for export control, such as territoriality or the principle of the place of origin, as a basis for legal export controls. The effectiveness, protection, universality, and nationality principles are considered for re-export control, with different focuses in Anglo-American and German law. New trends, such as the "subjugation declaration" or an "origin theory" for technological goods, are also discussed. The author hopes that the discussion around the UN Code of Conduct for Transnational Corporations and an impartial weighing of international facts by national courts will lead to new developments in economic law. The author concludes with a comprehensive summary of the views up to 1988 and provides thoughts beyond the publication date. Thomas M. Franck's book addresses the neglect of legal and philosophical questions in international libertarian theory. He argues that the international system today is a functioning community with a concept of obligation. The main part of the book explores what characteristics of a norm or rule increase its legitimacy. Four elements—determinacy, symbolic validation, coherence, and adherence—are discussed. These elements are essential for understanding the legitimacy of international norms. Franck's analysis is comprehensive but somewhat impressionistic. He distinguishes legitimacy from justice, explaining that while legitimacy is crucial, justice plays a minor role in international relations. Franck argues that legitimacy and justice are interdependent, with legitimacy supporting the predictability and stability of the international system, and justice requiring legitimacy to be realized. The book raises important questions about the meaning of legitimacy for the international system but does not provide a definitive answer. The book is a valuable contribution to the understanding of international law and the role of legitimacy in international relations.The author discusses various legal principles for export control, such as territoriality or the principle of the place of origin, as a basis for legal export controls. The effectiveness, protection, universality, and nationality principles are considered for re-export control, with different focuses in Anglo-American and German law. New trends, such as the "subjugation declaration" or an "origin theory" for technological goods, are also discussed. The author hopes that the discussion around the UN Code of Conduct for Transnational Corporations and an impartial weighing of international facts by national courts will lead to new developments in economic law. The author concludes with a comprehensive summary of the views up to 1988 and provides thoughts beyond the publication date. Thomas M. Franck's book addresses the neglect of legal and philosophical questions in international libertarian theory. He argues that the international system today is a functioning community with a concept of obligation. The main part of the book explores what characteristics of a norm or rule increase its legitimacy. Four elements—determinacy, symbolic validation, coherence, and adherence—are discussed. These elements are essential for understanding the legitimacy of international norms. Franck's analysis is comprehensive but somewhat impressionistic. He distinguishes legitimacy from justice, explaining that while legitimacy is crucial, justice plays a minor role in international relations. Franck argues that legitimacy and justice are interdependent, with legitimacy supporting the predictability and stability of the international system, and justice requiring legitimacy to be realized. The book raises important questions about the meaning of legitimacy for the international system but does not provide a definitive answer. The book is a valuable contribution to the understanding of international law and the role of legitimacy in international relations.