What Is International Law? Foundations of Global Governance
International law provides the legal framework for relations among states, international organizations, peoples, individuals, courts, and other global actors. This introductory article explains how international law structures diplomacy, treaties, trade, environmental protection, human rights, armed conflict, maritime navigation, public health cooperation, and international institutions. It distinguishes public international law from domestic law and private international law, introduces core sources such as treaties, custom, general principles, judicial decisions, and scholarly writings, and explains why international law operates as a decentralized legal order rather than a domestic-style hierarchy. It also examines everyday examples of international law, the role of the United Nations and International Court of Justice, the question of whether international law is “really law,” and the field’s unresolved tensions around empire, decolonization, unequal power, selective enforcement, and global governance.








