The United Nations is frequently the object of blame for ""failing' ' to act in response to what are deemed to be ethical imperatives. Implicit in such condemnations is an understanding of the United Nations as a body that has moral duties, and possesses the various capacities for deliberating and acting that would make this a reasonable conception. Yet this portrayal of the United Nations as a moral agent is one that should only be invoked with great care, and some qualification. By constructing a model of ""institutional moral agency'', and examining whether the United Nations meets its criteria, this article aims to offer a preliminary account of the internal features, and enabling conditions that would allow the United Nations to bear the related burdens of duty and blame in international politics. It also suggests whoâ€”or whatâ€” might bear these burdens when the United Nations is incapable of acting.