From wikipedia.
International law, also known as
public international law or
law of nations,
[1] is the set of rules, norms, and standards generally regarded and accepted in relations between
nations.
[2][3] It establishes normative guidelines and a common conceptual framework for states to follow across a broad range of domains, including war, diplomacy, human rights, commerce, and environmental preservation. International law thus provides a mean for states to practice more stable, consistent, and organized international relations.
[4]