Erga Omnes Norms, Institutionalization, and Constitutionalism in International Law

Erga omnes norms are those that give third-party states, rather than just the victim, legal claims against states that violate them. This paper argues that ordinary twoparty norms arise when states recognize that a norm violation injures only one state and that other states that seek to retaliate on that state's behalf are likely using the violation as a pretext for predatory behavior. Erga omnes norms arise when states recognize that a norm violation injures multiple states and that states have an incentive to free ride rather than retaliate against the violator.