This book explores the extent to which contemporary international law expects states to take into account the interests of others, namely third states or their citizens when they form and implement their policies, negotiate agreements, and in general conduct their relations with other states. The contributions to this book also inquire whether international law imposes on states in certain situations not only the duty to consider the interests of people outside their territory or control but also the duty to accommodate them—at least to a certain extent. The book considers various manifestations of what has been described as community interests in most areas regulated by international law. Accordingly, this book takes stock of the state of contemporary international law and observes the extent to which the law has in fact evolved from a legal system based on more or less specific consent and aimed at promoting particular interests of states to one that is more generally oriented toward collectively protecting common interests and values. By systematically covering different areas of law, we are asking in each area whether states are required to take into account the interests and rights of third states (or of the persons under their jurisdiction or control). The book does not provide clear answers in favor of a simple progress narrative, but assesses the degree to which elements of one or the other paradigm coexist and interact in different fields of international law.