How and Why International Law Binds International Organizations

For decades, controversy has dogged claims about whether and to what extent international law binds international organizations (IOs) like the United Nations and the International Monetary Fund. The question has important consequences for humanitarian law, economic rights, and environmental protection. In this article, I aim to resolve the controversy by supplying a theory about when and how international law binds IOs. I conclude that international law binds IOs to the same degree that it binds states. That is, IOs are not more extensively or more readily bound; nor are they less extensively or less readily bound. This means that IOs, like states, are not bound by treaties without their consent, with some very narrow exceptions that apply to states and IOs alike. It means that IOs, like states, are bound by jus cogens rules, which are mandatory for states and IOs alike. And it means that IOs, like states, are bound by general international law—but only as a default matter. Like states, IOs may contract around such default rules, except to the extent that individual IOs lack the capacity to do so because of their limited authorities.