What Is International Law?
How law works in a world of sovereign states — no global police, no world government, yet rules that (mostly) hold.
Law Without a Government
International law is the set of rules that govern relations between states and, increasingly, other actors like international organizations and individuals. Unlike domestic law, there is no world government to legislate, no global police force to enforce, and no compulsory court system.
So why do states follow it? Mostly because it serves their interests. International law reduces uncertainty, facilitates cooperation, and provides legitimacy. A state that routinely violates its treaty obligations will find fewer willing partners. Compliance is driven by reciprocity, reputation, and the desire for a predictable international order — not by force.
That said, enforcement is the perennial weakness. When a powerful state violates international law (Russia's invasion of Ukraine, the US invasion of Iraq), mechanisms for holding it accountable are limited.