The Academy is an institution for the study and teaching of public and private international law and related subjects. Its purpose is to encourage a thorough and impartial examination of the problems arising from international relations in the field of law. The courses deal with the theoretical and practical aspects of the subject, including legislation and case law. All courses at the Academy are, in principle, published in the language in which they were delivered in the Collected Courses of the Hague Academy of International Law. The book includes: the legal position in international law of heads of states, heads of governments and foreign ministers, by Sir Arthur Watts, KCMG, QC; maintenance obligations in the conflict of laws, by Dieter Martiny; international liability for the injurious consequences of acts not prohibited by international law and protection of the environment, by Julio Barboza.