'International Law is Part of the Law of the Land': True or False?

This article addresses the question stated in its title by considering not only the role of national courts but also the roles of national legislatures and executives. That emphasis is called for because most of international law most of the time operates through national, rather than international, institutions and in particular through the executive and the legislature. Before I get to those national institutions, I consider two undisputed propositions of law, the varying characteristics of rules of international law and the impact of those characteristics on different national constitutional and legal systems.